package Anvil::Tools::Database;
# 
# This module contains methods related to databases.
# 

use strict;
use warnings;
use DBI;
use Scalar::Util qw(weaken isweak);
use Data::Dumper;
use Time::HiRes qw(gettimeofday tv_interval);
use Text::Diff;

our $VERSION  = "3.0.0";
my $THIS_FILE = "Database.pm";

### Methods;
# archive_database
# check_lock_age
# configure_pgsql
# connect
# disconnect
# get_fences
# get_host_from_uuid
# get_hosts
# get_hosts_info
# get_job_details
# get_jobs
# get_local_uuid
# get_mail_servers
# get_notifications
# get_recipients
# get_upses
# initialize
# insert_or_update_anvils
# insert_or_update_bridges
# insert_or_update_bonds
# insert_or_update_fences
# insert_or_update_file_locations
# insert_or_update_files
# insert_or_update_host_keys
# insert_or_update_hosts
# insert_or_update_ip_addresses
# insert_or_update_jobs
# insert_or_update_mail_servers
# insert_or_update_manifests
# insert_or_update_network_interfaces
# insert_or_update_notifications
# insert_or_update_mac_to_ip
# insert_or_update_oui
# insert_or_update_recipients
# insert_or_update_sessions
# insert_or_update_states
# insert_or_update_upses
# insert_or_update_users
# insert_or_update_variables
# lock_file
# locking
# manage_anvil_conf
# mark_active
# query
# quote
# read
# read_variable
# refresh_timestamp
# resync_databases
# write
# _archive_table
# _find_behind_database
# _mark_database_as_behind
# _test_access

=pod

=encoding utf8

=head1 NAME

Anvil::Tools::Database

Provides all methods related to managing and accessing databases.

=head1 SYNOPSIS

 use Anvil::Tools;

 # Get a common object handle on all Anvil::Tools modules.
 my $anvil = Anvil::Tools->new();
 
 # Access to methods using '$anvil->Database->X'. 
 # 
 # Example using 'get_local_uuid()';
 my $local_id = $anvil->Database->get_local_uuid;

=head1 METHODS

Methods in this module;

=cut
sub new
{
	my $class = shift;
	my $self  = {};
	
	bless $self, $class;
	
	return ($self);
}

# Get a handle on the Anvil::Tools object. I know that technically that is a sibling module, but it makes more 
# sense in this case to think of it as a parent.
sub parent
{
	my $self   = shift;
	my $parent = shift;
	
	$self->{HANDLE}{TOOLS} = $parent if $parent;
	
	# Defend against memory leads. See Scalar::Util'.
	if (not isweak($self->{HANDLE}{TOOLS}))
	{
		weaken($self->{HANDLE}{TOOLS});
	}
	
	return ($self->{HANDLE}{TOOLS});
}


#############################################################################################################
# Public methods                                                                                            #
#############################################################################################################

=head2 archive_database

This method takes an array reference of database tables and check each to see if their history schema version needs to be archived or not.

Parameters;

=head3 tables (required, hash reference)

This is an B<< array reference >> of tables to archive. 

B<< NOTE >>: The array is processed in B<< reverse >> order! This is done to allow the same array used to create/sync tables to be used without modification (foreign keys will be archived/removed before primary keys)

=cut
sub archive_database
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->archive_database()" }});
	
	my $tables = defined $parameter->{tables} ? $parameter->{tables} : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { tables => $tables }});
	
	# If not given tables, use the system tables.
	if (not $tables)
	{
		$tables = $anvil->data->{sys}{database}{check_tables};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { tables => $tables }});
	}
	
	# If this isn't a dashboard, exit. 
	my $host_type = $anvil->System->get_host_type();
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_type => $host_type }});
	if ($host_type ne "dashboard")
	{
		# Not a dashboard, don't archive
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0452"});
		return(1);
	}
	
	# If the 'tables' parameter is an array reference, add it to 'sys::database::check_tables' (creating
	# it, if needed).
	if (ref($tables) ne "ARRAY")
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0432"});
		return(1);
	}
	
	# Only the root user can archive the database so that the archived files can be properly secured.
	if (($< != 0) && ($> != 0))
	{
		# Not root
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0188"});
		return(1);
	}
	
	# Make sure I have sane values.
	$anvil->data->{sys}{database}{archive}{compress}  = 1     if not defined $anvil->data->{sys}{database}{archive}{compress};
	$anvil->data->{sys}{database}{archive}{count}     = 10000 if not defined $anvil->data->{sys}{database}{archive}{count};
	$anvil->data->{sys}{database}{archive}{division}  = 25000 if not defined $anvil->data->{sys}{database}{archive}{division};
	$anvil->data->{sys}{database}{archive}{trigger}   = 20000 if not defined $anvil->data->{sys}{database}{archive}{trigger};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		"sys::database::archive::compress" => $anvil->data->{sys}{database}{archive}{compress},
		"sys::database::archive::count"    => $anvil->data->{sys}{database}{archive}{count},
		"sys::database::archive::division" => $anvil->data->{sys}{database}{archive}{division},
		"sys::database::archive::trigger"  => $anvil->data->{sys}{database}{archive}{trigger},
	}});
	
	# Make sure the archive directory is sane.
	if ((not defined $anvil->data->{sys}{database}{archive}{directory}) or ($anvil->data->{sys}{database}{archive}{directory} !~ /^\//))
	{
		$anvil->data->{sys}{database}{archive}{directory} = "/usr/local/anvil/archives/";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"sys::database::archive::directory" => $anvil->data->{sys}{database}{archive}{directory},
		}});
	}
	if (not -d $anvil->data->{sys}{database}{archive}{directory})
	{
		my $failed = $anvil->Storage->make_directory({
			debug     => $debug,
			directory => $anvil->data->{sys}{database}{archive}{directory},
			mode      => "0700",
			user      => "root",
			group     => "root",
		});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { failed => $failed }});
		if ($failed)
		{
			# No directory to archive into...
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, priority => "err", key => "error_0098", variables => { 
				directory => $anvil->data->{sys}{database}{archive}{directory},
			}});
			return("!!error!!");
		}
	}
	
	# Make sure the numerical values are sane
	if ($anvil->data->{sys}{database}{archive}{count} !~ /^\d+$/)
	{
		# Use the set value if it just has commas.
		$anvil->data->{sys}{database}{archive}{count} =~ s/,//g;
		$anvil->data->{sys}{database}{archive}{count} =~ s/\.\d+$//g;
		if ($anvil->data->{sys}{database}{archive}{count} !~ /^\d+$/)
		{
			$anvil->data->{sys}{database}{archive}{count} = 10000;
		}
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"sys::database::archive::count" => $anvil->data->{sys}{database}{archive}{count},
		}});
	}
	if ($anvil->data->{sys}{database}{archive}{division} !~ /^\d+$/)
	{
		# Use the set value if it just has commas.
		$anvil->data->{sys}{database}{archive}{division} =~ s/,//g;
		$anvil->data->{sys}{database}{archive}{division} =~ s/\.\d+$//g;
		if ($anvil->data->{sys}{database}{archive}{division} !~ /^\d+$/)
		{
			$anvil->data->{sys}{database}{archive}{division} = 25000;
		}
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"sys::database::archive::division" => $anvil->data->{sys}{database}{archive}{division},
		}});
	}
	if ($anvil->data->{sys}{database}{archive}{trigger} !~ /^\d+$/)
	{
		# Use the set value if it just has commas.
		$anvil->data->{sys}{database}{archive}{trigger} =~ s/,//g;
		$anvil->data->{sys}{database}{archive}{trigger} =~ s/\.\d+$//g;
		if ($anvil->data->{sys}{database}{archive}{trigger} !~ /^\d+$/)
		{
			$anvil->data->{sys}{database}{archive}{trigger} = 20000;
		}
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"sys::database::archive::trigger" => $anvil->data->{sys}{database}{archive}{trigger},
		}});
	}
	
	# Is archiving disabled?
	if (not $anvil->data->{sys}{database}{archive}{trigger})
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0189"});
		return(1);
	}
	
	# We'll use the list of tables created for _find_behind_databases()'s 'sys::database::check_tables' 
	# array, but in reverse so that tables with primary keys (first in the array) are archived last.
	foreach my $table (reverse(@{$tables}))
	{
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { table => $table }});
		$anvil->Database->_archive_table({debug => $debug, table => $table});
	}
	
	return(0);
}


=head2 check_lock_age

This checks to see if 'sys::database::local_lock_active' is set. If it is, its age is checked and if the age is >50% of sys::database::locking_reap_age, it will renew the lock.

=cut
sub check_lock_age
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->check_lock_age()" }});
	
	# Make sure we've got the 'sys::database::local_lock_active' and 'reap_age' variables set.
	if ((not defined $anvil->data->{sys}{database}{local_lock_active}) or ($anvil->data->{sys}{database}{local_lock_active} =~ /\D/))
	{
		$anvil->data->{sys}{database}{local_lock_active} = 0;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::local_lock_active" => $anvil->data->{sys}{database}{local_lock_active} }});
	}
	if ((not $anvil->data->{sys}{database}{locking_reap_age}) or ($anvil->data->{sys}{database}{locking_reap_age} =~ /\D/))
	{
		$anvil->data->{sys}{database}{locking_reap_age} = 300;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::local_lock_active" => $anvil->data->{sys}{database}{local_lock_active} }});
	}
	
	# If I have an active lock, check its age and also update the Anvil! lock file.
	my $renewed = 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::local_lock_active" => $anvil->data->{sys}{database}{local_lock_active} }});
	if ($anvil->data->{sys}{database}{local_lock_active})
	{
		my $current_time  = time;
		my $lock_age      = $current_time - $anvil->data->{sys}{database}{local_lock_active};
		my $half_reap_age = int($anvil->data->{sys}{database}{locking_reap_age} / 2);
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			current_time  => $current_time,
			lock_age      => $lock_age,
			half_reap_age => $half_reap_age, 
		}});
		
		if ($lock_age > $half_reap_age)
		{
			# Renew the lock.
			$anvil->Database->locking({renew => 1});
			$renewed = 1;
			
			# Update the lock age
			$anvil->data->{sys}{database}{local_lock_active} = time;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::local_lock_active" => $anvil->data->{sys}{database}{local_lock_active} }});
			
			# Update the lock file
			my $lock_file_age = $anvil->Database->lock_file({'do' => "set"});
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { lock_file_age => $lock_file_age }});
		}
	}
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { renewed => $renewed }});
	return($renewed);
}


=head2 configure_pgsql

This configures the local database server. Specifically, it checks to make sure the daemon is running and starts it if not. It also checks the C<< pg_hba.conf >> configuration to make sure it is set properly to listen on this machine's IP addresses and interfaces.

If the system is already configured, this method will do nothing, so it is safe to call it at any time.

If the method completes, C<< 0 >> is returned. If this method is called without C<< root >> access, it returns C<< 1 >> without doing anything. If there is a problem, C<< !!error!! >> is returned.

=cut
sub configure_pgsql
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->configure_pgsql()" }});
	
	# The local host_uuid is the ID of the local database, so get that.
	my $uuid = $anvil->Get->host_uuid();
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { uuid => $uuid }});
	
	# If we're not running with root access, return.
	if (($< != 0) && ($> != 0))
	{
		# This is a minor error as it will be hit by every unpriviledged program that connects to the
		# database(s).
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, priority => "alert", key => "log_0113"});
		return(1);
	}
	
	# First, is it running?
	my $running = $anvil->System->check_daemon({debug => $debug, daemon => $anvil->data->{sys}{daemon}{postgresql}});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { running => $running }});
	
	if (not $running)
	{
		# Do we need to initialize the databae?
		if (not -e $anvil->data->{path}{configs}{'pg_hba.conf'})
		{
			# Initialize.
			my ($output, $return_code) = $anvil->System->call({debug => $debug, shell_call => $anvil->data->{path}{exe}{'postgresql-setup'}." initdb", source => $THIS_FILE, line => __LINE__});
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { output => $output, return_code => $return_code }});
			
			# Did it succeed?
			if (not -e $anvil->data->{path}{configs}{'pg_hba.conf'})
			{
				# Failed... 
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0050"});
				return("!!error!!");
			}
			else
			{
				# Initialized!
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0055"});
				
				# Enable it on boot.
				my $return_code = $anvil->System->enable_daemon({debug => $debug, daemon => $anvil->data->{sys}{daemon}{postgresql}});
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { return_code => $return_code }});
			}
		}
	}
	
	# Setup postgresql.conf, if needed
	my $postgresql_conf        = $anvil->Storage->read_file({debug => $debug, file => $anvil->data->{path}{configs}{'postgresql.conf'}});
	my $update_postgresql_file = 1;
	my $new_postgresql_conf    = "";
	foreach my $line (split/\n/, $postgresql_conf)
	{
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { line => $line }});
		if ($line =~ /^listen_addresses = '\*'/)
		{
			# No need to update.
			$update_postgresql_file = 0;
			last;
		}
		elsif ($line =~ /^#listen_addresses = 'localhost'/)
		{
			# Inject the new listen_addresses
			$new_postgresql_conf .= "# This has been changed by Anvil::Tools::Database->configure_pgsql() to enable\n";
			$new_postgresql_conf .= "# listening on all interfaces.\n";
			$new_postgresql_conf .= "#listen_addresses = 'localhost'\n";
			$new_postgresql_conf .= "listen_addresses = '*'\n";
		}
		$new_postgresql_conf .= $line."\n";
	}
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { update_postgresql_file => $update_postgresql_file }});
	if ($update_postgresql_file)
	{
		# Back up the existing one, if needed.
		my $postgresql_backup = $anvil->data->{path}{directories}{backups}."/pgsql/postgresql.conf";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { postgresql_backup => $postgresql_backup }});
		if (not -e $postgresql_backup)
		{
			$anvil->Storage->copy_file({
				debug       => $debug, 
				source_file => $anvil->data->{path}{configs}{'postgresql.conf'}, 
				target_file => $postgresql_backup,
			});
		}
		
		# Write the updated one.
		$anvil->Storage->write_file({
			debug     => $debug, 
			file      => $anvil->data->{path}{configs}{'postgresql.conf'}, 
			body      => $new_postgresql_conf,
			user      => "postgres", 
			group     => "postgres",
			mode      => "0600",
			overwrite => 1,
		});
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0056", variables => { file => $anvil->data->{path}{configs}{'postgresql.conf'} }});
	}
	
	# Setup pg_hba.conf now, if needed.
	my $pg_hba_conf        = $anvil->Storage->read_file({debug => $debug, file => $anvil->data->{path}{configs}{'pg_hba.conf'}});
	my $update_pg_hba_file = 1;
	my $new_pg_hba_conf    = "";
	foreach my $line (split/\n/, $pg_hba_conf)
	{
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { line => $line }});
		if ($line =~ /^host\s+all\s+all\s+all\s+md5$/)
		{
			# No need to update.
			$update_pg_hba_file = 0;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { update_pg_hba_file => $update_pg_hba_file }});
			last;
		}
		elsif ($line =~ /^# TYPE\s+DATABASE/)
		{
			# Inject the new listen_addresses
			$new_pg_hba_conf .= $line."\n";
			$new_pg_hba_conf .= "host\tall\t\tall\t\tall\t\t\tmd5\n";
		}
		else
		{
			$new_pg_hba_conf .= $line."\n";
		}
	}
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { update_pg_hba_file => $update_pg_hba_file }});
	if ($update_pg_hba_file)
	{
		# Back up the existing one, if needed.
		my $pg_hba_backup = $anvil->data->{path}{directories}{backups}."/pgsql/pg_hba.conf";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { pg_hba_backup => $pg_hba_backup }});
		if (not -e $pg_hba_backup)
		{
			$anvil->Storage->copy_file({
				source_file => $anvil->data->{path}{configs}{'pg_hba.conf'}, 
				target_file => $pg_hba_backup,
			});
		}
		
		# Write the new one.
		$anvil->Storage->write_file({
			file      => $anvil->data->{path}{configs}{'pg_hba.conf'}, 
			body      => $new_pg_hba_conf,
			user      => "postgres", 
			group     => "postgres",
			mode      => "0600",
			overwrite => 1,
		});
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0057", variables => { file => $anvil->data->{path}{configs}{'postgresql.conf'} }});
	}
	
	# Start or restart the daemon?
	if (not $running)
	{
		# Start the daemon.
		my $return_code = $anvil->System->start_daemon({daemon => $anvil->data->{sys}{daemon}{postgresql}});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { return_code => $return_code }});
		if ($return_code eq "0")
		{
			# Started the daemon.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0059"});
		}
		else
		{
			# Failed to start
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0094"});
			return("!!error!!");
		}
	}
	elsif (($update_postgresql_file) or ($update_pg_hba_file))
	{
		# Reload
		my $return_code = $anvil->System->start_daemon({daemon => $anvil->data->{sys}{daemon}{postgresql}});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { return_code => $return_code }});
		if ($return_code eq "0")
		{
			# Reloaded the daemon.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0112"});
		}
		else
		{
			# Failed to reload
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0111"});
		}
	}
	
	# Create the .pgpass file, if needed.
	my $created_pgpass = 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, secure => 1, list => { 
		'path::secure::postgres_pgpass' => $anvil->data->{path}{secure}{postgres_pgpass},
		"database::${uuid}::password"   => $anvil->data->{database}{$uuid}{password}, 
	}});
	if ((not -e $anvil->data->{path}{secure}{postgres_pgpass}) && ($anvil->data->{database}{$uuid}{password}))
	{
		my $body = "*:*:*:postgres:".$anvil->data->{database}{$uuid}{password};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, secure => 1, list => { body => $body }});
		$anvil->Storage->write_file({
			file      => $anvil->data->{path}{secure}{postgres_pgpass},  
			body      => $body,
			user      => "postgres", 
			group     => "postgres",
			mode      => "0600",
			overwrite => 1,
			secure    => 1,
		});
		if (-e $anvil->data->{path}{secure}{postgres_pgpass})
		{
			$created_pgpass = 1;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { created_pgpass => $created_pgpass }});
		}
	}
	
	# Does the database user exist?
	my $create_user   = 1;
	my $database_user = $anvil->data->{database}{$uuid}{user} ? $anvil->data->{database}{$uuid}{user} : $anvil->data->{sys}{database}{user};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { database_user => $database_user }});
	if (not $database_user)
	{
		# No database user defined
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0099", variables => { uuid => $uuid }});
		return("!!error!!");
	}
	my ($user_list, $return_code) = $anvil->System->call({shell_call => $anvil->data->{path}{exe}{su}." - postgres -c \"".$anvil->data->{path}{exe}{psql}." template1 -c 'SELECT usename, usesysid FROM pg_catalog.pg_user;'\"", source => $THIS_FILE, line => __LINE__});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { user_list => $user_list, return_code => $return_code }});
	foreach my $line (split/\n/, $user_list)
	{
		if ($line =~ /^ $database_user\s+\|\s+(\d+)/)
		{
			# User exists already
			my $uuid = $1;
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0060", variables => { user => $database_user, uuid => $uuid }});
			$create_user = 0;
			last;
		}
	}
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { create_user => $create_user }});
	if ($create_user)
	{
		# Create the user
		my ($create_output, $return_code) = $anvil->System->call({shell_call => $anvil->data->{path}{exe}{su}." - postgres -c \"".$anvil->data->{path}{exe}{createuser}." --no-superuser --createdb --no-createrole $database_user\"", source => $THIS_FILE, line => __LINE__});
		(my $user_list, $return_code)     = $anvil->System->call({shell_call => $anvil->data->{path}{exe}{su}." - postgres -c \"".$anvil->data->{path}{exe}{psql}." template1 -c 'SELECT usename, usesysid FROM pg_catalog.pg_user;'\"", source => $THIS_FILE, line => __LINE__});
		my $user_exists   = 0;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { create_output => $create_output, user_list => $user_list }});
		foreach my $line (split/\n/, $user_list)
		{
			if ($line =~ /^ $database_user\s+\|\s+(\d+)/)
			{
				# Success!
				my $uuid = $1;
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0095", variables => { user => $database_user, uuid => $uuid }});
				$user_exists = 1;
				last;
			}
		}
		if (not $user_exists)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0096", variables => { user => $database_user }});
			return("!!error!!");
		}
		
		# Update/set the passwords.
		if ($anvil->data->{database}{$uuid}{password})
		{
			foreach my $user ("postgres", $database_user)
			{
				my ($update_output, $return_code) = $anvil->System->call({secure => 1, shell_call => $anvil->data->{path}{exe}{su}." - postgres -c \"".$anvil->data->{path}{exe}{psql}." template1 -c \\\"ALTER ROLE $user WITH PASSWORD '".$anvil->data->{database}{$uuid}{password}."';\\\"\"", source => $THIS_FILE, line => __LINE__});
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, secure => 1, list => { update_output => $update_output, return_code => $return_code }});
				foreach my $line (split/\n/, $user_list)
				{
					if ($line =~ /ALTER ROLE/)
					{
						# Password set
						$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0100", variables => { user => $user }});
					}
				}
			}
		}
	}
	
	# Create the database, if needed.
	my $create_database = 1;
	my $database_name   = defined $anvil->data->{database}{$uuid}{name} ? $anvil->data->{database}{$uuid}{name} : $anvil->data->{sys}{database}{name};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { database_name => $database_name }});
	
	(my $database_list, $return_code) = $anvil->System->call({shell_call => $anvil->data->{path}{exe}{su}." - postgres -c \"".$anvil->data->{path}{exe}{psql}." template1 -c 'SELECT datname FROM pg_catalog.pg_database;'\"", source => $THIS_FILE, line => __LINE__});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { database_list => $database_list, return_code => $return_code }});
	foreach my $line (split/\n/, $database_list)
	{
		if ($line =~ /^ $database_name$/)
		{
			# Database already exists.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0105", variables => { database => $database_name }});
			$create_database = 0;
			last;
		}
	}
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { create_database => $create_database }});
	if ($create_database)
	{
		my ($create_output, $return_code) = $anvil->System->call({shell_call => $anvil->data->{path}{exe}{su}." - postgres -c \"".$anvil->data->{path}{exe}{createdb}."  --owner $database_user $database_name\"", source => $THIS_FILE, line => __LINE__});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { create_output => $create_output, return_code => $return_code }});
		
		my $database_exists               = 0;
		(my $database_list, $return_code) = $anvil->System->call({shell_call => $anvil->data->{path}{exe}{su}." - postgres -c \"".$anvil->data->{path}{exe}{psql}." template1 -c 'SELECT datname FROM pg_catalog.pg_database;'\"", source => $THIS_FILE, line => __LINE__});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { database_list => $database_list, return_code => $return_code }});
		foreach my $line (split/\n/, $database_list)
		{
			if ($line =~ /^ $database_name$/)
			{
				# Database created
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0110", variables => { database => $database_name }});
				$database_exists = 1;
				last;
			}
		}
		if (not $database_exists)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0109", variables => { database => $database_name }});
			return("!!error!!");
		}
	}
	
	# Remove the temporary password file.
	if (($created_pgpass) && (-e $anvil->data->{path}{secure}{postgres_pgpass}))
	{
		unlink $anvil->data->{path}{secure}{postgres_pgpass};
		if (-e $anvil->data->{path}{secure}{postgres_pgpass})
		{
			# Failed to unlink the file.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "alert", key => "log_0107"});
		}
	}
	
	# Make sure the psql TCP port is open.
	$anvil->data->{database}{$uuid}{port} = 5432 if not $anvil->data->{database}{$uuid}{port};
	my $port_status = $anvil->System->manage_firewall({
		task        => "open",
		port_number => $anvil->data->{database}{$uuid}{port},
	});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { port_status => $port_status }});
	
	return(0);
}


=head2 connect_to_databases

This method tries to connect to all databases it knows of. To define databases for a machine to connect to, load a configuration file with the following parameters;

 database::1::host		=	an-striker01.alteeve.com
 database::1::port		=	5432
 database::1::password		=	Initial1
 database::1::ping		=	0.25
 
 database::2::host		=	an-striker02.alteeve.com
 database::2::port		=	5432
 database::2::password		=	Initial1
 database::2::ping		=	0.25

Please see the comments in /etc/anvil/anvil.conf for more information on how to use the above variables.
 
The C<< 1 >> and C<< 2 >> are the IDs of the given databases. They can be any number and do not need to be sequential, they just need to be unique. 

This module will return the number of databases that were successfully connected to. This makes it convenient to check and exit if no databases are available using a check like;

 my $database_count = $anvil->Database->connect({file => $THIS_FILE});
 if($database_count)
 {
 	# Connected to: [$database_count] database(s)!
 }
 else
 {
 	# No databases available, exiting.
 }

Parameters;

=head3 check_if_configured (optional, default '0')

If set to C<< 1 >>, and if this is a locally hosted database, a check will be made to see if the database is configured. If it isn't, it will be configured.

B<< Note >>: This is expensive, so should only be called periodically. This will do nothing if not called with C<< root >> access, or if the database is not local.

=head3 db_uuid (optional)

If set, the connection will be made only to the database server matching the UUID.

=head3 no_ping (optional, default '0')

If set to C<< 1 >>, no attempt to ping a target before connection will happen, even if C<< database::<uuid>::ping = 1 >> is set.

=head3 source (optional)

The C<< source >> parameter is used to check the special C<< updated >> table one all connected databases to see when that source (program name, usually) last updated a given database. If the date stamp is the same on all connected databases, nothing further happens. If one of the databases differ, however, a resync will be requested.

If not defined, the core database will be checked.

If this is not set, no attempt to resync the database will be made.

=head3 sql_file (optional)

This is the SQL schema file that will be used to initialize the database, if the C<< test_table >> isn't found in a given database that is connected to. By default, this is C<< path::sql::anvil.sql >> (C<< /usr/share/perl/AN/Tools.sql >> by default). 

=head3 tables (optional)

This is an optional array reference of of tables to specifically check when connecting to databases. Each entry is treated as a table name, and that table's most recent C<< modified_date >> time stamp will be read. If a column name in the table ends in C<< _host_uuid >>, then the check and resync will be restricted to entries in that column matching the current host's C<< sys::host_uuid >>. If the table does not have a corresponding table in the C<< history >> schema, then only the public table will be synced. 

Note; The array order is used to allow you to ensure tables with primary keys are synchronyzed before tables with foreign keys. As such, please be aware of the order the table hash references are put into the array reference.

Example use;

 $anvil->Database->connect({
	tables => ["upses", "ups_batteries"],
 });

If you want to specify a table that is not linked to a host, set the hash variable's value as an empty string.

 $anvil->Database->connect({
	tables => {
		servers => "",
	},
 });

=head3 test_table (optional)

Once connected to the database, a query is made to see if the database needs to be initialized. Usually this is C<< defaults::sql::test_table >> (C<< hosts>> by default). 

If you set this table manually, it will be checked and if the table doesn't exist on a connected database, the database will be initialized with the C<< sql_file >> parameter's file.

=cut
sub connect
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->connect()" }});
	
	my $check_if_configured = defined $parameter->{check_if_configured} ? $parameter->{check_if_configured} : 0;
	my $db_uuid             = defined $parameter->{db_uuid}             ? $parameter->{db_uuid}             : "";
	my $no_ping             = defined $parameter->{no_ping}             ? $parameter->{no_ping}             : 0;
	my $source              = defined $parameter->{source}              ? $parameter->{source}              : "core";
	my $sql_file            = defined $parameter->{sql_file}            ? $parameter->{sql_file}            : $anvil->data->{path}{sql}{'anvil.sql'};
	my $tables              = defined $parameter->{tables}              ? $parameter->{tables}              : "";
	my $test_table          = defined $parameter->{test_table}          ? $parameter->{test_table}          : $anvil->data->{sys}{database}{test_table};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		check_if_configured => $check_if_configured, 
		db_uuid             => $db_uuid,
		no_ping             => $no_ping,
		source              => $source, 
		sql_file            => $sql_file, 
		tables              => $tables, 
		test_table          => $test_table, 
	}});
	
	# If I wasn't passed an array reference of tables, use the core tables.
	if (not $tables)
	{
		$tables = $anvil->data->{sys}{database}{core_tables};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { tables => $tables }});
	}
	
	my $start_time = [gettimeofday];
	#print "Start time: [".$start_time->[0].".".$start_time->[1]."]\n";
	
	$anvil->data->{sys}{database}{timestamp} = "" if not defined $anvil->data->{sys}{database}{timestamp};
	
	# We need the host_uuid before we connect.
	if (not $anvil->data->{sys}{host_uuid})
	{
		$anvil->data->{sys}{host_uuid} = $anvil->Get->host_uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::host_uuid" => $anvil->data->{sys}{host_uuid} }});
	}
	
	# This will be used in a few cases where the local DB ID is needed (or the lack of it being set 
	# showing we failed to connect to the local DB).
	$anvil->data->{sys}{database}{local_uuid} = "";
	
	# This will be set to '1' if either DB needs to be initialized or if the last_updated differs on any node.
	$anvil->data->{sys}{database}{resync_needed} = 0;
	
	# Now setup or however-many connections
	my $seen_connections       = [];
	my $failed_connections     = [];
	my $successful_connections = [];
	foreach my $uuid (sort {$a cmp $b} keys %{$anvil->data->{database}})
	{
		# Periodically, autovivication causes and empty key to appear.
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { uuid => $uuid }});
		next if ((not $uuid) or (not $anvil->Validate->is_uuid({uuid => $uuid})));
		
		if (($db_uuid) && ($db_uuid ne $uuid))
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0191", variables => { db_uuid => $db_uuid, uuid => $uuid }});
			next;
		}
		
		my $driver   = "DBI:Pg";
		my $host     = $anvil->data->{database}{$uuid}{host}     ? $anvil->data->{database}{$uuid}{host}     : ""; # This should fail
		my $port     = $anvil->data->{database}{$uuid}{port}     ? $anvil->data->{database}{$uuid}{port}     : 5432;
		my $name     = $anvil->data->{database}{$uuid}{name}     ? $anvil->data->{database}{$uuid}{name}     : $anvil->data->{sys}{database}{name};
		my $user     = $anvil->data->{database}{$uuid}{user}     ? $anvil->data->{database}{$uuid}{user}     : $anvil->data->{sys}{database}{user};
		my $password = $anvil->data->{database}{$uuid}{password} ? $anvil->data->{database}{$uuid}{password} : "";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			host     => $host,
			port     => $port,
			name     => $name,
			user     => $user, 
			password => $anvil->Log->is_secure($password), 
		}});
		
		# Some places will want to pull up the database user, so in case it isn't set (which is 
		# usual), set it as if we had read it from the config file using the default.
		if (not $anvil->data->{database}{$uuid}{name})
		{
			$anvil->data->{database}{$uuid}{name} = $anvil->data->{sys}{database}{name};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "database::${uuid}::name" => $anvil->data->{database}{$uuid}{name} }});
		}
		
		# If not set, we will always ping before connecting.
		if ((not exists $anvil->data->{database}{$uuid}{ping}) or (not defined $anvil->data->{database}{$uuid}{ping}))
		{
			$anvil->data->{database}{$uuid}{ping} = 1;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "database::${uuid}::ping" => $anvil->data->{database}{$uuid}{ping} }});
		}
		
		# Make sure the user didn't specify the same target twice.
		my $target_host = "$host:$port";
		my $duplicate   = 0;
		foreach my $existing_host (sort {$a cmp $b} @{$seen_connections})
		{
			if ($existing_host eq $target_host)
			{
				# User is connecting to the same target twice.
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0053", variables => { target => $target_host }});
				$duplicate = 1;
			}
		}
		if (not $duplicate)
		{
			push @{$seen_connections}, $target_host;
		}
		next if $duplicate;
		
		# Log what we're doing.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0054", variables => { 
			uuid     => $uuid,
			driver   => $driver,
			host     => $host,
			port     => $port,
			name     => $name,
			user     => $user,
			password => $anvil->Log->is_secure($password),
		}});
		
		### TODO: Can we do a telnet port ping with a short timeout instead of a shell ping call?
		
		# Assemble my connection string
		my $db_connect_string = "$driver:dbname=$name;host=$host;port=$port";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			db_connect_string         => $db_connect_string, 
			"database::${uuid}::ping" => $anvil->data->{database}{$uuid}{ping},
		}});
		if ((not $no_ping) && ($anvil->data->{database}{$uuid}{ping}))
		{
			# Can I ping?
			my ($pinged) = $anvil->Network->ping({
				debug   => $debug, 
				ping    => $host, 
				count   => 1,
				timeout => $anvil->data->{database}{$uuid}{ping},
			});
			
			my $ping_time = tv_interval ($start_time, [gettimeofday]);
			#print "[".$ping_time."] - Pinged: [$host:$port:$name:$user]\n";
			
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { pinged => $pinged }});
			if (not $pinged)
			{
				# Didn't ping and 'database::<uuid>::ping' not set. Record this 
				# in the failed connections array.
				my $debug_level = $anvil->data->{sys}{database}{failed_connection_log_level} ? $anvil->data->{sys}{database}{failed_connection_log_level} : 1;
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug_level, priority => "alert", key => "log_0063", variables => { 
					host => $port ? $host.":".$port : $host,
					name => $name, 
					uuid => $uuid,
				}});
				push @{$failed_connections}, $uuid;
				next;
			}
		}
		
		# Before we try to connect, see if this is a local database and, if so, make sure it's setup.
		my $is_local = $anvil->Network->is_local({debug => $debug, host => $host});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { is_local => $is_local }});
		if ($is_local)
		{
			$anvil->data->{sys}{database}{read_uuid} = $uuid;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::read_uuid" => $anvil->data->{sys}{database}{read_uuid} }});
			
			# If requested, and if running with root access, set it up (or update it) if needed. 
			# This method just returns if nothing is needed.
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				check_if_configured => $check_if_configured,
				real_uid            => $<,
				effective_uid       => $>,
			}});
			if (($check_if_configured) && ($< == 0) && ($> == 0))
			{
				$anvil->Database->configure_pgsql({debug => $debug, uuid => $uuid});
			}
		}
		elsif (not $anvil->data->{sys}{database}{read_uuid})
		{
			$anvil->data->{sys}{database}{read_uuid} = $uuid;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::read_uuid" => $anvil->data->{sys}{database}{read_uuid} }});
		}
		
		# If this isn't a local database, read the target's Anvil! version (if available) and make 
		# sure it matches ours. If it doesn't, skip this database.
		if (not $is_local)
		{
			my $local_version  = $anvil->_anvil_version({debug => $debug});
			my $remote_version = $anvil->Get->anvil_version({
				debug    => $debug, 
				target   => $host,
				password => $password,
			});
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				's1:host'           => $host, 
				's2:remote_version' => $remote_version, 
				's3:local_version'  => $local_version,
			}});
			# TODO: Periodically, we fail to get the remote version. For now, we proceed if 
			#       everything else is OK. Might be better to pause a re-try... To be determined.
			if (($remote_version) && ($remote_version ne $local_version))
			{
				# Version doesn't match, 
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0145", variables => { 
					host           => $host,
					local_version  => $anvil->_anvil_version, 
					target_version => $remote_version,
				}});
				
				# Delete the information about this database. We'll try again on nexy 
				# ->connect().
				delete $anvil->data->{database}{$uuid};
				next;
			}
		}
		
		# Connect!
		my $dbh = "";
		### NOTE: The Database->write() method, when passed an array, will automatically disable 
		###       autocommit, do the bulk write, then commit when done.
		# We connect with fatal errors, autocommit and UTF8 enabled.
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			db_connect_string => $db_connect_string, 
			user              => $user, 
		}});
		eval { $dbh = DBI->connect($db_connect_string, $user, $password, {
			RaiseError     => 1,
			AutoCommit     => 1,
			pg_enable_utf8 => 1
		}); };
		if ($@)
		{
			# Something went wrong...
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, priority => "alert", key => "log_0064", variables => { 
				uuid => $uuid,
				host => $host,
				name => $name,
			}});

			push @{$failed_connections}, $uuid;
			my $message_key = "log_0065";
			my $variables   = { dbi_error => $DBI::errstr };
			if (not defined $DBI::errstr)
			{
				# General error
				$variables = { dbi_error => $@ };
			}
			elsif ($DBI::errstr =~ /No route to host/)
			{
				$message_key = "log_0066";
				$variables   = { target => $host, port => $port };
			}
			elsif ($DBI::errstr =~ /no password supplied/)
			{
				$message_key = "log_0067";
				$variables   = { uuid => $uuid };
			}
			elsif ($DBI::errstr =~ /password authentication failed for user/)
			{
				$message_key = "log_0068";
				$variables   = { 
					uuid => $uuid,
					name => $name,
					host => $host,
					user => $user,
				};
			}
			elsif ($DBI::errstr =~ /Connection refused/)
			{
				$message_key = "log_0069";
				$variables   = { 
					name => $name,
					host => $host,
					port => $port,
				};
			}
			elsif ($DBI::errstr =~ /Temporary failure in name resolution/i)
			{
				$message_key = "log_0070";
				$variables   = { 
					name => $name,
					host => $host,
					port => $port,
				};
			}
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, priority => "alert", key => $message_key, variables => $variables });
		}
		elsif ($dbh =~ /^DBI::db=HASH/)
		{
			# Woot!
			$anvil->data->{sys}{database}{connections}++;
			push @{$successful_connections}, $uuid;
			$anvil->data->{cache}{database_handle}{$uuid} = $dbh;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "cache::database_handle::${uuid}" => $anvil->data->{cache}{database_handle}{$uuid} }});
			
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0071", variables => { 
				host => $host,
				port => $port,
				name => $name,
				uuid => $uuid,
			}});
			
			if (not $anvil->Database->read)
			{
				$anvil->Database->read({set => $dbh});
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 'anvil->Database->read' => $anvil->Database->read }});
			}
			
			# If the '$test_table' isn't the same as 'sys::database::test_table', see if the core schema needs loading first.
			if ($test_table ne $anvil->data->{sys}{database}{test_table})
			{
				my $query = "SELECT COUNT(*) FROM pg_catalog.pg_tables WHERE tablename=".$anvil->Database->quote($anvil->data->{defaults}{sql}{test_table})." AND schemaname='public';";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				
				my $count = $anvil->Database->query({uuid => $uuid, debug => $debug, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count => $count }});
				
				if ($count < 1)
				{
					### TODO: Create a version file/flag and don't sync with peers unless
					###       they are the same version. Back-port this to v2.
					# Need to load the database.
					$anvil->Database->initialize({debug => $debug, uuid => $uuid, sql_file => $anvil->data->{path}{sql}{'anvil.sql'}});
				}
			}
			
			# Now that I have connected, see if my 'hosts' table exists.
			my $query = "SELECT COUNT(*) FROM pg_catalog.pg_tables WHERE tablename=".$anvil->Database->quote($test_table)." AND schemaname='public';";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $count = $anvil->Database->query({uuid => $uuid, debug => $debug, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
			
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count => $count }});
			if ($count < 1)
			{
				# Need to load the database.
				$anvil->Database->initialize({debug => $debug, uuid => $uuid, sql_file => $sql_file});
			}
			
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"sys::database::read_uuid"        => $anvil->data->{sys}{database}{read_uuid}, 
				"cache::database_handle::${uuid}" => $anvil->data->{cache}{database_handle}{$uuid}, 
			}});
			
			# Set the first ID to be the one I read from later. Alternatively, if this host is 
			# local, use it.
			if (($host eq $anvil->_host_name)       or 
			    ($host eq $anvil->_short_host_name) or 
			    ($host eq "localhost")              or 
			    ($host eq "127.0.0.1")              or 
			    (not $anvil->data->{sys}{database}{read_uuid}))
			{
				$anvil->data->{sys}{database}{read_uuid}  = $uuid;
				$anvil->data->{sys}{database}{local_uuid} = $uuid;
				$anvil->Database->read({set => $anvil->data->{cache}{database_handle}{$uuid}});
				
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					"sys::database::read_uuid"  => $anvil->data->{sys}{database}{read_uuid}, 
					'anvil->Database->read'     => $anvil->Database->read(), 
				}});
			}
			
			# Get a time stamp for this run, if not yet gotten.
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"cache::database_handle::${uuid}" => $anvil->data->{cache}{database_handle}{$uuid}, 
				"sys::database::timestamp"        => $anvil->data->{sys}{database}{timestamp},
			}});
			
			# Pick a timestamp for this run, if we haven't yet.
			if (not $anvil->data->{sys}{database}{timestamp})
			{
				$anvil->Database->refresh_timestamp({debug => $debug});
			}
			
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"sys::database::read_uuid" => $anvil->data->{sys}{database}{read_uuid},
				'anvil->Database->read'    => $anvil->Database->read,
				"sys::database::timestamp" => $anvil->data->{sys}{database}{timestamp},
			}});
		}
	}
	
	my $total = tv_interval ($start_time, [gettimeofday]);
	#print "Total runtime: [".$total."]\n";
	
	# Do I have any connections? Don't die, if not, just return.
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::connections" => $anvil->data->{sys}{database}{connections} }});
	if (not $anvil->data->{sys}{database}{connections})
	{
		# Failed to connect to any database. Log this, print to the caller and return.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0091"});
		return($anvil->data->{sys}{database}{connections});
	}
	
	# Report any failed DB connections
	foreach my $uuid (@{$failed_connections})
	{
		my $database_name = defined $anvil->data->{database}{$uuid}{name} ? $anvil->data->{database}{$uuid}{name} : "#!string!log_0185!#";
		my $database_user = defined $anvil->data->{database}{$uuid}{user} ? $anvil->data->{database}{$uuid}{user} : "#!string!log_0185!#";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"database::${uuid}::host"     => $anvil->data->{database}{$uuid}{host},
			"database::${uuid}::port"     => $anvil->data->{database}{$uuid}{port},
			"database::${uuid}::name"     => $database_name,
			"database::${uuid}::user"     => $database_user, 
			"database::${uuid}::password" => $anvil->Log->is_secure($anvil->data->{database}{$uuid}{password}), 
		}});
		
		# Copy my alert hash before I delete the uuid.
		my $error_array = [];
		
		# Delete this DB so that we don't try to use it later. This is a quiet alert because the 
		# original connection error was likely logged.
		my $say_server = $anvil->data->{database}{$uuid}{host}.":".$anvil->data->{database}{$uuid}{port}." -> ".$database_name;
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, priority => "alert", key => "log_0092", variables => { server => $say_server, uuid => $uuid }});
		
		# Delete it from the list of known databases for this run.
		delete $anvil->data->{database}{$uuid};
		
		# If I've not sent an alert about this DB loss before, send one now.
		my $set = $anvil->Alert->check_alert_sent({
			debug          => $debug, 
			type           => "set",
			set_by         => $THIS_FILE,
			record_locator => $uuid,
			name           => "connect_to_db",
			modified_date  => $anvil->data->{sys}{database}{timestamp},
		});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { set => $set }});
		
		if ($set)
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { error_array => $error_array }});
			foreach my $hash (@{$error_array})
			{
				my $message_key       = $hash->{message_key};
				my $message_variables = $hash->{message_variables};
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					hash              => $hash, 
					message_key       => $message_key, 
					message_variables => $message_variables, 
				}});
				
				# These are warning level alerts.
				$anvil->Alert->register({
					debug                   => $debug, 
					alert_level             => "warning", 
					alert_set_by            => $THIS_FILE,
					alert_title_key         => "alert_title_0003",
					alert_message_key       => $message_key,
					alert_message_variables => $message_variables,
				});
			}
		}
	}
	
	# Send an 'all clear' message if a now-connected DB previously wasn't.
	foreach my $uuid (@{$successful_connections})
	{
		my $database_name = defined $anvil->data->{database}{$uuid}{name} ? $anvil->data->{database}{$uuid}{name} : "#!string!log_0185!#";
		my $database_user = defined $anvil->data->{database}{$uuid}{user} ? $anvil->data->{database}{$uuid}{user} : "#!string!log_0185!#";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"database::${uuid}::host"     => $anvil->data->{database}{$uuid}{host},
			"database::${uuid}::port"     => $anvil->data->{database}{$uuid}{port},
			"database::${uuid}::name"     => $database_name,
			"database::${uuid}::user"     => $database_user, 
			"database::${uuid}::password" => $anvil->Log->is_secure($anvil->data->{database}{$uuid}{password}), 
		}});
		
		### TODO: Is this still an issue? If so, then we either need to require that the DB host 
		###       matches the actual host name (dumb) or find another way of mapping the host name.
		# Query to see if the newly connected host is in the DB yet. If it isn't, don't send an
		# alert as it'd cause a duplicate UUID error.
# 		my $query = "SELECT COUNT(*) FROM hosts WHERE host_name = ".$anvil->Database->quote($anvil->data->{database}{$uuid}{host}).";";
# 		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
# 
# 		my $count = $anvil->Database->query({uuid => $uuid, debug => $debug, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
# 		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count => $count }});
# 		
# 		if ($count > 0)
# 		{
			my $cleared = $anvil->Alert->check_alert_sent({
				debug          => $debug, 
				type           => "clear",
				set_by         => $THIS_FILE,
				record_locator => $uuid,
				name           => "connect_to_db",
				modified_date  => $anvil->data->{sys}{database}{timestamp},
			});
			if ($cleared)
			{
				$anvil->Alert->register({
					debug             => $debug, 
					level             => "warning", 
					agent_name        => "Anvil!",
					title_key         => "an_title_0006",
					message_key       => "cleared_log_0055",
					message_variables => {
						name => $database_name,
						host => $anvil->data->{database}{$uuid}{host},
						port => defined $anvil->data->{database}{$uuid}{port} ? $anvil->data->{database}{$uuid}{port} : 5432,
					},
				});
			}
# 		}
	}
	
	# Make sure my host UUID is valud
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::host_uuid" => $anvil->data->{sys}{host_uuid} }});
	if ($anvil->data->{sys}{host_uuid} !~ /^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/)
	{
		# derp. bad UUID
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0103"});
		
		# Disconnect and set the connection count to '0'.
		$anvil->Database->disconnect({debug => $debug});
	}
	
	# For now, we just find which DBs are behind and let each agent deal with bringing their tables up to
	# date.
	if ($anvil->data->{sys}{database}{connections} > 1)
	{
		$anvil->Database->_find_behind_databases({
			debug  => $debug, 
			source => $source, 
			tables => $tables,
		});
	}
	
	# Hold if a lock has been requested.
	$anvil->Database->locking({debug => $debug});
	
	# Mark that we're not active.
	$anvil->Database->mark_active({debug => $debug, set => 1});
	
	# Sync the database, if needed.
	$anvil->Database->resync_databases({debug => 3});
	
	# Add ourselves to the database, if needed.
	$anvil->Database->insert_or_update_hosts({debug => $debug});
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::connections" => $anvil->data->{sys}{database}{connections} }});
	return($anvil->data->{sys}{database}{connections});
}


=head2

This cleanly closes any open file handles to all connected databases and clears some internal database related variables.

=cut
sub disconnect
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->disconnect()" }});
	
	my $marked_inactive = 0;
	foreach my $uuid (sort {$a cmp $b} keys %{$anvil->data->{database}})
	{
		# Don't do anything if there isn't an active file handle for this DB.
		next if ((not $anvil->data->{cache}{database_handle}{$uuid}) or ($anvil->data->{cache}{database_handle}{$uuid} !~ /^DBI::db=HASH/));
		
		# Clear locks and mark that we're done running.
		if (not $marked_inactive)
		{
			$anvil->Database->mark_active({set => 0});
			$anvil->Database->locking({release => 1});
			$marked_inactive = 1;
		}
		
		$anvil->data->{cache}{database_handle}{$uuid}->disconnect;
		delete $anvil->data->{cache}{database_handle}{$uuid};
	}
	
	# Delete the stored DB-related values.
	delete $anvil->data->{sys}{database}{timestamp};
	delete $anvil->data->{sys}{database}{read_uuid};
	$anvil->Database->read({set => "delete"});
	
	# Delete any database information (reconnects should re-read anvil.conf anyway).
	delete $anvil->data->{database};
	
	# Set the connection count to 0.
	$anvil->data->{sys}{database}{connections} = 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::connections" => $anvil->data->{sys}{database}{connections} }});
	
	return(0);
}


=head2 get_recipients

This returns a list of users listening to alerts for a given host, along with their alert level.

=cut
sub get_recipients
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->get_recipients()" }});
	
	my $host_uuid = defined $parameter->{host_uuid} ? $parameter->{host_uuid} : $anvil->Get->host_uuid;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		host_uuid => $host_uuid, 
	}});
	
	### TODO: Read in 'notifications' 
	my $query        = "
SELECT 
    recipient_uuid,
    recipient_name,
    recipient_email,
    recipient_language,
    recipient_units, 
    recipient_new_level 
FROM 
    recipients
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count, 
	}});
	foreach my $row (@{$results})
	{
		my $recipient_uuid      = $row->[0];
		my $recipient_name      = $row->[1];
		my $recipient_email     = $row->[2];
		my $recipient_language  = $row->[3];
		my $recipient_units     = $row->[4];
		my $recipient_new_level = $row->[5];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			recipient_uuid      => $recipient_uuid, 
			recipient_name      => $recipient_name, 
			recipient_email     => $recipient_email, 
			recipient_language  => $recipient_language, 
			recipient_units     => $recipient_units, 
			recipient_new_level => $recipient_new_level, 
		}});
		
		# Store the data
		$anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_name}      = $recipient_name;
		$anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_email}     = $recipient_email;
		$anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_language}  = $recipient_language;
		$anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_units}     = $recipient_units;
		$anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_new_level} = $recipient_new_level;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"recipients::recipient_uuid::${recipient_uuid}}::recipient_name"      => $anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_name}, 
			"recipients::recipient_uuid::${recipient_uuid}}::recipient_email"     => $anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_email}, 
			"recipients::recipient_uuid::${recipient_uuid}}::recipient_language"  => $anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_language}, 
			"recipients::recipient_uuid::${recipient_uuid}}::recipient_units"     => $anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_units}, 
			"recipients::recipient_uuid::${recipient_uuid}}::recipient_new_level" => $anvil->data->{recipients}{recipient_uuid}{$recipient_uuid}{recipient_new_level}, 
		}});
		
		# Make it easy to look up the mail server's UUID from the server address.
		$anvil->data->{recipients}{email_to_uuid}{$recipient_email} = $recipient_uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"recipients::email_to_uuid::${recipient_email}" => $anvil->data->{recipients}{email_to_uuid}{$recipient_email}, 
		}});
	}
	
	return(0);
}


=head2 get_fences

This loads the known fence devices into the C<< anvil::data >> hash at:

* fences::fence_uuid::<fence_uuid>::fence_name
* fences::fence_uuid::<fence_uuid>::fence_agent
* fences::fence_uuid::<fence_uuid>::fence_arguments
* fences::fence_uuid::<fence_uuid>::modified_date

And, to allow for lookup by name;

* fences::fence_name::<fence_name>::fence_uuid
* fences::fence_name::<fence_name>::fence_agent
* fences::fence_name::<fence_name>::fence_arguments
* fences::fence_name::<fence_name>::modified_date

If the hash was already populated, it is cleared before repopulating to ensure no stray data remains. 

B<<Note>>: Deleted devices (ones where C<< fence_arguments >> is set to C<< DELETED >>) are ignored. See the C<< include_deleted >> parameter to include them.

Parameters;

=head3 include_deleted (Optional, default 0)

If set to C<< 1 >>, deleted agents are included when loading the data. When C<< 0 >> is set, the default, any fence agent with C<< fence_arguments >> set to C<< DELETED >> is ignored.

=cut
sub get_fences
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->get_fences()" }});
	
	my $include_deleted = defined $parameter->{include_deleted} ? $parameter->{include_deleted} : 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		include_deleted => $include_deleted, 
	}});
	
	if (exists $anvil->data->{fences})
	{
		delete $anvil->data->{fences};
	}
	
	my $query = "
SELECT 
    fence_uuid, 
    fence_name, 
    fence_agent, 
    fence_arguments, 
    modified_date 
FROM 
    fences ";
	if (not $include_deleted)
	{
		$query .= "
WHERE 
    fence_arguments != 'DELETED'";
	}
	$query .= "
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count, 
	}});
	foreach my $row (@{$results})
	{
		my $fence_uuid      = $row->[0];
		my $fence_name      = $row->[1];
		my $fence_agent     = $row->[2];
		my $fence_arguments = $row->[3]; 
		my $modified_date   = $row->[4];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			fence_uuid      => $fence_uuid, 
			fence_name      => $fence_name, 
			fence_agent     => $fence_agent, 
			fence_arguments => $fence_arguments =~ /passw=/ ? $anvil->Log->is_secure($fence_arguments) : $fence_arguments, 
			modified_date   => $modified_date, 
		}});
		
		# Record the data in the hash, too.
		$anvil->data->{fences}{fence_uuid}{$fence_uuid}{fence_name}      = $fence_name;
		$anvil->data->{fences}{fence_uuid}{$fence_uuid}{fence_agent}     = $fence_agent;
		$anvil->data->{fences}{fence_uuid}{$fence_uuid}{fence_arguments} = $fence_arguments;
		$anvil->data->{fences}{fence_uuid}{$fence_uuid}{modified_date}   = $modified_date;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"fences::fence_uuid::${fence_uuid}::fence_name"      => $anvil->data->{fences}{fence_uuid}{$fence_uuid}{fence_name}, 
			"fences::fence_uuid::${fence_uuid}::fence_agent"     => $anvil->data->{fences}{fence_uuid}{$fence_uuid}{fence_agent}, 
			"fences::fence_uuid::${fence_uuid}::fence_arguments" => $anvil->data->{fences}{fence_uuid}{$fence_uuid}{fence_arguments} =~ /passw=/ ? $anvil->Log->is_secure($anvil->data->{fences}{fence_uuid}{$fence_uuid}{fence_arguments}) : $anvil->data->{fences}{fence_uuid}{$fence_uuid}{fence_arguments}, 
			"fences::fence_uuid::${fence_uuid}::modified_date"   => $anvil->data->{fences}{fence_uuid}{$fence_uuid}{modified_date}, 
		}});
		
		$anvil->data->{fences}{fence_name}{$fence_name}{fence_uuid}      = $fence_uuid;
		$anvil->data->{fences}{fence_name}{$fence_name}{fence_agent}     = $fence_agent;
		$anvil->data->{fences}{fence_name}{$fence_name}{fence_arguments} = $fence_arguments;
		$anvil->data->{fences}{fence_name}{$fence_name}{modified_date}   = $modified_date;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"fences::fence_name::${fence_name}::fence_uuid"      => $anvil->data->{fences}{fence_name}{$fence_name}{fence_uuid}, 
			"fences::fence_name::${fence_name}::fence_agent"     => $anvil->data->{fences}{fence_name}{$fence_name}{fence_agent}, 
			"fences::fence_name::${fence_name}::fence_arguments" => $anvil->data->{fences}{fence_name}{$fence_name}{fence_arguments} =~ /passw=/ ? $anvil->Log->is_secure($anvil->data->{fences}{fence_name}{$fence_name}{fence_arguments}) : $anvil->data->{fences}{fence_name}{$fence_name}{fence_arguments}, 
			"fences::fence_name::${fence_name}::modified_date"   => $anvil->data->{fences}{fence_name}{$fence_name}{modified_date}, 
		}});
	}

	return(0);
}


=head2 get_host_from_uuid

This takes a host UUID and returns the host's name. If there is a problem, or if the host UUID isn't found, an empty string is returned.

Parameters;

=head3 host_uuid (required)

This is the host UUID we're querying the name of.

=head3 short (optional, default '0')

If set to C<< 1 >>, the short host name is returned. When set to C<< 0 >>, the full host name is returned.

=cut
sub get_host_from_uuid
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->get_host_from_uuid()" }});
	
	my $host_name = "";
	my $host_uuid = defined $parameter->{host_uuid} ? $parameter->{host_uuid} : "";
	my $short     = defined $parameter->{short}     ? $parameter->{short}     : 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		host_uuid => $host_uuid, 
		short     => $short,
	}});
	
	if (not $host_uuid)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->get_host_from_uuid()", parameter => "host_uuid" }});
		return($host_name);
	}
	
	my $query = "SELECT host_name FROM hosts WHERE host_uuid = ".$anvil->Database->quote($host_uuid).";";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count, 
	}});
	if ($count)
	{
		$host_name = $results->[0]->[0];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_name => $host_name }});
		
		if ($short)
		{
			$host_name =~ s/\..*$//;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_name => $host_name }});
		}
	}
	
	return($host_name);
}


=head2 get_hosts

Get a list of hosts from the c<< hosts >> table, returned as an array of hash references.

Each anonymous hash is structured as:

 host_uuid     => $host_uuid, 
 host_name     => $host_name, 
 host_type     => $host_type, 
 modified_date => $modified_date, 

It also sets the variables C<< sys::hosts::by_uuid::<host_uuid> = <host_name> >> and C<< sys::hosts::by_name::<host_name> = <host_uuid> >> per host read, for quick reference.

=cut
sub get_hosts
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->get_hosts()" }});
	
	my $query = "
SELECT 
    host_uuid, 
    host_name, 
    host_type, 
    modified_date 
FROM 
    hosts
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	my $return  = [];
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count, 
	}});
	foreach my $row (@{$results})
	{
		my $host_uuid     = $row->[0];
		my $host_name     = $row->[1];
		my $host_type     = $row->[2];
		my $modified_date = $row->[3];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			host_uuid     => $host_uuid, 
			host_name     => $host_name, 
			host_type     => $host_type, 
			modified_date => $modified_date, 
		}});
		push @{$return}, {
			host_uuid     => $host_uuid,
			host_name     => $host_name, 
			host_type     => $host_type, 
			modified_date => $modified_date, 
		};
		
		# Record the data in the hash, too.
		$anvil->data->{hosts}{host_uuid}{$host_uuid}{host_name} = $host_name;
		$anvil->data->{hosts}{host_uuid}{$host_uuid}{host_type} = $host_type;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"hosts::host_uuid::${host_uuid}::host_name" => $anvil->data->{hosts}{host_uuid}{$host_uuid}{host_name}, 
			"hosts::host_uuid::${host_uuid}::host_type" => $anvil->data->{hosts}{host_uuid}{$host_uuid}{host_type}, 
		}});
		
		# Record the host_uuid in a hash so that the name can be easily retrieved.
		$anvil->data->{sys}{hosts}{by_uuid}{$host_uuid} = $host_name;
		$anvil->data->{sys}{hosts}{by_name}{$host_name} = $host_uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"sys::hosts::by_uuid::${host_uuid}" => $anvil->data->{sys}{hosts}{by_uuid}{$host_uuid}, 
			"sys::hosts::by_name::${host_name}" => $anvil->data->{sys}{hosts}{by_name}{$host_name}, 
		}});
	}
	
	my $return_count = @{$return};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { return_count => $return_count }});
	return($return);
}


=head2 get_hosts_info

This gathers up all the known information about all known hosts.

=cut
sub get_hosts_info
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->get_hosts()" }});
	
	my $query = "
SELECT 
    host_uuid, 
    host_name, 
    host_type, 
    host_key 
FROM 
    hosts
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count, 
	}});
	foreach my $row (@{$results})
	{
		my $host_uuid = $row->[0];
		my $host_name = $row->[1];
		my $host_type = $row->[2];
		my $host_key  = $row->[3];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			host_uuid => $host_uuid, 
			host_name => $host_name, 
			host_type => $host_type, 
			host_key  => $host_key, 
		}});
		$anvil->data->{machine}{host_uuid}{$host_uuid}{hosts}{host_name} = $host_name;
		$anvil->data->{machine}{host_uuid}{$host_uuid}{hosts}{host_type} = $host_type;
		$anvil->data->{machine}{host_uuid}{$host_uuid}{hosts}{host_key}  = $host_key;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"machine::host_uuid::${host_uuid}::hosts::host_name" => $anvil->data->{machine}{host_uuid}{$host_uuid}{hosts}{host_name}, 
			"machine::host_uuid::${host_uuid}::hosts::host_type" => $anvil->data->{machine}{host_uuid}{$host_uuid}{hosts}{host_type}, 
			"machine::host_uuid::${host_uuid}::hosts::host_key"  => $anvil->data->{machine}{host_uuid}{$host_uuid}{hosts}{host_key}, 
		}});
		
		# Read in the variables.
		my $query = "
SELECT 
    variable_name, 
    variable_value 
FROM 
    variables 
WHERE 
    variable_source_uuid  = ".$anvil->Database->quote($host_uuid)." 
AND 
    variable_source_table = 'hosts'
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		foreach my $row (@{$results})
		{
			my $variable_name  = $row->[0];
			my $variable_value = $row->[1];
			$anvil->data->{machine}{host_uuid}{$host_uuid}{variables}{$variable_name} = $variable_value;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"machine::host_uuid::${host_uuid}::hosts::variables::${variable_name}"  => $anvil->data->{machine}{host_uuid}{$host_uuid}{variables}{$variable_name}, 
			}});
		}
		
		# Read in the IP addresses and network information.
		
	}
	
	return(0);
}


=head2 get_job_details

This gets the details for a given job. If the job is found, a hash reference is returned containing the tables that were read in.

Parameters;

=head3 job_uuid (default switches::job-uuid)

This is the C<< job_uuid >> of the job being retrieved. 

=cut
sub get_job_details
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	
	my $return   = "";
	my $job_uuid = defined $parameter->{job_uuid} ? $parameter->{job_uuid} : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		job_uuid => $job_uuid, 
	}});
	
	# If we didn't get a job_uuid, see if 'swtiches::job-uuid' is set.
	if ((not $job_uuid) && ($anvil->data->{switches}{'job-uuid'}))
	{
		$job_uuid = $anvil->data->{switches}{'job-uuid'};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { job_uuid => $job_uuid }});
	}
	
	if (not $job_uuid)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->get_job_details()", parameter => "job_uuid" }});
		return($return);
	}
	
	my $query = "
SELECT 
    job_host_uuid, 
    job_command, 
    job_data, 
    job_picked_up_by, 
    job_picked_up_at, 
    job_updated, 
    job_name, 
    job_progress, 
    job_title, 
    job_description, 
    job_status, 
    modified_date
FROM 
    jobs 
WHERE 
    job_uuid = ".$anvil->Database->quote($job_uuid)."
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count,
	}});
	if (not $count)
	{
		# Job wasn't found.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0438", variables => { job_uuid => $job_uuid }});
		return($return);
	}
	
	my $job_host_uuid       =         $results->[0]->[0];
	my $job_command         =         $results->[0]->[1];
	my $job_data            = defined $results->[0]->[2] ? $results->[0]->[2] : "";
	my $job_picked_up_by    =         $results->[0]->[3];
	my $job_picked_up_at    =         $results->[0]->[4]; 
	my $job_updated         =         $results->[0]->[5];
	my $job_name            =         $results->[0]->[6];
	my $job_progress        =         $results->[0]->[7];
	my $job_title           =         $results->[0]->[8];
	my $job_description     =         $results->[0]->[9];
	my $job_status          =         $results->[0]->[10];
	my $modified_date       =         $results->[0]->[11];
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		job_host_uuid       => $job_host_uuid,
		job_command         => $job_command,
		job_data            => $job_data,
		job_picked_up_by    => $job_picked_up_by,
		job_picked_up_at    => $job_picked_up_at,
		job_updated         => $job_updated,
		job_name            => $job_name, 
		job_progress        => $job_progress,
		job_title           => $job_title, 
		job_description     => $job_description,
		job_status          => $job_status, 
		modified_date       => $modified_date, 
	}});
	
	$return = {
		job_host_uuid       => $job_host_uuid,
		job_command         => $job_command,
		job_data            => $job_data,
		job_picked_up_by    => $job_picked_up_by,
		job_picked_up_at    => $job_picked_up_at,
		job_updated         => $job_updated,
		job_name            => $job_name, 
		job_progress        => $job_progress,
		job_title           => $job_title, 
		job_description     => $job_description,
		job_status          => $job_status, 
		modified_date       => $modified_date, 
	};
	
	return($return);
}


=head2 get_jobs

This gets the list of running jobs.

Parameters;

=head3 ended_within (optional, default 300)

Jobs that reached 100% within this number of seconds ago will be included. If this is set to C<< 0 >>, only in-progress and not-yet-picked-up jobs will be included.

=head3 job_host_uuid (default $anvil->Get->host_uuid)

This is the host that we're getting a list of jobs from.

=cut
sub get_jobs
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	
	my $return        = [];
	my $ended_within  = defined $parameter->{ended_within}  ? $parameter->{ended_within}  : 300;
	my $job_host_uuid = defined $parameter->{job_host_uuid} ? $parameter->{job_host_uuid} : $anvil->Get->host_uuid;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		ended_within  => $ended_within, 
		job_host_uuid => $job_host_uuid, 
	}});
	
	my $query = "
SELECT 
    job_uuid, 
    job_command, 
    job_data, 
    job_picked_up_by, 
    job_picked_up_at, 
    job_updated, 
    job_name, 
    job_progress, 
    job_title, 
    job_description, 
    job_status, 
    modified_date
FROM 
    jobs 
WHERE 
    job_host_uuid = ".$anvil->Database->quote($job_host_uuid)."
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count,
	}});
	foreach my $row (@{$results})
	{
		my $job_uuid            =         $row->[0];
		my $job_command         =         $row->[1];
		my $job_data            = defined $row->[2] ? $row->[2] : "";
		my $job_picked_up_by    =         $row->[3];
		my $job_picked_up_at    =         $row->[4]; 
		my $job_updated         =         $row->[5];
		my $job_name            =         $row->[6];
		my $job_progress        =         $row->[7];
		my $job_title           =         $row->[8];
		my $job_description     =         $row->[9];
		my $job_status          =         $row->[10];
		my $modified_date       =         $row->[11];
		my $now_time            = time;
		my $started_seconds_ago = $job_picked_up_at ? ($now_time - $job_picked_up_at) : 0;
		my $updated_seconds_ago = $job_updated      ? ($now_time - $job_updated)      : 0;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			job_uuid            => $job_uuid,
			job_command         => $job_command,
			job_data            => $job_data,
			job_picked_up_by    => $job_picked_up_by,
			job_picked_up_at    => $job_picked_up_at,
			job_updated         => $job_updated,
			job_name            => $job_name, 
			job_progress        => $job_progress,
			job_title           => $job_title, 
			job_description     => $job_description,
			job_status          => $job_status, 
			modified_date       => $modified_date, 
			now_time            => $now_time, 
			started_seconds_ago => $started_seconds_ago, 
			updated_seconds_ago => $updated_seconds_ago, 
		}});
		
		# If the job is done, see if it was recently enough to care about it.
		if (($job_progress eq "100") && (($updated_seconds_ago == 0) or ($updated_seconds_ago > $ended_within)))
		{
			# Skip it
			next;
		}
		
		push @{$return}, {
			job_uuid            => $job_uuid,
			job_command         => $job_command,
			job_data            => $job_data,
			job_picked_up_by    => $job_picked_up_by,
			job_picked_up_at    => $job_picked_up_at,
			job_updated         => $job_updated,
			job_name            => $job_name, 
			job_progress        => $job_progress,
			job_title           => $job_title, 
			job_description     => $job_description,
			job_status          => $job_status, 
			modified_date       => $modified_date, 
		};
	}
	
	my $return_count = @{$return};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { return_count => $return_count }});
	
	if ($return_count)
	{
		foreach my $hash_ref (@{$return})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				job_uuid         => $hash_ref->{job_uuid},
				job_command      => $hash_ref->{job_command},
				job_data         => $hash_ref->{job_data},
				job_picked_up_by => $hash_ref->{job_picked_up_by},
				job_picked_up_at => $hash_ref->{job_picked_up_at},
				job_updated      => $hash_ref->{job_updated},
				job_name         => $hash_ref->{job_name}, 
				job_progress     => $hash_ref->{job_progress},
				job_title        => $hash_ref->{job_title}, 
				job_description  => $hash_ref->{job_description},
				job_status       => $hash_ref->{job_status}, 
				modified_date    => $hash_ref->{modified_date}, 
			}});
		}
	}
	
	return($return);
}


=head2 get_local_uuid

This returns the database UUID (usually the host's UUID) from C<< anvil.conf >> based on matching the C<< database::<uuid>::host >> to the local machine's host name or one of the active IP addresses on the host.

NOTE: This returns nothing if the local machine is not found as a configured database in C<< anvil.conf >>. This is a good way to check if the system has been setup yet.

 # Get the local UUID
 my $local_uuid = $anvil->Database->get_local_uuid;

=cut
sub get_local_uuid
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->get_local_uuid()" }});
	
	my $local_uuid = "";
	foreach my $uuid (sort {$a cmp $b} keys %{$anvil->data->{database}})
	{
		my $db_host = $anvil->data->{database}{$uuid}{host};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { db_host => $db_host }});
		
		# If the uuid matches our host_uuid or if the host name matches ours (or is localhost), return
		# that UUID.
		if ($uuid eq $anvil->Get->host_uuid)
		{
			$local_uuid = $uuid;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { local_uuid => $local_uuid }});
			last;
		}
		elsif ($anvil->Network->is_local({host => $db_host}))
		{
			$local_uuid = $uuid;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { local_uuid => $local_uuid }});
			last;
		}
	}
	
	# Get out IPs.
	$anvil->Network->get_ips({debug => $debug});
	
	# Look for matches
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { local_uuid => $local_uuid }});
	if (not $local_uuid)
	{
		foreach my $interface (sort {$a cmp $b} keys %{$anvil->data->{network}{'local'}{interface}})
		{
			my $ip_address  = $anvil->data->{network}{'local'}{interface}{$interface}{ip};
			my $subnet_mask = $anvil->data->{network}{'local'}{interface}{$interface}{subnet_mask};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				ip_address  => $ip_address,
				subnet_mask => $subnet_mask,
			}});
			foreach my $uuid (sort {$a cmp $b} keys %{$anvil->data->{database}})
			{
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					ip_address                => $ip_address,
					"database::${uuid}::host" => $anvil->data->{database}{$uuid}{host},
				}});
				if ($ip_address eq $anvil->data->{database}{$uuid}{host})
				{
					$local_uuid = $uuid;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { local_uuid => $local_uuid }});
					last;
				}
			}
		}
	}
	
	return($local_uuid);
}


=head2 get_mail_servers

This gets the list of configured mail servers.

=cut
sub get_mail_servers
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->initialize()" }});
	
	my $query = "
SELECT 
    mail_server_uuid, 
    mail_server_address, 
    mail_server_port, 
    mail_server_username, 
    mail_server_password, 
    mail_server_security, 
    mail_server_authentication, 
    mail_server_helo_domain 
FROM 
    mail_servers
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count, 
	}});
	foreach my $row (@{$results})
	{
		my $mail_server_uuid           = $row->[0]; 
		my $mail_server_address        = $row->[1]; 
		my $mail_server_port           = $row->[2]; 
		my $mail_server_username       = $row->[3]; 
		my $mail_server_password       = $row->[4]; 
		my $mail_server_security       = $row->[5]; 
		my $mail_server_authentication = $row->[6]; 
		my $mail_server_helo_domain    = $row->[7]; 
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			mail_server_uuid           => $mail_server_uuid, 
			mail_server_address        => $mail_server_address, 
			mail_server_port           => $mail_server_port, 
			mail_server_username       => $mail_server_username, 
			mail_server_password       => $mail_server_password, 
			mail_server_security       => $mail_server_security,  
			mail_server_authentication => $mail_server_authentication, 
			mail_server_helo_domain    => $mail_server_helo_domain,
		}});
		
		# Store the data
		$anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_address}        = $mail_server_address;
		$anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_port}           = $mail_server_port;
		$anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_username}       = $mail_server_username;
		$anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_password}       = $mail_server_password;
		$anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_security}       = $mail_server_security;
		$anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_authentication} = $mail_server_authentication;
		$anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_helo_domain}    = $mail_server_helo_domain;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"mail_servers::mail_server::${mail_server_uuid}}::mail_server_address"        => $anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_address}, 
			"mail_servers::mail_server::${mail_server_uuid}}::mail_server_port"           => $anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_port}, 
			"mail_servers::mail_server::${mail_server_uuid}}::mail_server_username"       => $anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_username}, 
			"mail_servers::mail_server::${mail_server_uuid}}::mail_server_password"       => $anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_password}, 
			"mail_servers::mail_server::${mail_server_uuid}}::mail_server_security"       => $anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_security}, 
			"mail_servers::mail_server::${mail_server_uuid}}::mail_server_authentication" => $anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_authentication}, 
			"mail_servers::mail_server::${mail_server_uuid}}::mail_server_helo_domain"    => $anvil->data->{mail_servers}{mail_server}{$mail_server_uuid}{mail_server_helo_domain}, 
		}});
		
		# Make it easy to look up the mail server's UUID from the server address.
		$anvil->data->{mail_servers}{address_to_uuid}{$mail_server_address} = $mail_server_uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"mail_servers::address_to_uuid::${mail_server_address}" => $anvil->data->{mail_servers}{address_to_uuid}{$mail_server_address}, 
		}});
		
		### TODO;
		# Look up variables for this server.
=cut
		my $query = "
SELECT 
    variable_name, 
    variable_value 
FROM 
    variables 
WHERE 
    variable_source_uuid  = ".$anvil->Database->quote($host_uuid)." 
AND 
    variable_source_table = 'hosts'
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		foreach my $row (@{$results})
		{
			my $variable_name  = $row->[0];
			my $variable_value = $row->[1];
			$anvil->data->{machine}{host_uuid}{$host_uuid}{variables}{$variable_name} = $variable_value;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"machine::host_uuid::${host_uuid}::hosts::variables::${variable_name}"  => $anvil->data->{machine}{host_uuid}{$host_uuid}{variables}{$variable_name}, 
			}});
		}
=cut
	}
	
	return(0);
}


=head2 get_notifications

This gets the list of configured mail servers.

=cut
sub get_notifications
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->initialize()" }});
	
	my $query = "
SELECT 
    notification_uuid, 
    notification_recipient_uuid, 
    notification_host_uuid, 
    notification_alert_level
FROM 
    notifications
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count, 
	}});
	foreach my $row (@{$results})
	{
		my $notification_uuid           = $row->[0];
		my $notification_recipient_uuid = $row->[1];
		my $notification_host_uuid      = $row->[2];
		my $notification_alert_level    = $row->[3];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			notification_uuid           => $notification_uuid, 
			notification_recipient_uuid => $notification_recipient_uuid, 
			notification_host_uuid      => $notification_host_uuid, 
			notification_alert_level    => $notification_alert_level,
		}});
		
		# Store the data
		$anvil->data->{notifications}{notification_uuid}{$notification_uuid}{notification_recipient_uuid} = $notification_recipient_uuid;
		$anvil->data->{notifications}{notification_uuid}{$notification_uuid}{notification_host_uuid}      = $notification_host_uuid;
		$anvil->data->{notifications}{notification_uuid}{$notification_uuid}{notification_alert_level}    = $notification_alert_level;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"notifications::notification_uuid::${notification_uuid}::notification_recipient_uuid" => $anvil->data->{notifications}{notification_uuid}{$notification_uuid}{notification_recipient_uuid}, 
			"notifications::notification_uuid::${notification_uuid}::notification_host_uuid"      => $anvil->data->{notifications}{notification_uuid}{$notification_uuid}{notification_host_uuid}, 
			"notifications::notification_uuid::${notification_uuid}::notification_alert_level"    => $anvil->data->{notifications}{notification_uuid}{$notification_uuid}{notification_alert_level}, 
		}});
	}
	
	return(0);
}


=head2 get_upses

This loads the known UPSes (uninterruptible power supplies) into the C<< anvil::data >> hash at:

* upses::ups_uuid::<ups_uuid>::ups_name
* upses::ups_uuid::<ups_uuid>::ups_agent
* upses::ups_uuid::<ups_uuid>::ups_ip_address
* upses::ups_uuid::<ups_uuid>::modified_date

And, to allow for lookup by name;

* upses::ups_name::<ups_name>::ups_uuid
* upses::ups_name::<ups_name>::ups_agent
* upses::ups_name::<ups_name>::ups_ip_address
* upses::ups_name::<ups_name>::modified_date

If the hash was already populated, it is cleared before repopulating to ensure no stray data remains. 

B<<Note>>: Deleted devices (ones where C<< ups_ip_address >> is set to C<< DELETED >>) are ignored. See the C<< include_deleted >> parameter to include them.

Parameters;

=head3 include_deleted (Optional, default 0)

If set to C<< 1 >>, deleted agents are included when loading the data. When C<< 0 >> is set, the default, any ups agent with C<< ups_ip_address >> set to C<< DELETED >> is ignored.

=cut
sub get_upses
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->get_host_from_uuid()" }});
	
	my $include_deleted = defined $parameter->{include_deleted} ? $parameter->{include_deleted} : 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		include_deleted => $include_deleted, 
	}});
	
	if (exists $anvil->data->{upses})
	{
		delete $anvil->data->{upses};
	}
	
	my $query = "
SELECT 
    ups_uuid, 
    ups_name, 
    ups_agent, 
    ups_ip_address, 
    modified_date 
FROM 
    upses ";
	if (not $include_deleted)
	{
		$query .= "
WHERE 
    ups_ip_address != 'DELETED'";
	}
	$query .= "
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count, 
	}});
	foreach my $row (@{$results})
	{
		my $ups_uuid       = $row->[0];
		my $ups_name       = $row->[1];
		my $ups_agent      = $row->[2];
		my $ups_ip_address = $row->[3]; 
		my $modified_date  = $row->[4];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			ups_uuid       => $ups_uuid, 
			ups_name       => $ups_name, 
			ups_agent      => $ups_agent, 
			ups_ip_address => $ups_ip_address, 
			modified_date  => $modified_date, 
		}});
		
		# Record the data in the hash, too.
		$anvil->data->{upses}{ups_uuid}{$ups_uuid}{ups_name}       = $ups_name;
		$anvil->data->{upses}{ups_uuid}{$ups_uuid}{ups_agent}      = $ups_agent;
		$anvil->data->{upses}{ups_uuid}{$ups_uuid}{ups_ip_address} = $ups_ip_address;
		$anvil->data->{upses}{ups_uuid}{$ups_uuid}{modified_date}  = $modified_date;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"upses::ups_uuid::${ups_uuid}::ups_name"       => $anvil->data->{upses}{ups_uuid}{$ups_uuid}{ups_name}, 
			"upses::ups_uuid::${ups_uuid}::ups_agent"      => $anvil->data->{upses}{ups_uuid}{$ups_uuid}{ups_agent}, 
			"upses::ups_uuid::${ups_uuid}::ups_ip_address" => $anvil->data->{upses}{ups_uuid}{$ups_uuid}{ups_ip_address}, 
			"upses::ups_uuid::${ups_uuid}::modified_date"  => $anvil->data->{upses}{ups_uuid}{$ups_uuid}{modified_date}, 
		}});
		
		$anvil->data->{upses}{ups_name}{$ups_name}{ups_uuid}       = $ups_uuid;
		$anvil->data->{upses}{ups_name}{$ups_name}{ups_agent}      = $ups_agent;
		$anvil->data->{upses}{ups_name}{$ups_name}{ups_ip_address} = $ups_ip_address;
		$anvil->data->{upses}{ups_name}{$ups_name}{modified_date}  = $modified_date;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"upses::ups_name::${ups_name}::ups_uuid"       => $anvil->data->{upses}{ups_name}{$ups_name}{ups_uuid}, 
			"upses::ups_name::${ups_name}::ups_agent"      => $anvil->data->{upses}{ups_name}{$ups_name}{ups_agent}, 
			"upses::ups_name::${ups_name}::ups_ip_address" => $anvil->data->{upses}{ups_name}{$ups_name}{ups_ip_address}, 
			"upses::ups_name::${ups_name}::modified_date"  => $anvil->data->{upses}{ups_name}{$ups_name}{modified_date}, 
		}});
	}

	return(0);
}


=head2 initialize

This will initialize a database using a given file.

Parameters;

=head3 sql_file (required)

This is the full (or relative) path and file nane to use when initializing the database. 

=cut
sub initialize
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->initialize()" }});
	
	my $uuid     = $anvil->Get->host_uuid;
	my $sql_file = $parameter->{sql_file} ? $parameter->{sql_file} : $anvil->data->{path}{sql}{'anvil.sql'};
	my $success  = 1;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid     => $uuid, 
		sql_file => $sql_file, 
	}});
	
	# This just makes some logging cleaner below.
	my $database_name = defined $anvil->data->{database}{$uuid}{name} ? $anvil->data->{database}{$uuid}{name} : $anvil->data->{sys}{database}{name};
	my $say_server    = $anvil->data->{database}{$uuid}{host}.":".$anvil->data->{database}{$uuid}{port}." -> ".$database_name;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { say_server => $say_server }});
	
	if (not defined $anvil->data->{cache}{database_handle}{$uuid})
	{
		# Database handle is gone.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0078", variables => { uuid => $uuid }});
		return(0);
	}
	if (not $sql_file)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0079", variables => { 
			server => $say_server,
			uuid   => $uuid, 
		}});
		return(0);
	}
	elsif (not -e $sql_file)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0080", variables => { 
			server   => $say_server,
			uuid     => $uuid, 
			sql_file => $sql_file, 
		}});
		return(0);
	}
	elsif (not -r $sql_file)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0081", variables => { 
			server   => $say_server,
			uuid     => $uuid, 
			sql_file => $sql_file, 
		}});
		return(0);
	}
	
	# Tell the user we need to initialize
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0082", variables => { 
		server   => $say_server,
		uuid     => $uuid, 
		sql_file => $sql_file, 
	}});
	
	# Read in the SQL file and replace #!variable!name!# with the database owner name.
	my $user = $anvil->data->{database}{$uuid}{user} ? $anvil->data->{database}{$uuid}{user} : $anvil->data->{sys}{database}{user};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { user => $user }});
	
	my $sql = $anvil->Storage->read_file({file => $sql_file});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { sql => $sql }});
	
	# In the off chance that the database user isn't 'admin', update the SQL file.
	if ($user ne "admin")
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0253", variables => { database_user => $user }});
		my $new_file = "";
		foreach my $line (split/\n/, $sql)
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { line => $line }});
			if ($line =~ /OWNER TO admin;/)
			{
				$line =~ s/ admin;/ $user;/;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "<< line" => $line }});
			}
			$new_file .= $line."\n";
		}
		$sql = $new_file;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "<< sql" => $sql }});
	}
	
	# Now that I am ready, disable autocommit, write and commit.
	$anvil->Database->write({
		debug  => 2,
		uuid   => $uuid, 
		query  => $sql, 
		source => $THIS_FILE, 
		line   => __LINE__,
	});
	
	$anvil->data->{sys}{db_initialized}{$uuid} = 1;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { "sys::db_initialized::${uuid}" => $anvil->data->{sys}{db_initialized}{$uuid} }});
	
	# Mark that we need to update the DB.
	$anvil->data->{sys}{database}{resync_needed} = 1;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { "sys::database::resync_needed" => $anvil->data->{sys}{database}{resync_needed} }});
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { success => $success }});
	return($success);
};


=head2 insert_or_update_anvils
=cut
sub insert_or_update_anvils
{
}


=head2 insert_or_update_bridges

This updates (or inserts) a record in the 'bridges' table. The C<< bridge_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 bridge_uuid (optional)

If not passed, a check will be made to see if an existing entry is found for C<< bridge_name >>. If found, that entry will be updated. If not found, a new record will be inserted.

=head3 bridge_host_uuid (optional)

This is the host that the IP address is on. If not passed, the local C<< sys::host_uuid >> will be used (indicating it is a local IP address).

=head3 bridge_name (required)

This is the bridge's device name.

=head3 bridge_id (optional)

This is the unique identifier for the bridge.

=head3 bridge_mac_address (optional)

This is the MAC address of the bridge.

=head3 bridge_mto (optional)

This is the MTU (maximum transfer unit, size in bytes) of the bridge.

=head3 bridge_stp_enabled (optional)

This is set to C<< yes >> or C<< no >> to indicate if spanning tree protocol is enabled on the switch.

=head3 delete (optional, default '0')

If set to C<< 1 >>, C<< bridge_id >> will be set to C<< DELETED >>, indicating that the bridge has been deleted from the system. If set, only C<< bridge_uuid >> or C<< bridge_name >> is needed.

=cut
sub insert_or_update_bridges
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_bridges()" }});
	
	my $uuid               = defined $parameter->{uuid}               ? $parameter->{uuid}               : "";
	my $file               = defined $parameter->{file}               ? $parameter->{file}               : "";
	my $line               = defined $parameter->{line}               ? $parameter->{line}               : "";
	my $delete             = defined $parameter->{'delete'}           ? $parameter->{'delete'}           : "";
	my $bridge_uuid        = defined $parameter->{bridge_uuid}        ? $parameter->{bridge_uuid}        : "";
	my $bridge_host_uuid   = defined $parameter->{bridge_host_uuid}   ? $parameter->{bridge_host_uuid}   : $anvil->data->{sys}{host_uuid};
	my $bridge_name        = defined $parameter->{bridge_name}        ? $parameter->{bridge_name}        : "";
	my $bridge_id          = defined $parameter->{bridge_id}          ? $parameter->{bridge_id}          : "";
	my $bridge_mac_address = defined $parameter->{bridge_mac_address} ? $parameter->{bridge_mac_address} : "";
	my $bridge_mtu         = defined $parameter->{bridge_mtu}         ? $parameter->{bridge_mtu}         : "";
	my $bridge_stp_enabled = defined $parameter->{bridge_stp_enabled} ? $parameter->{bridge_stp_enabled} : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid               => $uuid, 
		file               => $file, 
		line               => $line, 
		'delete'           => $delete, 
		bridge_uuid        => $bridge_uuid, 
		bridge_host_uuid   => $bridge_host_uuid, 
		bridge_name        => $bridge_name, 
		bridge_id          => $bridge_id, 
		bridge_mac_address => $bridge_mac_address, 
		bridge_mtu         => $bridge_mtu, 
		bridge_stp_enabled => $bridge_stp_enabled, 
	}});
	
	if (not $delete)
	{
		if (not $bridge_name)
		{
			# Throw an error and exit.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_bridges()", parameter => "bridge_name" }});
			return("");
		}
	}
	
	# If we don't have a UUID, see if we can find one for the given bridge server name.
	if (not $bridge_uuid)
	{
		my $query = "
SELECT 
    bridge_uuid 
FROM 
    bridges 
WHERE 
    bridge_name      = ".$anvil->Database->quote($bridge_name)." 
AND 
    bridge_host_uuid = ".$anvil->Database->quote($bridge_host_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$bridge_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { bridge_uuid => $bridge_uuid }});
		}
	}
	
	if ($delete)
	{
		if (not $bridge_uuid)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_bridges()", parameter => "bridge_uuid" }});
			return("");
		}
		else
		{
			# Delete it
			my $query = "SELECT bridge_id FROM bridges WHERE bridge_uuid = ".$anvil->Database->quote($bridge_uuid).";";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count, 
			}});
			if ($count)
			{
				my $old_bridge_id = $results->[0]->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { old_bridge_id => $old_bridge_id }});
				
				if ($old_bridge_id ne "DELETED")
				{
					my $query = "
UPDATE 
    bridges 
SET 
    bridge_id      = 'DELETED', 
    modified_date  = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE 
    bridge_uuid    = ".$anvil->Database->quote($bridge_uuid)."
;";
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
				return($bridge_uuid);
			}
			else
			{
				# Not found.
				return("");
			}
		}
	}
	
	# If I still don't have an bridge_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { bridge_uuid => $bridge_uuid }});
	if (not $bridge_uuid)
	{
		# It's possible that this is called before the host is recorded in the database. So to be
		# safe, we'll return without doing anything if there is no host_uuid in the database.
		my $hosts = $anvil->Database->get_hosts();
		my $found = 0;
		foreach my $hash_ref (@{$hosts})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"hash_ref->{host_uuid}" => $hash_ref->{host_uuid}, 
				"sys::host_uuid"        => $anvil->data->{sys}{host_uuid}, 
			}});
			if ($hash_ref->{host_uuid} eq $anvil->data->{sys}{host_uuid})
			{
				$found = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { found => $found }});
			}
		}
		if (not $found)
		{
			# We're out.
			return("");
		}
		
		# INSERT
		$bridge_uuid = $anvil->Get->uuid();
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { bridge_uuid => $bridge_uuid }});
		
		my $query = "
INSERT INTO 
    bridges 
(
    bridge_uuid, 
    bridge_host_uuid, 
    bridge_name, 
    bridge_id, 
    bridge_mac_address, 
    bridge_mtu, 
    bridge_stp_enabled, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($bridge_uuid).", 
    ".$anvil->Database->quote($bridge_host_uuid).", 
    ".$anvil->Database->quote($bridge_name).", 
    ".$anvil->Database->quote($bridge_id).", 
    ".$anvil->Database->quote($bridge_mac_address).", 
    ".$anvil->Database->quote($bridge_mtu).", 
    ".$anvil->Database->quote($bridge_stp_enabled).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    bridge_host_uuid, 
    bridge_name, 
    bridge_id, 
    bridge_mac_address, 
    bridge_mtu, 
    bridge_stp_enabled 
FROM 
    bridges 
WHERE 
    bridge_uuid = ".$anvil->Database->quote($bridge_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a bridge_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "bridge_uuid", uuid => $bridge_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_bridge_host_uuid   = $row->[0];
			my $old_bridge_name        = $row->[1];
			my $old_bridge_id          = $row->[2];
			my $old_bridge_mac_address = $row->[3];
			my $old_bridge_mtu         = $row->[4];
			my $old_bridge_stp_enabled = $row->[5];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_bridge_host_uuid   => $old_bridge_host_uuid, 
				old_bridge_name        => $old_bridge_name, 
				old_bridge_id          => $old_bridge_id,
				old_bridge_mac_address => $old_bridge_mac_address, 
				old_bridge_mtu         => $old_bridge_mtu,  
				old_bridge_stp_enabled => $old_bridge_stp_enabled,  
			}});
			
			# Anything change?
			if (($old_bridge_host_uuid   ne $bridge_host_uuid)   or 
			    ($old_bridge_name        ne $bridge_name)        or 
			    ($old_bridge_id          ne $bridge_id)          or 
			    ($old_bridge_mac_address ne $bridge_mac_address) or 
			    ($old_bridge_mtu         ne $bridge_mtu)         or 
			    ($old_bridge_stp_enabled ne $bridge_stp_enabled))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    bridges 
SET 
    bridge_host_uuid   = ".$anvil->Database->quote($bridge_host_uuid).",  
    bridge_name        = ".$anvil->Database->quote($bridge_name).", 
    bridge_id          = ".$anvil->Database->quote($bridge_id).", 
    bridge_mac_address = ".$anvil->Database->quote($bridge_mac_address).", 
    bridge_mtu         = ".$anvil->Database->quote($bridge_mtu).", 
    bridge_stp_enabled = ".$anvil->Database->quote($bridge_stp_enabled).", 
    modified_date      = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    bridge_uuid        = ".$anvil->Database->quote($bridge_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	return($bridge_uuid);
}


=head2 insert_or_update_bonds

This updates (or inserts) a record in the 'bonds' table. The C<< bond_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 delete (optional, default '0')

If set to C<< 1 >>, C<< bond_operational >> gets set to C<< DELETED >>. In this case, either C<< bond_uuid >> or C<< bond_name >> is required, and nothing else is.

=head3 bond_uuid (optional)

If not passed, a check will be made to see if an existing entry is found for C<< bond_name >>. If found, that entry will be updated. If not found, a new record will be inserted.

=head3 bond_host_uuid (optional)

This is the host that the IP address is on. If not passed, the local C<< sys::host_uuid >> will be used (indicating it is a local IP address).

=head3 bond_name (required)

This is the bond's device name.

=head3 bond_mode (required)

This is the bonding mode used for this bond. 

=head3 bond_mtu (optional)

This is the MTU for the bonded interface.

=head3 bond_operational (optional)

This is set to C<< up >>, C<< down >> or C<< unknown >>. It indicates whether the bond has a working slaved interface or not.

=head3 bond_primary_interface (optional)

This is the primary interface name in the bond.

=head3 bond_primary_reselect (optional)

This is the primary interface reselect policy.

=head3 bond_active_interface (optional)

This is the interface currently being used by the bond.

=head3 bond_mac_address (optional)

This is the current / active MAC address in use by the bond interface.

=head3 bond_mii_polling_interval (optional)

This is how often, in milliseconds, that the link (mii) status is manually checked.

=head3 bond_up_delay (optional)

This is how long the bond waits, in millisecinds, after an interfaces comes up before considering it for use.

=head3 bond_down_delay (optional)

This is how long the bond waits, in millisecinds, after an interfaces goes down before considering it failed.

head3 bond_bridge_uuid (optional)

This is the C<< briges >> -> C<< bridge_uuid >> of the bridge this bond is connected to, if any.

=cut
sub insert_or_update_bonds
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_bonds()" }});
	
	my $uuid                      = defined $parameter->{uuid}                      ? $parameter->{uuid}                      : "";
	my $file                      = defined $parameter->{file}                      ? $parameter->{file}                      : "";
	my $line                      = defined $parameter->{line}                      ? $parameter->{line}                      : "";
	my $delete                    = defined $parameter->{'delete'}                  ? $parameter->{'delete'}                  : "";
	my $bond_uuid                 = defined $parameter->{bond_uuid}                 ? $parameter->{bond_uuid}                 : "";
	my $bond_host_uuid            = defined $parameter->{bond_host_uuid}            ? $parameter->{bond_host_uuid}            : $anvil->data->{sys}{host_uuid};
	my $bond_name                 = defined $parameter->{bond_name}                 ? $parameter->{bond_name}                 : "";
	my $bond_mode                 = defined $parameter->{bond_mode}                 ? $parameter->{bond_mode}                 : "";
	my $bond_mtu                  = defined $parameter->{bond_mtu}                  ? $parameter->{bond_mtu}                  : "";
	my $bond_primary_interface    = defined $parameter->{bond_primary_interface}    ? $parameter->{bond_primary_interface}    : "";
	my $bond_primary_reselect     = defined $parameter->{bond_primary_reselect}     ? $parameter->{bond_primary_reselect}     : "";
	my $bond_active_interface     = defined $parameter->{bond_active_interface}     ? $parameter->{bond_active_interface}     : "";
	my $bond_mii_polling_interval = defined $parameter->{bond_mii_polling_interval} ? $parameter->{bond_mii_polling_interval} : "";
	my $bond_up_delay             = defined $parameter->{bond_up_delay}             ? $parameter->{bond_up_delay}             : "";
	my $bond_down_delay           = defined $parameter->{bond_down_delay}           ? $parameter->{bond_down_delay}           : "";
	my $bond_mac_address          = defined $parameter->{bond_mac_address}          ? $parameter->{bond_mac_address}          : "";
	my $bond_operational          = defined $parameter->{bond_operational}          ? $parameter->{bond_operational}          : "";
	my $bond_bridge_uuid          = defined $parameter->{bond_bridge_uuid}          ? $parameter->{bond_bridge_uuid}          : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                      => $uuid, 
		file                      => $file, 
		line                      => $line, 
		'delete'                  => $delete, 
		bond_uuid                 => $bond_uuid, 
		bond_host_uuid            => $bond_host_uuid, 
		bond_name                 => $bond_name, 
		bond_mode                 => $bond_mode, 
		bond_mtu                  => $bond_mtu, 
		bond_primary_interface    => $bond_primary_interface, 
		bond_primary_reselect     => $bond_primary_reselect, 
		bond_active_interface     => $bond_active_interface, 
		bond_mii_polling_interval => $bond_mii_polling_interval, 
		bond_up_delay             => $bond_up_delay, 
		bond_down_delay           => $bond_down_delay, 
		bond_mac_address          => $bond_mac_address, 
		bond_operational          => $bond_operational, 
		bond_bridge_uuid          => $bond_bridge_uuid, 
	}});
	
	if (not $delete)
	{
		if (not $bond_name)
		{
			# Throw an error and exit.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_bonds()", parameter => "bond_name" }});
			return("");
		}
		if (not $bond_mode)
		{
			# Throw an error and exit.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_bonds()", parameter => "bond_mode" }});
			return("");
		}
		if (not $bond_bridge_uuid)
		{
			# This has to be 'NULL' if not defined.
			$bond_bridge_uuid = 'NULL';
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { bond_bridge_uuid => $bond_bridge_uuid }});
		}
	}
	
	# If we don't have a UUID, see if we can find one for the given bond server name.
	if (not $bond_uuid)
	{
		my $query = "
SELECT 
    bond_uuid 
FROM 
    bonds 
WHERE 
    bond_name      = ".$anvil->Database->quote($bond_name)." 
AND 
    bond_host_uuid = ".$anvil->Database->quote($bond_host_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$bond_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { bond_uuid => $bond_uuid }});
		}
	}
	
	if ($delete)
	{
		if (not $bond_uuid)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_bonds()", parameter => "bond_uuid" }});
			return("");
		}
		else
		{
			# Delete it
			my $query = "SELECT bond_operational FROM bonds WHERE bond_uuid = ".$anvil->Database->quote($bond_uuid).";";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count, 
			}});
			if ($count)
			{
				my $old_bond_operational = $results->[0]->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { old_bond_operational => $old_bond_operational }});
				
				if ($old_bond_operational ne "DELETED")
				{
					my $query = "
UPDATE 
    bonds 
SET 
    bond_operational = 'DELETED', 
    modified_date    = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE 
    bond_uuid = ".$anvil->Database->quote($bond_uuid)."
;";
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
				return($bond_uuid);
			}
			else
			{
				# Not found.
				return("");
			}
		}
	}
	
	# If I still don't have an bond_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { bond_uuid => $bond_uuid }});
	if (not $bond_uuid)
	{
		# It's possible that this is called before the host is recorded in the database. So to be
		# safe, we'll return without doing anything if there is no host_uuid in the database.
		my $hosts = $anvil->Database->get_hosts();
		my $found = 0;
		foreach my $hash_ref (@{$hosts})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"hash_ref->{host_uuid}" => $hash_ref->{host_uuid}, 
				"sys::host_uuid"        => $anvil->data->{sys}{host_uuid}, 
			}});
			if ($hash_ref->{host_uuid} eq $anvil->data->{sys}{host_uuid})
			{
				$found = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { found => $found }});
			}
		}
		if (not $found)
		{
			# We're out.
			return("");
		}
		
		# INSERT
		$bond_uuid = $anvil->Get->uuid();
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { bond_uuid => $bond_uuid }});
		
		my $query = "
INSERT INTO 
    bonds 
(
    bond_uuid, 
    bond_host_uuid, 
    bond_name, 
    bond_mode, 
    bond_mtu, 
    bond_primary_interface, 
    bond_primary_reselect, 
    bond_active_interface, 
    bond_mii_polling_interval, 
    bond_up_delay, 
    bond_down_delay, 
    bond_mac_address, 
    bond_operational, 
    bond_bridge_uuid, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($bond_uuid).", 
    ".$anvil->Database->quote($bond_host_uuid).", 
    ".$anvil->Database->quote($bond_name).", 
    ".$anvil->Database->quote($bond_mode).", 
    ".$anvil->Database->quote($bond_mtu).", 
    ".$anvil->Database->quote($bond_primary_interface).", 
    ".$anvil->Database->quote($bond_primary_reselect).", 
    ".$anvil->Database->quote($bond_active_interface).", 
    ".$anvil->Database->quote($bond_mii_polling_interval).", 
    ".$anvil->Database->quote($bond_up_delay).", 
    ".$anvil->Database->quote($bond_down_delay).", 
    ".$anvil->Database->quote($bond_mac_address).", 
    ".$anvil->Database->quote($bond_operational).", 
    ".$anvil->Database->quote($bond_bridge_uuid).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$query =~ s/'NULL'/NULL/g;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    bond_host_uuid, 
    bond_name, 
    bond_mode, 
    bond_mtu, 
    bond_primary_interface, 
    bond_primary_reselect, 
    bond_active_interface, 
    bond_mii_polling_interval, 
    bond_up_delay, 
    bond_down_delay, 
    bond_mac_address, 
    bond_operational, 
    bond_bridge_uuid 
FROM 
    bonds 
WHERE 
    bond_uuid = ".$anvil->Database->quote($bond_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a bond_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "bond_uuid", uuid => $bond_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_bond_host_uuid            = $row->[0];
			my $old_bond_name                 = $row->[1];
			my $old_bond_mode                 = $row->[2];
			my $old_bond_mtu                  = $row->[3];
			my $old_bond_primary_interface    = $row->[4];
			my $old_bond_primary_reselect     = $row->[5];
			my $old_bond_active_interface     = $row->[6];
			my $old_bond_mii_polling_interval = $row->[7];
			my $old_bond_up_delay             = $row->[8];
			my $old_bond_down_delay           = $row->[9];
			my $old_bond_mac_address          = $row->[10];
			my $old_bond_operational          = $row->[11];
			my $old_bond_bridge_uuid          = $row->[12];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_bond_host_uuid            => $old_bond_host_uuid, 
				old_bond_name                 => $old_bond_name, 
				old_bond_mode                 => $old_bond_mode, 
				old_bond_mtu                  => $old_bond_mtu, 
				old_bond_primary_interface    => $old_bond_primary_interface, 
				old_bond_primary_reselect     => $old_bond_primary_reselect, 
				old_bond_active_interface     => $old_bond_active_interface, 
				old_bond_mii_polling_interval => $old_bond_mii_polling_interval, 
				old_bond_up_delay             => $old_bond_up_delay, 
				old_bond_down_delay           => $old_bond_down_delay, 
				old_bond_mac_address          => $old_bond_mac_address, 
				old_bond_operational          => $old_bond_operational, 
				old_bond_bridge_uuid          => $old_bond_bridge_uuid, 
			}});
			
			# Anything change?
			if (($old_bond_host_uuid            ne $bond_host_uuid)            or 
			    ($old_bond_name                 ne $bond_name)                 or 
			    ($old_bond_mode                 ne $bond_mode)                 or 
			    ($old_bond_mtu                  ne $bond_mtu)                  or 
			    ($old_bond_primary_interface    ne $bond_primary_interface)    or 
			    ($old_bond_primary_reselect     ne $bond_primary_reselect)     or 
			    ($old_bond_active_interface     ne $bond_active_interface)     or 
			    ($old_bond_mii_polling_interval ne $bond_mii_polling_interval) or 
			    ($old_bond_up_delay             ne $bond_up_delay)             or 
			    ($old_bond_down_delay           ne $bond_down_delay)           or 
			    ($old_bond_mac_address          ne $bond_mac_address)          or 
			    ($old_bond_bridge_uuid          ne $bond_bridge_uuid)          or 
			    ($old_bond_operational          ne $bond_operational))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    bonds 
SET 
    bond_host_uuid            = ".$anvil->Database->quote($bond_host_uuid).",  
    bond_name                 = ".$anvil->Database->quote($bond_name).", 
    bond_mode                 = ".$anvil->Database->quote($bond_mode).", 
    bond_mtu                  = ".$anvil->Database->quote($bond_mtu).", 
    bond_primary_interface    = ".$anvil->Database->quote($bond_primary_interface).", 
    bond_primary_reselect     = ".$anvil->Database->quote($bond_primary_reselect).", 
    bond_active_interface     = ".$anvil->Database->quote($bond_active_interface).", 
    bond_mii_polling_interval = ".$anvil->Database->quote($bond_mii_polling_interval).", 
    bond_up_delay             = ".$anvil->Database->quote($bond_up_delay).", 
    bond_down_delay           = ".$anvil->Database->quote($bond_down_delay).", 
    bond_mac_address          = ".$anvil->Database->quote($bond_mac_address).", 
    bond_operational          = ".$anvil->Database->quote($bond_operational).", 
    bond_bridge_uuid          = ".$anvil->Database->quote($bond_bridge_uuid).", 
    modified_date             = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    bond_uuid                 = ".$anvil->Database->quote($bond_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	return($bond_uuid);
}


=head2 insert_or_update_fences

This updates (or inserts) a record in the 'fences' table. The C<< fence_uuid >> UUID will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 fence_agent (required)

This is the name of the fence agent to use when communicating with this fence device. The agent must be installed on any machine that may need to fence (or check the fence/power state of) a node.

=head3 fence_arguments (optional, but generally required in practice)

This is the string that tells machines how to communicate / control the the fence device. This is used when configuring pacemaker's stonith (fencing). 

The exact formatting needs to match the STDIN parameters supported by C<< fence_agent >>. Please see C<< STDIN PARAMETERS >> section of the fence agent man page for this device.

For example, this can be set to:

* C<< ip="10.201.11.1" lanplus="1" username="admin" password="super secret password" 

B<< NOTES >>: 
* If C<< password_script >> is used, it is required that the user has copied the script to the nodes.
* Do not use C<< action="..." >> or the fence agent name. If either is found in the string, they will be ignored.
* Do not use C<< delay >>. It will be determined automatically based on which node has the most servers running on it.
* If this is set to C<< DELETED >>, the fence device is considered no longer used and it will be ignored by C<< Database->get_fences() >>.

=head3 fence_name (required)

This is the name of the fence device. Genreally, this is the short host name of the device.

=head3 fence_uuid (required)

The default value is the fence's UUID. When passed, the specific record is updated.

=cut
sub insert_or_update_fences
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_fences()" }});
	
	my $uuid            = defined $parameter->{uuid}            ? $parameter->{uuid}            : "";
	my $file            = defined $parameter->{file}            ? $parameter->{file}            : "";
	my $line            = defined $parameter->{line}            ? $parameter->{line}            : "";
	my $fence_agent     = defined $parameter->{fence_agent}     ? $parameter->{fence_agent}     : "";
	my $fence_arguments = defined $parameter->{fence_arguments} ? $parameter->{fence_arguments} : "";
	my $fence_name      = defined $parameter->{fence_name}      ? $parameter->{fence_name}      : "";
	my $fence_uuid      = defined $parameter->{fence_uuid}      ? $parameter->{fence_uuid}      : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid            => $uuid, 
		file            => $file, 
		line            => $line, 
		fence_agent     => $fence_agent, 
		fence_arguments => $fence_arguments =~ /passwork=/ ? $anvil->Log->is_secure($fence_arguments) : $fence_arguments, 
		fence_name      => $fence_name, 
		fence_uuid      => $fence_uuid, 
	}});
	
	# I can't imagine why you'd ever use no arguments, but it's not impossible. This doesn't include the
	# "port", which could be all that 's needed I suppose.
	if (not $fence_agent)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_fences()", parameter => "fence_agent" }});
		return("");
	}
	if (not $fence_name)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_fences()", parameter => "fence_name" }});
		return("");
	}
	
	# Do we have a UUID?
	if (not $fence_uuid)
	{
		my $query = "
SELECT 
    fence_uuid 
FROM 
    fences 
WHERE 
    fence_name = ".$anvil->Database->quote($fence_name)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$fence_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { fence_uuid => $fence_uuid }});
		}
	}
	
	# Do we have a UUID?
	if ($fence_uuid)
	{
		# Yup. Has something changed?
		my $query = "
SELECT 
    fence_agent, 
    fence_name, 
    fence_arguments  
FROM 
    fences 
WHERE 
    fence_uuid = ".$anvil->Database->quote($fence_uuid)."
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count,
		}});
		foreach my $row (@{$results})
		{
			my $old_fence_agent     = $row->[0];
			my $old_fence_name      = $row->[1];
			my $old_fence_arguments = $row->[2];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => {
				old_fence_agent     => $old_fence_agent,
				old_fence_name      => $old_fence_name =~ /passw/ ? $anvil->Log->is_secure($old_fence_name) : $old_fence_name, 
				old_fence_arguments => $old_fence_arguments, 
			}});
			if (($old_fence_agent     ne $fence_agent) or 
			    ($old_fence_name      ne $fence_name)  or 
			    ($old_fence_arguments ne $fence_arguments))
			{
				# Clear the stop data.
				my $query = "
UPDATE 
    fences
SET 
    fence_name      = ".$anvil->Database->quote($fence_name).", 
    fence_arguments = ".$anvil->Database->quote($fence_arguments).", 
    fence_agent     = ".$anvil->Database->quote($fence_agent).", 
    modified_date   = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE
    fence_uuid      = ".$anvil->Database->quote($fence_uuid)."
;";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query =~ /passw/ ? $anvil->Log->is_secure($query) : $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	else
	{
		# No, INSERT.
		   $fence_uuid = $anvil->Get->uuid();
		my $query      = "
INSERT INTO 
    fences 
(
    fence_uuid, 
    fence_name, 
    fence_arguments, 
    fence_agent, 
    modified_date
) VALUES (
    ".$anvil->Database->quote($fence_uuid).", 
    ".$anvil->Database->quote($fence_name).",
    ".$anvil->Database->quote($fence_arguments).",
    ".$anvil->Database->quote($fence_agent).",
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query =~ /passw/ ? $anvil->Log->is_secure($query) : $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	
	return($fence_uuid);
}


=head2 insert_or_update_file_locations

This updates (or inserts) a record in the 'file_locations' table. The C<< file_location_uuid >> referencing the database row will be returned.

This table is used to track which of the files in the database are on a given host.

If there is an error, an empty string is returned.

Parameters;

=head3 file_location_uuid (optional)

The record to update, when passed.

If not passed, a check will be made to see if an existing entry is found for C<< file_name >>. If found, that entry will be updated. If not found, a new record will be inserted.

=head3 file_location_file_uuid (required)

This is the C<< files >> -> C<< file_uuid >> referenced by this record.

=head3 file_location_host_uuid (optional, default 'sys::host_uuid')

This is the C<< hosts >> -> C<< host_uuid >> referenced by this record.

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=cut
sub insert_or_update_file_locations
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_file_locations()" }});
	
	my $uuid                    = defined $parameter->{uuid}                    ? $parameter->{uuid}                    : "";
	my $file                    = defined $parameter->{file}                    ? $parameter->{file}                    : "";
	my $line                    = defined $parameter->{line}                    ? $parameter->{line}                    : "";
	my $file_location_uuid      = defined $parameter->{file_location_uuid}      ? $parameter->{file_location_uuid}      : "";
	my $file_location_file_uuid = defined $parameter->{file_location_file_uuid} ? $parameter->{file_location_file_uuid} : "";
	my $file_location_host_uuid = defined $parameter->{file_location_host_uuid} ? $parameter->{file_location_host_uuid} : $anvil->data->{sys}{host_uuid};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                    => $uuid, 
		file_location_uuid      => $file_location_uuid, 
		file_location_file_uuid => $file_location_file_uuid, 
		file_location_host_uuid => $file_location_host_uuid, 
	}});
	
	if (not $file_location_file_uuid)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_file_locations()", parameter => "file_location_file_uuid" }});
		return("");
	}
	if (not $file_location_host_uuid)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_file_locations()", parameter => "file_location_host_uuid" }});
		return("");
	}
	
	# Made sure the file_uuuid and host_uuid are valid
	### TODO
	
	# If we don't have a UUID, see if we can find one for the given md5sum.
	if (not $file_location_uuid)
	{
		my $query = "
SELECT 
    file_location_uuid 
FROM 
    file_locations 
WHERE 
    file_location_file_uuid = ".$anvil->Database->quote($file_location_file_uuid)." 
AND
    file_location_host_uuid = ".$anvil->Database->quote($file_location_host_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$file_location_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { file_location_uuid => $file_location_uuid }});
		}
	}
	
	# If I still don't have an file_location_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { file_location_uuid => $file_location_uuid }});
	if (not $file_location_uuid)
	{
		# It's possible that this is called before the host is recorded in the database. So to be
		# safe, we'll return without doing anything if there is no host_uuid in the database.
		my $hosts = $anvil->Database->get_hosts();
		my $found = 0;
		foreach my $hash_ref (@{$hosts})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"hash_ref->{host_uuid}" => $hash_ref->{host_uuid}, 
				"sys::host_uuid"        => $anvil->data->{sys}{host_uuid}, 
			}});
			if ($hash_ref->{host_uuid} eq $anvil->data->{sys}{host_uuid})
			{
				$found = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { found => $found }});
			}
		}
		if (not $found)
		{
			# We're out.
			return("");
		}
		
		# INSERT
		$file_location_uuid = $anvil->Get->uuid();
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { file_location_uuid => $file_location_uuid }});
		
		my $query = "
INSERT INTO 
    file_locations 
(
    file_location_uuid, 
    file_location_file_uuid, 
    file_location_host_uuid, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($file_location_uuid).", 
    ".$anvil->Database->quote($file_location_file_uuid).", 
    ".$anvil->Database->quote($file_location_host_uuid).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    file_location_file_uuid, 
    file_location_host_uuid 
FROM 
    file_locations 
WHERE 
    file_location_uuid = ".$anvil->Database->quote($file_location_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a file_location_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "file_location_uuid", uuid => $file_location_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_file_location_file_uuid = $row->[0];
			my $old_file_location_host_uuid = $row->[1];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_file_location_file_uuid => $old_file_location_file_uuid, 
				old_file_location_host_uuid => $old_file_location_host_uuid, 
			}});
			
			# Anything change?
			if (($old_file_location_file_uuid ne $file_location_file_uuid) or 
			    ($old_file_location_host_uuid ne $file_location_host_uuid))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    file_locations 
SET 
    file_location_file_uuid = ".$anvil->Database->quote($file_location_file_uuid).", 
    file_location_host_uuid = ".$anvil->Database->quote($file_location_host_uuid).", 
    modified_date           = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    file_location_uuid      = ".$anvil->Database->quote($file_location_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	return($file_location_uuid);
}


=head2 insert_or_update_files

This updates (or inserts) a record in the 'files' table. The C<< file_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 file_uuid (optional)

If not passed, a check will be made to see if an existing entry is found for C<< file_name >>. If found, that entry will be updated. If not found, a new record will be inserted.

=head3 file_name (required)

This is the file's name.

=head3 file_directory (required)

This is the directory that the file is in. This is used to avoid conflict if two files of the same name exist in two places but are otherwise different.

=head3 file_size (required)

This is the file's size in bytes. It is recorded as a quick way to determine if the file has changed on disk.

=head3 file_md5sum (requred)

This is the sum as calculated when the file is first uploaded. Once recorded, it can't change.

=head3 file_type (required)

This is the file's type/purpose. The expected values are 'iso' (disc image a new server can be installed from or mounted in a virtual optical drive),  'rpm' (a package to install on a guest that provides access to Anvil! RPM software), 'script' (pre or post migration scripts), 'image' (images to use for newly created servers, instead of installing from an ISO or PXE), or 'other'. 

=head3 file_mtime (required)

This is the file's C<< mtime >> (modification time as a unix timestamp). This is used in case a file of the same name exists on two or more systems, but their size or md5sum differ. The file with the most recent mtime is used to update the older versions.

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=cut
sub insert_or_update_files
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_files()" }});
	
	my $uuid           = defined $parameter->{uuid}           ? $parameter->{uuid}           : "";
	my $file           = defined $parameter->{file}           ? $parameter->{file}           : "";
	my $line           = defined $parameter->{line}           ? $parameter->{line}           : "";
	my $file_uuid      = defined $parameter->{file_uuid}      ? $parameter->{file_uuid}      : "";
	my $file_name      = defined $parameter->{file_name}      ? $parameter->{file_name}      : "";
	my $file_directory = defined $parameter->{file_directory} ? $parameter->{file_directory} : "";
	my $file_size      = defined $parameter->{file_size}      ? $parameter->{file_size}      : "";
	my $file_md5sum    = defined $parameter->{file_md5sum}    ? $parameter->{file_md5sum}    : "";
	my $file_type      = defined $parameter->{file_type}      ? $parameter->{file_type}      : "";
	my $file_mtime     = defined $parameter->{file_mtime}     ? $parameter->{file_mtime}     : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid           => $uuid, 
		file           => $file,
		line           => $line,
		file_uuid      => $file_uuid, 
		file_name      => $file_name, 
		file_directory => $file_directory, 
		file_size      => $file_size, 
		file_md5sum    => $file_md5sum, 
		file_type      => $file_type, 
		file_mtime     => $file_mtime, 
	}});
	
	if (not $file_name)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_files()", parameter => "file_name" }});
		return("");
	}
	if (not $file_name)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_files()", parameter => "file_name" }});
		return("");
	}
	if (not $file_directory)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_files()", parameter => "file_directory" }});
		return("");
	}
	if (not $file_md5sum)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_files()", parameter => "file_md5sum" }});
		return("");
	}
	if (not $file_type)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_files()", parameter => "file_type" }});
		return("");
	}
	if (not $file_mtime)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_files()", parameter => "file_mtime" }});
		return("");
	}
	
	# If we don't have a UUID, see if we can find one for the given md5sum.
	if (not $file_uuid)
	{
		my $query = "
SELECT 
    file_uuid 
FROM 
    files 
WHERE 
    file_md5sum = ".$anvil->Database->quote($file_md5sum)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$file_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { file_uuid => $file_uuid }});
		}
	}
	
	# If I still don't have an file_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { file_uuid => $file_uuid }});
	if (not $file_uuid)
	{
		# It's possible that this is called before the host is recorded in the database. So to be
		# safe, we'll return without doing anything if there is no host_uuid in the database.
		my $hosts = $anvil->Database->get_hosts();
		my $found = 0;
		foreach my $hash_ref (@{$hosts})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"hash_ref->{host_uuid}" => $hash_ref->{host_uuid}, 
				"sys::host_uuid"        => $anvil->data->{sys}{host_uuid}, 
			}});
			if ($hash_ref->{host_uuid} eq $anvil->data->{sys}{host_uuid})
			{
				$found = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { found => $found }});
			}
		}
		if (not $found)
		{
			# We're out.
			return("");
		}
		
		# INSERT
		$file_uuid = $anvil->Get->uuid();
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { file_uuid => $file_uuid }});
		
		my $query = "
INSERT INTO 
    files 
(
    file_uuid, 
    file_name, 
    file_directory, 
    file_size, 
    file_md5sum, 
    file_type, 
    file_mtime, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($file_uuid).", 
    ".$anvil->Database->quote($file_name).", 
    ".$anvil->Database->quote($file_directory).", 
    ".$anvil->Database->quote($file_size).", 
    ".$anvil->Database->quote($file_md5sum).", 
    ".$anvil->Database->quote($file_type).", 
    ".$anvil->Database->quote($file_mtime).", 
   ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    file_name, 
    file_directory, 
    file_size, 
    file_md5sum, 
    file_type, 
    file_mtime 
FROM 
    files 
WHERE 
    file_uuid = ".$anvil->Database->quote($file_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a file_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "file_uuid", uuid => $file_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_file_name      = $row->[0];
			my $old_file_directory = $row->[1];
			my $old_file_size      = $row->[1];
			my $old_file_md5sum    = $row->[2]; 
			my $old_file_type      = $row->[3]; 
			my $old_file_mtime     = $row->[4]; 
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_file_name      => $old_file_name, 
				old_file_directory => $old_file_directory, 
				old_file_size      => $old_file_size, 
				old_file_md5sum    => $old_file_md5sum, 
				old_file_type      => $old_file_type, 
				old_file_mtime     => $old_file_mtime, 
			}});
			
			# Anything change?
			if (($old_file_name      ne $file_name)      or 
			    ($old_file_directory ne $file_directory) or 
			    ($old_file_size      ne $file_size)      or 
			    ($old_file_md5sum    ne $file_md5sum)    or 
			    ($old_file_mtime     ne $file_mtime)     or 
			    ($old_file_type      ne $file_type))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    files 
SET 
    file_name      = ".$anvil->Database->quote($file_name).", 
    file_directory = ".$anvil->Database->quote($file_directory).", 
    file_size      = ".$anvil->Database->quote($file_size).", 
    file_md5sum    = ".$anvil->Database->quote($file_md5sum).", 
    file_type      = ".$anvil->Database->quote($file_type).", 
    file_mtime     = ".$anvil->Database->quote($file_mtime).", 
    modified_date  = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    file_uuid      = ".$anvil->Database->quote($file_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	return($file_uuid);
}


=head2 insert_or_update_host_keys

This updates (or inserts) a record in the 'host_keys' table. The C<< host_key_uuid >> UUID will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 host_key_host_uuid (optional, default is Get->host_uuid)

This is the host that the corresponding user and key belong to.

=head3 host_key_public_key (required)

This is the B<<PUBLIC>> key for the user, the full line stored in the user's C<< ~/.ssh/id_rsa.pub >> file.

=head3 host_key_user_name (required)

This is the name of the user that the public key belongs to.

=head3 host_key_uuid (optional)

This is the specific record to update. If not provides, a search will be made to find a matching entry. If found, the record will be updated if one of the values has changed. If not, a new record will be inserted.

=cut
sub insert_or_update_host_keys
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_host_keys()" }});
	
	my $uuid                = defined $parameter->{uuid}                ? $parameter->{uuid}                : "";
	my $file                = defined $parameter->{file}                ? $parameter->{file}                : "";
	my $line                = defined $parameter->{line}                ? $parameter->{line}                : "";
	my $host_key_host_uuid  = defined $parameter->{host_key_host_uuid}  ? $parameter->{host_key_host_uuid}  : $anvil->Get->host_uuid;
	my $host_key_public_key = defined $parameter->{host_key_public_key} ? $parameter->{host_key_public_key} : "";
	my $host_key_user_name  = defined $parameter->{host_key_user_name}  ? $parameter->{host_key_user_name}  : "";
	my $host_key_uuid       = defined $parameter->{host_key_uuid}       ? $parameter->{host_key_uuid}       : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                => $uuid, 
		file                => $file, 
		line                => $line, 
		host_key_host_uuid  => $host_key_host_uuid, 
		host_key_public_key => $host_key_public_key, 
		host_key_user_name  => $host_key_user_name, 
		host_key_uuid       => $host_key_uuid, 
	}});
	
	if (not $host_key_public_key)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_host_keys()", parameter => "host_key_public_key" }});
		return("");
	}
	if (not $host_key_user_name)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_host_keys()", parameter => "host_key_user_name" }});
		return("");
	}
	
	# If we don't have a UUID, see if we can find one for the given user and host.
	if (not $host_key_uuid)
	{
		my $query = "
SELECT 
    host_key_uuid 
FROM 
    host_keys 
WHERE 
    host_key_user_name = ".$anvil->Database->quote($host_key_user_name)." 
AND 
    host_key_host_uuid = ".$anvil->Database->quote($host_key_host_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$host_key_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_key_uuid => $host_key_uuid }});
		}
	}
	
	# If I still don't have an host_key_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_key_uuid => $host_key_uuid }});
	if (not $host_key_uuid)
	{
		# INSERT
		$host_key_uuid = $anvil->Get->uuid();
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_key_uuid => $host_key_uuid }});
		
		my $query = "
INSERT INTO 
    host_keys 
(
    host_key_uuid, 
    host_key_host_uuid, 
    host_key_public_key, 
    host_key_user_name, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($host_key_uuid).", 
    ".$anvil->Database->quote($host_key_host_uuid).", 
    ".$anvil->Database->quote($host_key_public_key).", 
    ".$anvil->Database->quote($host_key_user_name).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    host_key_host_uuid, 
    host_key_public_key, 
    host_key_user_name 
FROM 
    host_keys 
WHERE 
    host_key_uuid = ".$anvil->Database->quote($host_key_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a host_key_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "host_key_uuid", uuid => $host_key_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_host_key_host_uuid  = $row->[0];
			my $old_host_key_public_key = $row->[1];
			my $old_host_key_user_name  = $row->[2];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_host_key_host_uuid  => $old_host_key_host_uuid, 
				old_host_key_public_key => $old_host_key_public_key, 
				old_host_key_user_name  => $old_host_key_user_name, 
			}});
			
			# Anything change?
			if (($old_host_key_host_uuid  ne $host_key_host_uuid)  or 
			    ($old_host_key_public_key ne $host_key_public_key) or 
			    ($old_host_key_user_name  ne $host_key_user_name))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    host_keys 
SET 
    host_key_host_uuid  = ".$anvil->Database->quote($host_key_host_uuid).",  
    host_key_public_key = ".$anvil->Database->quote($host_key_public_key).", 
    host_key_user_name  = ".$anvil->Database->quote($host_key_user_name).", 
    modified_date       = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    host_key_uuid       = ".$anvil->Database->quote($host_key_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_key_uuid => $host_key_uuid }});
	return($host_key_uuid);
}


=head2 insert_or_update_hosts

This updates (or inserts) a record in the 'hosts' table. The C<< host_uuid >> UUID will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 host_ipmi (optional)

This is an optional string that tells machines how to check/control the power of this host. This allows C<< fence_agentlan >> to query and manipulate the power of the host from another host. 

There are three times this information is used;

* When one node needs to fence the other. Specifically, the information is parsed and used to configure stonith (fencing) in pacemaker.
* When a Striker dashboard determines that, after a power or thermal event, it is safe to restart the node
* When it is time to connect a DR host to update/synchronize storage.

The exact formatting needs to match the STDIN parameters supported by C<< fence_agentlan >>. Please see C<< man fence_agentlan >> -> C<< STDIN PARAMETERS >> for more information.

For example, this can be set to:

* C<< ip="10.201.11.1" lanplus="1" username="admin" password="super secret password" 

B<< NOTES >>: 
* If C<< password_script >> is used, it is required that the user has copied the script to all machines on that could use this information to fence/boot a target.
* Do not use C<< fence_agentlan >> or C<< action="..." >>. If either is found in the string, it will be ignored.
* Do not use C<< delay >>. It will be determined automatically based on which node has the most servers running on it.

=head3 host_key (required)

The is the host's public key used by other machines to validate this machine when connecting to it using ssh. The value comes from C<< /etc/ssh/ssh_host_ecdsa_key.pub >>. An example string would be C<< ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBMLEG+mcczSUgmcSuRNZc5OAFPa7IudZQv/cYWzCzmlKPMkIdcNiYDuFM1iFNiV9wVtAvkIXVSkOe2Ah/BGt6fQ= >>.

=head3 host_name (required)

This default value is the local host name.

=head3 host_type (required)

This default value is the value returned by C<< System->get_host_type >>.

=head3 host_uuid (required)

The default value is the host's UUID (as returned by C<< Get->host_uuid >>.

=cut
sub insert_or_update_hosts
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_hosts()" }});
	
	my $uuid      = defined $parameter->{uuid}      ? $parameter->{uuid}      : "";
	my $file      = defined $parameter->{file}      ? $parameter->{file}      : "";
	my $line      = defined $parameter->{line}      ? $parameter->{line}      : "";
	my $host_ipmi = defined $parameter->{host_ipmi} ? $parameter->{host_ipmi} : "";
	my $host_key  = defined $parameter->{host_key}  ? $parameter->{host_key}  : "";
	my $host_name = defined $parameter->{host_name} ? $parameter->{host_name} : $anvil->_host_name;
	my $host_type = defined $parameter->{host_type} ? $parameter->{host_type} : $anvil->System->get_host_type;
	my $host_uuid = defined $parameter->{host_uuid} ? $parameter->{host_uuid} : $anvil->Get->host_uuid;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid      => $uuid, 
		file      => $file, 
		line      => $line, 
		host_ipmi => $host_ipmi =~ /passw/ ? $anvil->Log->is_secure($host_ipmi) : $host_ipmi, 
		host_key  => $host_key, 
		host_name => $host_name, 
		host_type => $host_type, 
		host_uuid => $host_uuid, 
	}});
	
	if (not $host_name)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_hosts()", parameter => "host_name" }});
		return("");
	}
	if (not $host_uuid)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_hosts()", parameter => "host_uuid" }});
		return("");
	}
	
	# If we're looking at ourselves and we don't have the host_key, read it in.
	if ((not $host_key) && ($host_uuid eq $anvil->Get->host_uuid))
	{
		$host_key =  $anvil->Storage->read_file({file => $anvil->data->{path}{data}{host_ssh_key}});
		$host_key =~ s/\n$//;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_key => $host_key }});
	}
	
	# Read the old values, if they exist.
	my $old_host_ipmi = "";
	my $old_host_name = "";
	my $old_host_type = "";
	my $old_host_key  = "";
	my $query         = "
SELECT 
    host_ipmi, 
    host_name, 
    host_type, 
    host_key  
FROM 
    hosts 
WHERE 
    host_uuid = ".$anvil->Database->quote($host_uuid)."
;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	my $results = $anvil->Database->query({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count,
	}});
	foreach my $row (@{$results})
	{
		$old_host_ipmi = $row->[0];
		$old_host_name = $row->[1];
		$old_host_type = $row->[2];
		$old_host_key  = $row->[3];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => {
			old_host_ipmi => $old_host_ipmi,
			old_host_name => $old_host_name =~ /passw/ ? $anvil->Log->is_secure($old_host_name) : $old_host_name, 
			old_host_type => $old_host_type, 
			old_host_key  => $old_host_key, 
		}});
	}
	if (not $count)
	{
		# Add this host to the database
		my $query = "
INSERT INTO 
    hosts 
(
    host_uuid, 
    host_name, 
    host_type, 
    host_key, 
    host_ipmi, 
    modified_date
) VALUES (
    ".$anvil->Database->quote($host_uuid).", 
    ".$anvil->Database->quote($host_name).",
    ".$anvil->Database->quote($host_type).",
    ".$anvil->Database->quote($host_key).",
    ".$anvil->Database->quote($host_ipmi).",
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query =~ /passw/ ? $anvil->Log->is_secure($query) : $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	elsif (($old_host_name ne $host_name) or 
	       ($old_host_type ne $host_type) or 
	       ($old_host_key  ne $host_key))
	{
		# Clear the stop data.
		my $query = "
UPDATE 
    hosts
SET 
    host_name     = ".$anvil->Database->quote($host_name).", 
    host_type     = ".$anvil->Database->quote($host_type).", 
    host_key      = ".$anvil->Database->quote($host_key).", 
    host_ipmi     = ".$anvil->Database->quote($host_ipmi).", 
    modified_date = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE
    host_uuid     = ".$anvil->Database->quote($host_uuid)."
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query =~ /passw/ ? $anvil->Log->is_secure($query) : $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0126", variables => { method => "Database->insert_or_update_hosts()" }});
	return($host_uuid);
}


=head2 insert_or_update_ip_addresses

This updates (or inserts) a record in the 'ip_addresses' table. The C<< ip_address_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 delete (optional, default '0')

When set to C<< 1 >>, the C<< ip_address_note >> is set to C<< DELETED >>, and nothing else is changed. If set, only C<< ip_address_uuid >> or C<< ip_address_address >> are required.

=head3 ip_address_address (required)

This is the acual IP address. It's tested with IPv4 addresses in dotted-decimal format, though it can also store IPv6 addresses. If this is set to C<< 0 >>, it will be treated as deleted and will be ignored (unless a new IP is assigned to the same interface in the future).

=head3 ip_address_uuid (optional)

If not passed, a check will be made to see if an existing entry is found for C<< ip_address_address >>. If found, that entry will be updated. If not found, a new record will be inserted.

=head3 ip_address_host_uuid (optional)

This is the host that the IP address is on. If not passed, the local C<< sys::host_uuid >> will be used (indicating it is a local IP address).

=head3 ip_address_on_type (required)

This indicates what type of interface the IP address is on. This must be either C<< interface >>, C<< bond >> or C<< bridge >>. 

=head3 ip_address_on_uuid (required)

This is the UUID of the bridge, bond or interface that this IP address is on.

=head3 ip_address_subnet_mask (required)

This is the subnet mask for the IP address. It is tested with IPv4 in dotted decimal format, though it can also store IPv6 format subnet masks.

=head3 ip_address_default_gateway (optional, default '0')

If a gateway address is set, and this is set to C<< 1 >>, the associated interface will be the default gateway for the host.

=head3 ip_address_gateway (optional)

This is an option gateway IP address for this interface.

=head3 ip_address_dns (optional)

This is a comma-separated list of DNS servers used to resolve host names. This is recorded, but ignored unless C<< ip_address_gateway >> is set. Example format is C<< 8.8.8.8 >> or C<< 8.8.8.8,4.4.4.4 >>.

=head3 ip_address_note (optional)

This can be set to C<< DELETED >> when the IP address is no longer in use.

=cut
sub insert_or_update_ip_addresses
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_ip_addresses()" }});
	
	my $delete                     = defined $parameter->{'delete'}                   ? $parameter->{'delete'}                   : 0;
	my $uuid                       = defined $parameter->{uuid}                       ? $parameter->{uuid}                       : "";
	my $file                       = defined $parameter->{file}                       ? $parameter->{file}                       : "";
	my $line                       = defined $parameter->{line}                       ? $parameter->{line}                       : "";
	my $ip_address_uuid            = defined $parameter->{ip_address_uuid}            ? $parameter->{ip_address_uuid}            : "";
	my $ip_address_host_uuid       = defined $parameter->{ip_address_host_uuid}       ? $parameter->{ip_address_host_uuid}       : $anvil->data->{sys}{host_uuid};
	my $ip_address_on_type         = defined $parameter->{ip_address_on_type}         ? $parameter->{ip_address_on_type}         : "";
	my $ip_address_on_uuid         = defined $parameter->{ip_address_on_uuid}         ? $parameter->{ip_address_on_uuid}         : "";
	my $ip_address_address         = defined $parameter->{ip_address_address}         ? $parameter->{ip_address_address}         : "";
	my $ip_address_subnet_mask     = defined $parameter->{ip_address_subnet_mask}     ? $parameter->{ip_address_subnet_mask}     : "";
	my $ip_address_gateway         = defined $parameter->{ip_address_gateway}         ? $parameter->{ip_address_gateway}         : "";
	my $ip_address_default_gateway = defined $parameter->{ip_address_default_gateway} ? $parameter->{ip_address_default_gateway} : 0;
	my $ip_address_dns             = defined $parameter->{ip_address_dns}             ? $parameter->{ip_address_dns}             : "";
	my $ip_address_note            = defined $parameter->{ip_address_note}            ? $parameter->{ip_address_note}            : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                       => $uuid, 
		file                       => $file, 
		line                       => $line, 
		'delete'                   => $delete, 
		ip_address_uuid            => $ip_address_uuid, 
		ip_address_host_uuid       => $ip_address_host_uuid, 
		ip_address_on_type         => $ip_address_on_type, 
		ip_address_on_uuid         => $ip_address_on_uuid, 
		ip_address_address         => $ip_address_address, 
		ip_address_subnet_mask     => $ip_address_subnet_mask, 
		ip_address_gateway         => $ip_address_gateway, 
		ip_address_default_gateway => $ip_address_default_gateway, 
		ip_address_dns             => $ip_address_dns, 
		ip_address_note            => $ip_address_note, 
	}});
	
	if (not $delete)
	{
		# Not deleting, verify we have what we need.
		if (not $ip_address_on_type)
		{
			# Throw an error and exit.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_ip_addresses()", parameter => "ip_address_on_type" }});
			return("");
		}
		if (not $ip_address_on_uuid)
		{
			# Throw an error and exit.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_ip_addresses()", parameter => "ip_address_on_uuid" }});
			return("");
		}
		if (not $ip_address_address)
		{
			# Throw an error and exit.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_ip_addresses()", parameter => "ip_address_address" }});
			return("");
		}
		if (not $ip_address_subnet_mask)
		{
			# Throw an error and exit.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_ip_addresses()", parameter => "ip_address_subnet_mask" }});
			return("");
		}
	}
	
	# If we don't have a UUID, see if we can find one for the given ip_address name.
	if (not $ip_address_uuid)
	{
		### NOTE: An IP can be on multiple machines at the same time (ie: 192.168.122.1), so we need
		###       to restrict to this host.
		my $query = "
SELECT 
    ip_address_uuid 
FROM 
    ip_addresses 
WHERE 
    ip_address_address   = ".$anvil->Database->quote($ip_address_address)." 
AND 
    ip_address_host_uuid = ".$anvil->Database->quote($ip_address_host_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$ip_address_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { ip_address_uuid => $ip_address_uuid }});
		}
	}
	
	if ($delete)
	{
		# We need the ip_address_uuid _or_ the ip_address_address
		if (not $ip_address_uuid)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_ip_addresses()", parameter => "ip_address_uuid" }});
			return("");
		}
		else
		{
			my $query = "SELECT ip_address_note FROM ip_addresses WHERE ip_address_uuid = ".$anvil->Database->quote($ip_address_uuid).";";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count, 
			}});
			if ($count)
			{
				my $old_ip_address_note = $results->[0]->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { old_ip_address_note => $old_ip_address_note }});
				
				if ($old_ip_address_note ne "DELETED")
				{
					my $query = "
UPDATE 
    ip_addresses 
SET 
    ip_address_note = 'DELETED',
    modified_date   = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE 
    ip_address_uuid = ".$anvil->Database->quote($ip_address_uuid)."
;";
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
				return($ip_address_uuid);
			}
			else
			{
				# Not found.
				return("");
			}
		}
	}
	
	# If I still don't have an ip_address_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { ip_address_uuid => $ip_address_uuid }});
	if (not $ip_address_uuid)
	{
		# It's possible that this is called before the host is recorded in the database. So to be
		# safe, we'll return without doing anything if there is no host_uuid in the database.
		my $hosts = $anvil->Database->get_hosts();
		my $found = 0;
		foreach my $hash_ref (@{$hosts})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"hash_ref->{host_uuid}" => $hash_ref->{host_uuid}, 
				"sys::host_uuid"        => $anvil->data->{sys}{host_uuid}, 
			}});
			if ($hash_ref->{host_uuid} eq $anvil->data->{sys}{host_uuid})
			{
				$found = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { found => $found }});
			}
		}
		if (not $found)
		{
			# We're out.
			return("");
		}
		
		# INSERT
		$ip_address_uuid = $anvil->Get->uuid();
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { ip_address_uuid => $ip_address_uuid }});
		
		my $query = "
INSERT INTO 
    ip_addresses 
(
    ip_address_uuid, 
    ip_address_host_uuid, 
    ip_address_on_type, 
    ip_address_on_uuid, 
    ip_address_address, 
    ip_address_subnet_mask, 
    ip_address_gateway, 
    ip_address_default_gateway, 
    ip_address_dns, 
    ip_address_note, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($ip_address_uuid).", 
    ".$anvil->Database->quote($ip_address_host_uuid).", 
    ".$anvil->Database->quote($ip_address_on_type).", 
    ".$anvil->Database->quote($ip_address_on_uuid).", 
    ".$anvil->Database->quote($ip_address_address).", 
    ".$anvil->Database->quote($ip_address_subnet_mask).", 
    ".$anvil->Database->quote($ip_address_gateway).", 
    ".$anvil->Database->quote($ip_address_default_gateway).", 
    ".$anvil->Database->quote($ip_address_dns).", 
    ".$anvil->Database->quote($ip_address_note).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    ip_address_host_uuid, 
    ip_address_on_type, 
    ip_address_on_uuid, 
    ip_address_address, 
    ip_address_subnet_mask, 
    ip_address_gateway, 
    ip_address_default_gateway, 
    ip_address_dns, 
    ip_address_note 
FROM 
    ip_addresses 
WHERE 
    ip_address_uuid = ".$anvil->Database->quote($ip_address_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have an ip_address_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "ip_address_uuid", uuid => $ip_address_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_ip_address_host_uuid       = $row->[0];
			my $old_ip_address_on_type         = $row->[1];
			my $old_ip_address_on_uuid         = $row->[2];
			my $old_ip_address_address         = $row->[3];
			my $old_ip_address_subnet_mask     = $row->[4];
			my $old_ip_address_gateway         = $row->[5];
			my $old_ip_address_default_gateway = $row->[6];
			my $old_ip_address_dns             = $row->[7];
			my $old_ip_address_note            = $row->[8];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_ip_address_host_uuid       => $old_ip_address_host_uuid, 
				old_ip_address_on_type         => $old_ip_address_on_type, 
				old_ip_address_on_uuid         => $old_ip_address_on_uuid, 
				old_ip_address_address         => $old_ip_address_address, 
				old_ip_address_subnet_mask     => $old_ip_address_subnet_mask, 
				old_ip_address_gateway         => $old_ip_address_gateway, 
				old_ip_address_default_gateway => $old_ip_address_default_gateway, 
				old_ip_address_dns             => $old_ip_address_dns, 
				old_ip_address_note            => $old_ip_address_note, 
			}});
			
			# Anything change?
			if (($old_ip_address_host_uuid       ne $ip_address_host_uuid)       or 
			    ($old_ip_address_on_type         ne $ip_address_on_type)         or 
			    ($old_ip_address_on_uuid         ne $ip_address_on_uuid)         or 
			    ($old_ip_address_address         ne $ip_address_address)         or 
			    ($old_ip_address_subnet_mask     ne $ip_address_subnet_mask)     or 
			    ($old_ip_address_gateway         ne $ip_address_gateway)         or 
			    ($old_ip_address_default_gateway ne $ip_address_default_gateway) or 
			    ($old_ip_address_dns             ne $ip_address_dns)             or 
			    ($old_ip_address_note            ne $ip_address_note))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    ip_addresses 
SET 
    ip_address_host_uuid       = ".$anvil->Database->quote($ip_address_host_uuid).",  
    ip_address_on_type         = ".$anvil->Database->quote($ip_address_on_type).",  
    ip_address_on_uuid         = ".$anvil->Database->quote($ip_address_on_uuid).", 
    ip_address_address         = ".$anvil->Database->quote($ip_address_address).", 
    ip_address_subnet_mask     = ".$anvil->Database->quote($ip_address_subnet_mask).", 
    ip_address_gateway         = ".$anvil->Database->quote($ip_address_gateway).", 
    ip_address_default_gateway = ".$anvil->Database->quote($ip_address_default_gateway).", 
    ip_address_dns             = ".$anvil->Database->quote($ip_address_dns).", 
    ip_address_note            = ".$anvil->Database->quote($ip_address_note).", 
    modified_date              = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    ip_address_uuid            = ".$anvil->Database->quote($ip_address_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	return($ip_address_uuid);
}


=head2 insert_or_update_jobs

This updates (or inserts) a record in the 'jobs' table. The C<< job_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 job_command (required)

This is the command (usually a shell call) to run.

=head3 job_data (optional)

This is used to pass information or store special progress data on a job. 

=head3 job_description (required*)

This is a string key to display in the body of the box showing that the job is running.

Variables can not be passed to this title key.

* This is not required when C<< update_progress_only >> is set

=head3 job_host_uuid (optional)

This is the host's UUID that this job entry belongs to. If not passed, C<< sys::host_uuid >> will be used.

=head3 job_name (required*)

This is the C<< job_name >> to INSERT or UPDATE. If a C<< job_uuid >> is passed, then the C<< job_name >> can be changed.

* This or C<< job_uuid >> must be passed

=head3 job_picked_up_at (optional)

When C<< anvil-daemon >> picks uup a job, it will record the (unix) time that it started.

=head3 job_picked_up_by (optional)

When C<< anvil-daemon >> picks up a job, it will record it's PID here.

=head3 job_progress (required)

This is a numeric value between C<< 0 >> and C<< 100 >>. The job will update this as it runs, with C<< 100 >> indicating that the job is complete. A value of C<< 0 >> will indicate that the job needs to be started. When the daemon picks up the job, it will set this to C<< 1 >>. Any value in between is set by the job itself.

=head3 job_status (optional)

This is used to tell the user the current status of the job. It can be included when C<< update_progress_only >> is set. 

The expected format is C<< <key>,!!var1!foo!!,...,!!varN!bar!!\n >>, one key/variable set per line. The new lines will be converted to C<< <br />\n >> automatically in Striker.

=head3 job_title (required*)

This is a string key to display in the title of the box showing that the job is running.

Variables can not be passed to this title key.

* This is not required when C<< update_progress_only >> is set

=head3 job_uuid (optional)

This is the C<< job_uuid >> to update. If it is not specified but the C<< job_name >> is, a check will be made to see if an entry already exists. If so, that row will be UPDATEd. If not, a random UUID will be generated and a new entry will be INSERTed.

* This or C<< job_name >> must be passed

=head3 update_progress_only (optional)

When set, the C<< job_progress >> will be updated. Optionally, if C<< job_status >>, C<< job_picked_up_by >>, C<< job_picked_up_at >> or C<< job_data >> are set, they may also be updated.

=cut 
sub insert_or_update_jobs
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_jobs()" }});
	
	my $uuid                 = defined $parameter->{uuid}                 ? $parameter->{uuid}                 : "";
	my $file                 = defined $parameter->{file}                 ? $parameter->{file}                 : "";
	my $line                 = defined $parameter->{line}                 ? $parameter->{line}                 : "";
	my $job_uuid             = defined $parameter->{job_uuid}             ? $parameter->{job_uuid}             : "";
	my $job_host_uuid        = defined $parameter->{job_host_uuid}        ? $parameter->{job_host_uuid}        : $anvil->data->{sys}{host_uuid};
	my $job_command          = defined $parameter->{job_command}          ? $parameter->{job_command}          : "";
	my $job_data             = defined $parameter->{job_data}             ? $parameter->{job_data}             : "";
	my $job_picked_up_by     = defined $parameter->{job_picked_up_by}     ? $parameter->{job_picked_up_by}     : 0;
	my $job_picked_up_at     = defined $parameter->{job_picked_up_at}     ? $parameter->{job_picked_up_at}     : 0;
	my $job_updated          = defined $parameter->{job_updated}          ? $parameter->{job_updated}          : time;
	my $job_name             = defined $parameter->{job_name}             ? $parameter->{job_name}             : "";
	my $job_progress         = defined $parameter->{job_progress}         ? $parameter->{job_progress}         : "";
	my $job_title            = defined $parameter->{job_title}            ? $parameter->{job_title}            : "";
	my $job_description      = defined $parameter->{job_description}      ? $parameter->{job_description}      : "";
	my $job_status           = defined $parameter->{job_status}           ? $parameter->{job_status}           : "";
	my $update_progress_only = defined $parameter->{update_progress_only} ? $parameter->{update_progress_only} : 0;
	my $clear_status         = defined $parameter->{clear_status}         ? $parameter->{clear_status}         : 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                 => $uuid, 
		file                 => $file, 
		line                 => $line, 
		job_uuid             => $job_uuid, 
		job_host_uuid        => $job_host_uuid, 
		job_command          => $job_command, 
		job_data             => $job_data, 
		job_picked_up_by     => $job_picked_up_by, 
		job_picked_up_at     => $job_picked_up_at, 
		job_updated          => $job_updated, 
		job_name             => $job_name, 
		job_progress         => $job_progress, 
		job_title            => $job_title, 
		job_description      => $job_description, 
		job_status           => $job_status, 
		update_progress_only => $update_progress_only, 
		clear_status         => $clear_status, 
	}});
	
	# If I have a job_uuid and update_progress_only is true, I only need the progress.
	my $problem = 0;
	
	# Do I have a valid progress?
	if (($job_progress !~ /^\d/) or ($job_progress < 0) or ($job_progress > 100))
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0138", variables => { method => "Database->insert_or_update_jobs()", job_progress => $job_progress }});
		$problem = 1;
	}
	
	# Make sure I have the either a valid job UUID or a name
	if ((not $anvil->Validate->is_uuid({uuid => $job_uuid})) && (not $job_name))
	{
		$anvil->Log->entry({source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__, level => 0, priority => "err", key => "log_0136", variables => { 
			method   => "Database->insert_or_update_jobs()", 
			job_name => $job_name,
			job_uuid => $job_uuid,
		}});
		$problem = 1;
	}
	
	# Unless I am updating the progress, make sure everything is passed.
	if (not $update_progress_only)
	{
		# Everything is required, except 'job_uuid'. So, job command?
		if (not $job_command)
		{
			$anvil->Log->entry({source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_jobs()", parameter => "job_command" }});
			$problem = 1;
		}
		
		# Job name?
		if (not $job_name)
		{
			$anvil->Log->entry({source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_jobs()", parameter => "job_name" }});
			$problem = 1;
		}
		
		# Job title?
		if (not $job_title)
		{
			$anvil->Log->entry({source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_jobs()", parameter => "job_title" }});
			$problem = 1;
		}
		
		# Job description?
		if (not $job_description)
		{
			$anvil->Log->entry({source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_jobs()", parameter => "job_description" }});
			$problem = 1;
		}
	}
	
	# We're done if there was a problem
	if ($problem)
	{
		return("");
	}
	
	# If we don't have a UUID, see if we can find one for the given job name.
	if (not $job_uuid)
	{
		my $query = "
SELECT 
    job_uuid 
FROM 
    jobs 
WHERE 
    job_name      = ".$anvil->Database->quote($job_name)." 
AND 
    job_command   = ".$anvil->Database->quote($job_command)." 
AND 
    job_data      = ".$anvil->Database->quote($job_data)." 
AND 
    job_host_uuid = ".$anvil->Database->quote($job_host_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		foreach my $row (@{$results})
		{
			$job_uuid = $row->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { job_uuid => $job_uuid }});
		}
	}
	
	# Now make sure I have a job_uuid if I am updating.
	if (($update_progress_only) && (not $job_uuid))
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { parameter => "job_uuid" }});
		$problem = 1;
	}
	
	# If I still don't have an job_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { job_uuid => $job_uuid }});
	if (not $job_uuid)
	{
		# It's possible that this is called before the host is recorded in the database. So to be
		# safe, we'll return without doing anything if there is no host_uuid in the database.
		my $hosts = $anvil->Database->get_hosts();
		my $found = 0;
		foreach my $hash_ref (@{$hosts})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"hash_ref->{host_uuid}" => $hash_ref->{host_uuid}, 
				"sys::host_uuid"        => $anvil->data->{sys}{host_uuid}, 
			}});
			if ($hash_ref->{host_uuid} eq $anvil->data->{sys}{host_uuid})
			{
				$found = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { found => $found }});
			}
		}
		if (not $found)
		{
			# We're out.
			return("");
		}
		
		# INSERT
		   $job_uuid = $anvil->Get->uuid();
		my $query    = "
INSERT INTO 
    jobs 
(
    job_uuid, 
    job_host_uuid, 
    job_command, 
    job_data, 
    job_picked_up_by, 
    job_picked_up_at, 
    job_updated, 
    job_name,
    job_progress, 
    job_title, 
    job_description, 
    job_status, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($job_uuid).", 
    ".$anvil->Database->quote($job_host_uuid).", 
    ".$anvil->Database->quote($job_command).", 
    ".$anvil->Database->quote($job_data).", 
    ".$anvil->Database->quote($job_picked_up_by).", 
    ".$anvil->Database->quote($job_picked_up_at).", 
    ".$anvil->Database->quote($job_updated).", 
    ".$anvil->Database->quote($job_name).", 
    ".$anvil->Database->quote($job_progress).", 
    ".$anvil->Database->quote($job_title).", 
    ".$anvil->Database->quote($job_description).", 
    ".$anvil->Database->quote($job_status).", 
    ".$anvil->Database->quote($anvil->Database->refresh_timestamp({debug => $debug}))."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    job_host_uuid, 
    job_command, 
    job_data, 
    job_picked_up_by, 
    job_picked_up_at, 
    job_updated, 
    job_name,
    job_progress, 
    job_title, 
    job_description, 
    job_status 
FROM 
    jobs 
WHERE 
    job_uuid = ".$anvil->Database->quote($job_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a job_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "job_uuid", uuid => $job_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_job_host_uuid    = $row->[0];
			my $old_job_command      = $row->[1];
			my $old_job_data         = $row->[2];
			my $old_job_picked_up_by = $row->[3];
			my $old_job_picked_up_at = $row->[4];
			my $old_job_updated      = $row->[5];
			my $old_job_name         = $row->[6];
			my $old_job_progress     = $row->[7];
			my $old_job_title        = $row->[8];
			my $old_job_description  = $row->[9];
			my $old_job_status       = $row->[10];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_job_host_uuid    => $old_job_host_uuid,
				old_job_command      => $old_job_command, 
				old_job_data         => $old_job_data, 
				old_job_picked_up_by => $old_job_picked_up_by, 
				old_job_picked_up_at => $old_job_picked_up_at, 
				old_job_updated      => $old_job_updated, 
				old_job_name         => $old_job_name, 
				old_job_progress     => $old_job_progress,
				old_job_title        => $old_job_title, 
				old_job_description  => $old_job_description, 
				old_job_status       => $old_job_status, 
			}});
			
			# Anything change?
			if ($update_progress_only)
			{
				# We'll conditionally check and update 'job_status', 'job_picked_up_by', 
				# 'job_picked_up_at' and 'job_data'.
				my $update = 0;
				my $query  = "
UPDATE 
    jobs 
SET ";
				if ($old_job_progress ne $job_progress)
				{
					$update =  1;
					$query  .= "
    job_progress     = ".$anvil->Database->quote($job_progress).", ";
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						update => $update, 
						query  => $query, 
					}});
				}
				if (($clear_status) or (($job_status ne "") && ($old_job_status ne $job_status)))
				{
					$update =  1;
					$query  .= "
    job_status       = ".$anvil->Database->quote($job_status).", ";
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						update => $update, 
						query  => $query, 
					}});
				}
				if (($job_picked_up_by ne "") && ($old_job_picked_up_by ne $job_picked_up_by))
				{
					$update =  1;
					$query  .= "
    job_picked_up_by = ".$anvil->Database->quote($job_picked_up_by).", ";
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						update => $update, 
						query  => $query, 
					}});
				}
				if (($job_picked_up_at ne "") && ($old_job_picked_up_at ne $job_picked_up_at))
				{
					$update =  1;
					$query  .= "
    job_picked_up_at = ".$anvil->Database->quote($job_picked_up_at).", ";
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						update => $update, 
						query  => $query, 
					}});
				}
				if (($job_data ne "") && ($old_job_data ne $job_data))
				{
					$update =  1;
					$query  .= "
    job_data         = ".$anvil->Database->quote($job_data).", ";
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						update => $update, 
						query  => $query, 
					}});
				}
				$query .= "
    modified_date    = ".$anvil->Database->quote($anvil->Database->refresh_timestamp({debug => $debug}))." 
WHERE 
    job_uuid         = ".$anvil->Database->quote($job_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					update => $update, 
					query  => $query, 
				}});
				if ($update)
				{
					# Something changed, update
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
			}
			else
			{
				if (($old_job_host_uuid    ne $job_host_uuid)    or 
				    ($old_job_command      ne $job_command)      or 
				    ($old_job_data         ne $job_data)         or 
				    ($old_job_picked_up_by ne $job_picked_up_by) or 
				    ($old_job_picked_up_at ne $job_picked_up_at) or 
				    ($old_job_updated      ne $job_updated)      or 
				    ($old_job_name         ne $job_name)         or 
				    ($old_job_progress     ne $job_progress)     or 
				    ($old_job_title        ne $job_title)        or 
				    ($old_job_description  ne $job_description)  or 
				    ($old_job_status       ne $job_status))
				{
					# Something changed, save. Before I do though, refresh the database 
					# timestamp as it's likely this isn't the only update that will 
					# happen on this pass.
					my $query = "
UPDATE 
    jobs 
SET 
    job_host_uuid    = ".$anvil->Database->quote($job_host_uuid).",  
    job_command      = ".$anvil->Database->quote($job_command).", 
    job_data         = ".$anvil->Database->quote($job_data).", 
    job_picked_up_by = ".$anvil->Database->quote($job_picked_up_by).", 
    job_picked_up_at = ".$anvil->Database->quote($job_picked_up_at).", 
    job_updated      = ".$anvil->Database->quote($job_updated).", 
    job_name         = ".$anvil->Database->quote($job_name).", 
    job_progress     = ".$anvil->Database->quote($job_progress).", 
    job_title        = ".$anvil->Database->quote($job_title).", 
    job_description  = ".$anvil->Database->quote($job_description).", 
    job_status       = ".$anvil->Database->quote($job_status).", 
    modified_date    = ".$anvil->Database->quote($anvil->Database->refresh_timestamp({debug => $debug}))." 
WHERE 
    job_uuid         = ".$anvil->Database->quote($job_uuid)." 
";
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
			}
		}
	}
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { job_uuid => $job_uuid }});
	return($job_uuid);
}


=head2 insert_or_update_mail_servers

This updates (or inserts) a record in the 'mail_servers' table. The C<< mail_server_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 delete (optional, default '0')

If set to C<< 1 >>, the associated mail server will be deleted. Specifically, the C<< mail_server_helo_domain >> is set to C<< DELETED >>.

When this is set, either C<< mail_server_uuid >> or C<< mail_server_address >> is required.

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 mail_server_address (required) 

This is the domain name or IP address of the mail server that alert emails will be forwarded to.

=head3 mail_server_authentication (optional, default 'normal_password')

This is the authentication method used to pass our password (or otherwise prove our identity) to the target mail server.

This can be set to anything you wish, but the expected values are;

* C<< normal_password >>
* C<< encrypted_password >>
* C<< kerberos_gssapi >> 
* C<< ntlm >>
* C<< tls_certificate >>
* C<< oauth2 >>

=head3 mail_server_helo_domain (optional, default is the local machine's domain name)

This is the string passed to the target mail server for the C<< HELO >> or C<< EHLO >> string. See C<< https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol#SMTP_transport_example >> for more information.

=head3 mail_server_password (optional)

If needed to authenticate, this is the password portion passed along with the C<< mail_server_username >>.

=head3 mail_server_port (optional, default depends on 'mail_server_security')

If set, this is the TCP port used when connecting to th mail server. If not set, the port is detemined based on the C<< mail_server_security >>. If it is C<< none >> or C<< starttls >>, the port is C<< 143 >>. if is it C<< ssl_tls >>, the port is C<< 993 >>. 

=head3 mail_server_security (optional)

This is the connection security used when establishing a connection to the mail server. 

This can be set to anything you wish, but the expected values are;

* C<< none >> (default port 143)
* C<< starttls >> (default port 143)
* C<< ssl_tls >> (default port 993)

B<< NOTE >> - If any other string is passed and C<< mail_server_port >> is not set, port C<< 143 >> will be used.

=head3 mail_server_username (optional)

If needed to authenticate, this is the user name portion passed along with the C<< mail_server_password >>.

=head3 mail_server_uuid (optional)

If set, this is the UUID that will be used to update a record in the database. If not set, it will be searched for by looking for a matching C<< mail_server_address >>.

=cut
sub insert_or_update_mail_servers
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_mail_servers()" }});
	
	my $delete                     = defined $parameter->{'delete'}                   ? $parameter->{'delete'}                   : 0;
	my $uuid                       = defined $parameter->{uuid}                       ? $parameter->{uuid}                       : "";
	my $file                       = defined $parameter->{file}                       ? $parameter->{file}                       : "";
	my $line                       = defined $parameter->{line}                       ? $parameter->{line}                       : "";
	my $mail_server_address        = defined $parameter->{mail_server_address}        ? $parameter->{mail_server_address}        : "";
	my $mail_server_authentication = defined $parameter->{mail_server_authentication} ? $parameter->{mail_server_authentication} : "normal_password";
	my $mail_server_helo_domain    = defined $parameter->{mail_server_helo_domain}    ? $parameter->{mail_server_helo_domain}    : "";
	my $mail_server_password       = defined $parameter->{mail_server_password}       ? $parameter->{mail_server_password}       : "";
	my $mail_server_port           = defined $parameter->{mail_server_port}           ? $parameter->{mail_server_port}           : "";
	my $mail_server_security       = defined $parameter->{mail_server_security}       ? $parameter->{mail_server_security}       : "none";
	my $mail_server_username       = defined $parameter->{mail_server_username}       ? $parameter->{mail_server_username}       : "";
	my $mail_server_uuid           = defined $parameter->{mail_server_uuid}           ? $parameter->{mail_server_uuid}           : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		'delete'                   => $delete, 
		uuid                       => $uuid, 
		file                       => $file, 
		line                       => $line, 
		mail_server_address        => $mail_server_address, 
		mail_server_authentication => $mail_server_authentication, 
		mail_server_helo_domain    => $mail_server_helo_domain, 
		mail_server_password       => $mail_server_password, 
		mail_server_port           => $mail_server_port, 
		mail_server_security       => $mail_server_security, 
		mail_server_username       => $mail_server_username, 
		mail_server_uuid           => $mail_server_uuid, 
	}});
	
	# Did we get a mail server name? 
	if ((not $mail_server_address) && (not $mail_server_uuid))
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_mail_servers()", parameter => "mail_server_address" }});
		return("");
	}
	
	if (not $mail_server_uuid)
	{
		# Can we find it using the mail server address?
		my $query = "
SELECT 
    mail_server_uuid 
FROM 
    mail_servers 
WHERE 
    mail_server_address = ".$anvil->Database->quote($mail_server_address)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$mail_server_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { mail_server_uuid => $mail_server_uuid }});
		}
	}
	
	if ($delete)
	{
		if (not $mail_server_uuid)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_mail_servers()", parameter => "mail_server_uuid" }});
			return("");
		}
		else
		{
			# Delete it
			my $query = "SELECT mail_server_helo_domain FROM mail_servers WHERE mail_server_uuid = ".$anvil->Database->quote($mail_server_uuid).";";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count, 
			}});
			if ($count)
			{
				my $old_mail_server_helo_domain = $results->[0]->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { old_mail_server_helo_domain => $old_mail_server_helo_domain }});
				
				if ($old_mail_server_helo_domain ne "DELETED")
				{
					my $query = "
UPDATE 
    mail_servers 
SET 
    mail_server_helo_domain = 'DELETED',
    modified_date           = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE 
    mail_server_uuid        = ".$anvil->Database->quote($mail_server_uuid)."
;";
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
				return($mail_server_uuid);
			}
			else
			{
				# Not found.
				return("");
			}
		}
	}
	
	# Fill some data
	if (not $mail_server_helo_domain)
	{
		$mail_server_helo_domain = $anvil->_domain_name();
		if (not $mail_server_helo_domain)
		{
			# Fall back on 'localdomain'
			$mail_server_helo_domain = "localdomain";
		}
	}
	if (not $mail_server_port)
	{
		$mail_server_port = 143;
		if ($mail_server_security eq "ssl_tls")
		{
			$mail_server_port = 993;
		}
	}
	
	# If I still don't have an mail_server_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { mail_server_uuid => $mail_server_uuid }});
	if (not $mail_server_uuid)
	{
		# INSERT
		$mail_server_uuid = $anvil->Get->uuid();
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { mail_server_uuid => $mail_server_uuid }});
		
		my $query = "
INSERT INTO 
    mail_servers 
(
    mail_server_uuid, 
    mail_server_address, 
    mail_server_authentication, 
    mail_server_helo_domain, 
    mail_server_password, 
    mail_server_port, 
    mail_server_security, 
    mail_server_username, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($mail_server_uuid).", 
    ".$anvil->Database->quote($mail_server_address).", 
    ".$anvil->Database->quote($mail_server_authentication).", 
    ".$anvil->Database->quote($mail_server_helo_domain).", 
    ".$anvil->Database->quote($mail_server_password).", 
    ".$anvil->Database->quote($mail_server_port).", 
    ".$anvil->Database->quote($mail_server_security).", 
    ".$anvil->Database->quote($mail_server_username).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    mail_server_address, 
    mail_server_authentication, 
    mail_server_helo_domain, 
    mail_server_password, 
    mail_server_port, 
    mail_server_security, 
    mail_server_username 
FROM 
    mail_servers 
WHERE 
    mail_server_uuid = ".$anvil->Database->quote($mail_server_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a mail_server_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "mail_server_uuid", uuid => $mail_server_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_mail_server_address        = $row->[0]; 
			my $old_mail_server_authentication = $row->[1];
			my $old_mail_server_helo_domain    = $row->[2]; 
			my $old_mail_server_password       = $row->[3]; 
			my $old_mail_server_port           = $row->[4]; 
			my $old_mail_server_security       = $row->[5]; 
			my $old_mail_server_username       = $row->[6];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_mail_server_address        => $old_mail_server_address, 
				old_mail_server_authentication => $old_mail_server_authentication,
				old_mail_server_helo_domain    => $old_mail_server_helo_domain, 
				old_mail_server_password       => $old_mail_server_password, 
				old_mail_server_port           => $old_mail_server_port, 
				old_mail_server_security       => $old_mail_server_security, 
				old_mail_server_username       => $old_mail_server_username, 
			}});
			
			# Anything change?
			if (($old_mail_server_address        ne $mail_server_address)        or 
			    ($old_mail_server_authentication ne $mail_server_authentication) or 
			    ($old_mail_server_helo_domain    ne $mail_server_helo_domain)    or  
			    ($old_mail_server_password       ne $mail_server_password)       or  
			    ($old_mail_server_port           ne $mail_server_port)           or  
			    ($old_mail_server_security       ne $mail_server_security)       or  
			    ($old_mail_server_username       ne $mail_server_username))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    mail_servers 
SET 
    mail_server_address        = ".$anvil->Database->quote($mail_server_address).", 
    mail_server_authentication = ".$anvil->Database->quote($mail_server_authentication).", 
    mail_server_helo_domain    = ".$anvil->Database->quote($mail_server_helo_domain).", 
    mail_server_password       = ".$anvil->Database->quote($mail_server_password).", 
    mail_server_port           = ".$anvil->Database->quote($mail_server_port).", 
    mail_server_security       = ".$anvil->Database->quote($mail_server_security).", 
    mail_server_username       = ".$anvil->Database->quote($mail_server_username).", 
    modified_date              = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    mail_server_uuid           = ".$anvil->Database->quote($mail_server_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	return($mail_server_uuid);
}


=head2 insert_or_update_manifests

This updates (or inserts) a record in the 'manifests' table. This table is used to the "manifests" used to create and repair Anvil! systems.

If there is an error, an empty string is returned. Otherwise, the record's UUID is returned.

Parameters;

=head3 delete (optional)

If set, the C<< manifest_note >> is set to C<< DELETED >>. When set to C<< 1 >>, only the C<<  >> is required

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 manifest_uuid (optional)

When set, this UUID is used to update an existing record. When not passed, the C<< manifest_name >> is used to search for a match. If found, the associated UUID is used and the record is updated. 

=head3 manifest_name (required)

This is the name of the manifest. Generally, this is the name of the Anvil! itself. It can be set to something more useful to the user, however.

=head3 manifest_last_ran (optional, default 0)

This is the unix time when the manifest was last used to (re)build an Anvil! system. If not passed, the value is not changed. If the manifest is new, this is set to C<< 0 >>.

=head3 manifest_xml (required)

This is the raw XML containing the manifest.

=head3 manifest_note (optional)

This is a free-form field for saving notes about the mnaifest. If this is set to C<< DELETED >>, it will be ignored in the web interface.

=cut
sub insert_or_update_manifests
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_manifests()" }});
	
	my $delete            = defined $parameter->{'delete'}          ? $parameter->{'delete'}          : 0;
	my $uuid              = defined $parameter->{uuid}              ? $parameter->{uuid}              : "";
	my $file              = defined $parameter->{file}              ? $parameter->{file}              : "";
	my $line              = defined $parameter->{line}              ? $parameter->{line}              : "";
	my $manifest_uuid     = defined $parameter->{manifest_uuid}     ? $parameter->{manifest_uuid}     : "";
	my $manifest_name     = defined $parameter->{manifest_name}     ? $parameter->{manifest_name}     : "";
	my $manifest_last_ran = defined $parameter->{manifest_last_ran} ? $parameter->{manifest_last_ran} : "";
	my $manifest_xml      = defined $parameter->{manifest_xml}      ? $parameter->{manifest_xml}      : "";
	my $manifest_note     = defined $parameter->{manifest_note}     ? $parameter->{manifest_note}     : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		'delete'          => $delete, 
		file              => $file, 
		line              => $line, 
		manifest_uuid     => $manifest_uuid, 
		manifest_name     => $manifest_name, 
		manifest_last_ran => $manifest_last_ran, 
		manifest_xml      => $manifest_xml, 
		manifest_note     => $manifest_note, 
	}});
	
	# INSERT, but make sure we have enough data first.
	if (not $delete)
	{
		if (not $manifest_xml)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_manifests()", parameter => "manifest_xml" }});
			return("");
		}
		if (not $manifest_name)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_manifests()", parameter => "manifest_name" }});
			return("");
		}
	}
	
	# If we don't have a network interface UUID, try to look one up using the MAC address
	if (not $manifest_uuid)
	{
		# See if I know this NIC by referencing it's MAC and name. The name is needed because virtual
		# devices can share the MAC with the real interface.
		my $query = "
SELECT 
    manifest_uuid, 
    manifest_last_ran 
FROM 
    manifests 
WHERE 
    manifest_name = ".$anvil->Database->quote($manifest_name)."
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count,
		}});
		if ($count)
		{
			# If we weren't passed a 'manifest_last_ran', load the old value here.
			$manifest_uuid     = $results->[0]->[0];
			$manifest_last_ran = $results->[0]->[1] if $manifest_last_ran eq "";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				manifest_uuid     => $manifest_uuid,
				manifest_last_ran => $manifest_last_ran, 
			}});
		}
		elsif ($manifest_last_ran eq "")
		{
			# This is a new manifest and 'manifest_last_ran' wasn't passed, so set it to 0.
			$manifest_last_ran = 0;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { manifest_last_ran => $manifest_last_ran }});
		}
	}
	
	if ($delete)
	{
		if (not $manifest_uuid)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_manifests()", parameter => "manifest_uuid" }});
			return("");
		}
		else
		{
			# Delete it
			my $query = "SELECT manifest_note FROM manifests WHERE manifest_uuid = ".$anvil->Database->quote($manifest_uuid).";";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count, 
			}});
			if ($count)
			{
				my $old_manifest_note = $results->[0]->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { old_manifest_note => $old_manifest_note }});
				
				if ($old_manifest_note ne "DELETED")
				{
					my $query = "
UPDATE 
    manifests 
SET 
    manifest_note = 'DELETED', 
    modified_date = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE 
    manifest_uuid = ".$anvil->Database->quote($manifest_uuid)."
;";
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
				return($manifest_uuid);
			}
			else
			{
				# Not found.
				return("");
			}
		}
	}
	
	# Now, if we're inserting or updating, we'll need to require different bits.
	if ($manifest_uuid)
	{
		# Update
		my $query = "
SELECT 
    manifest_name,
    manifest_last_ran, 
    manifest_xml, 
    manifest_note 
FROM 
    manifests 
WHERE 
    manifest_uuid = ".$anvil->Database->quote($manifest_uuid).";
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count,
		}});
		if (not $count)
		{
			# I have a manifest_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "manifest_uuid", uuid => $manifest_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_manifest_name     = $row->[0];
			my $old_manifest_last_ran = $row->[1];
			my $old_manifest_xml      = $row->[2];
			my $old_manifest_note     = $row->[3];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_manifest_name     => $old_manifest_name,
				old_manifest_last_ran => $old_manifest_last_ran,
				old_manifest_xml      => $old_manifest_xml,
				old_manifest_note     => $old_manifest_note, 
			}});
			
			# Anything to update? This is a little extra complicated because if a variable was
			# not passed in, we want to not compare it.
			if (($manifest_name     ne $old_manifest_name)     or 
			    ($manifest_last_ran ne $old_manifest_last_ran) or 
			    ($manifest_xml      ne $old_manifest_xml)      or 
			    ($manifest_note     ne $old_manifest_note))
			{
				# UPDATE any rows passed to us.
				my $query = "
UPDATE 
    manifests
SET 
    manifest_name     = ".$anvil->Database->quote($manifest_name).", 
    manifest_last_ran = ".$anvil->Database->quote($manifest_last_ran).", 
    manifest_xml      = ".$anvil->Database->quote($manifest_xml).", 
    manifest_note     = ".$anvil->Database->quote($manifest_note).", 
    modified_date     = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE
    manifest_uuid     = ".$anvil->Database->quote($manifest_uuid)."
;";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	else
	{
		# And INSERT
		$manifest_uuid = $anvil->Get->uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { manifest_uuid => $manifest_uuid }});
		
		my $query = "
INSERT INTO 
    manifests 
(
    manifest_uuid, 
    manifest_name, 
    manifest_last_ran, 
    manifest_xml, 
    manifest_note,  
    modified_date
) VALUES (
    ".$anvil->Database->quote($manifest_uuid).", 
    ".$anvil->Database->quote($manifest_name).", 
    ".$anvil->Database->quote($manifest_last_ran).", 
    ".$anvil->Database->quote($manifest_xml).", 
    ".$anvil->Database->quote($manifest_note).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0126", variables => { method => "Database->insert_or_update_network_interfaces()" }});
	return($manifest_uuid);
}


=head2 insert_or_update_network_interfaces

This updates (or inserts) a record in the 'interfaces' table. This table is used to store physical network interface information.

If there is an error, an empty string is returned. Otherwise, the record's UUID is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 link_only (optional, default '0')

If this is set to C<< 1 >>, only the C<< network_interface_name >>, C<< network_interface_link_state >>, C<< network_interface_mac_address >>, C<< network_interface_operational >> and C<< network_interface_speed >> are required and analyzed. Generally, C<< timestamp >> will also be passed as this parameter is generally used to flush out cached state changes.

B<< NOTE >>: This only works for existing records. If this is passed for an interface that is not previously known, it will be ignored and no C<< network_interface_uuid >> will be returned.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 delete (optional, default '0')

When set to C<< 1 >>, the C<< network_interface_operational >> is set to C<< DELETED >>, and nothing else is changed. When set, either C<< network_interface_uuid >> or C<< network_interface_mac_address >> and C<< network_interface_name >> are needed.

=head3 network_interface_bond_uuid (optional)

If this interface is part of a bond, this UUID will be the C<< bonds >> -> C<< bond_uuid >> that this interface is slaved to.

=head3 network_interface_bridge_uuid (optional)

If this interface is connected to a bridge, this is the C<< bridges >> -> C<< bridge_uuid >> of that bridge.

=head3 network_interface_duplex (optional)

This can be set to C<< full >>, C<< half >> or C<< unknown >>, with the later being the default.

=head3 network_interface_host_uuid (optional)

This is the host's UUID, as set in C<< sys::host_uuid >>. If not passed, the host's UUID will be read from the system.

=head3 network_interface_link_state (optional)

This can be set to C<< 0 >> or C<< 1 >>, with the later being the default. This indicates if a physical link is present.

=head3 network_interface_mac_address (required)

This is the MAC address of the interface.

=head3 network_interface_medium (required)

This is the medium the interface uses. This is generally C<< copper >>, C<< fiber >>, C<< radio >>, etc.

=head3 network_interface_mtu (optional)

This is the maximum transmit unit (MTU) that this interface supports, in bytes per second. This is usally C<< 1500 >>.

=head3 network_interface_name (required)

This is the current device name for this interface.

=head3 network_interface_operational (optional)

This can be set to C<< up >>, C<< down >> or C<< unknown >>, with the later being the default. This indicates whether the interface is active or not.

=head3 network_interface_speed (optional)

This is the current speed of the network interface in Mbps (megabits per second). If it is not passed, it is set to 0.

=head3 network_interface_uuid (optional)

This is the UUID of an existing record to be updated. If this is not passed, the UUID will be searched using the interface's MAC address. If no match is found, the record will be INSERTed and a new random UUID generated.

=head3 timestamp (optional, default 'sys::database::timestamp')

When C<< link_only >> is used, this can be set to use a different time stamp (used when writing cached records from disk).

=cut
sub insert_or_update_network_interfaces
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_network_interfaces()" }});
	
	my $delete                        = defined $parameter->{'delete'}                      ? $parameter->{'delete'}                      : 0;
	my $uuid                          = defined $parameter->{uuid}                          ? $parameter->{uuid}                          : "";
	my $file                          = defined $parameter->{file}                          ? $parameter->{file}                          : "";
	my $line                          = defined $parameter->{line}                          ? $parameter->{line}                          : "";
	my $link_only                     = defined $parameter->{link_only}                     ? $parameter->{link_only}                     : 0;
	my $network_interface_bond_uuid   =         $parameter->{network_interface_bond_uuid}   ? $parameter->{network_interface_bond_uuid}   : 'NULL';
	my $network_interface_bridge_uuid =         $parameter->{network_interface_bridge_uuid} ? $parameter->{network_interface_bridge_uuid} : 'NULL';
	my $network_interface_duplex      = defined $parameter->{network_interface_duplex}      ? $parameter->{network_interface_duplex}      : "unknown";
	my $network_interface_host_uuid   = defined $parameter->{network_interface_host_uuid}   ? $parameter->{network_interface_host_uuid}   : $anvil->Get->host_uuid;
	my $network_interface_link_state  = defined $parameter->{network_interface_link_state}  ? $parameter->{network_interface_link_state}  : "unknown";
	my $network_interface_operational = defined $parameter->{network_interface_operational} ? $parameter->{network_interface_operational} : "unknown";
	my $network_interface_mac_address = defined $parameter->{network_interface_mac_address} ? $parameter->{network_interface_mac_address} : "";
	my $network_interface_medium      = defined $parameter->{network_interface_medium}      ? $parameter->{network_interface_medium}      : "";
	my $network_interface_mtu         = defined $parameter->{network_interface_mtu}         ? $parameter->{network_interface_mtu}         : 0;
	my $network_interface_name        = defined $parameter->{network_interface_name}        ? $parameter->{network_interface_name}        : "";
	my $network_interface_speed       = defined $parameter->{network_interface_speed}       ? $parameter->{network_interface_speed}       : 0;
	my $network_interface_uuid        = defined $parameter->{network_interface_uuid}        ? $parameter->{interface_uuid}                : "";
	my $timestamp                     = defined $parameter->{timestamp}                     ? $parameter->{timestamp}                     : $anvil->data->{sys}{database}{timestamp};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		'delete'                      => $delete, 
		uuid                          => $uuid, 
		file                          => $file, 
		line                          => $line, 
		link_only                     => $link_only, 
		network_interface_bond_uuid   => $network_interface_bond_uuid, 
		network_interface_bridge_uuid => $network_interface_bridge_uuid, 
		network_interface_duplex      => $network_interface_duplex, 
		network_interface_host_uuid   => $network_interface_host_uuid, 
		network_interface_link_state  => $network_interface_link_state, 
		network_interface_operational => $network_interface_operational, 
		network_interface_mac_address => $network_interface_mac_address, 
		network_interface_medium      => $network_interface_medium, 
		network_interface_mtu         => $network_interface_mtu, 
		network_interface_name        => $network_interface_name,
		network_interface_speed       => $network_interface_speed, 
		network_interface_uuid        => $network_interface_uuid,
	}});
	
	# INSERT, but make sure we have enough data first.
	if (not $delete)
	{
		if (not $network_interface_mac_address)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_network_interfaces()", parameter => "network_interface_mac_address" }});
			return("");
		}
		else
		{
			# Always lower-case the MAC address.
			$network_interface_mac_address = lc($network_interface_mac_address);
		}
		if (not $network_interface_name)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_network_interfaces()", parameter => "network_interface_name" }});
			return("");
		}
		if (($network_interface_bond_uuid ne 'NULL') && (not $anvil->Validate->is_uuid({uuid => $network_interface_bond_uuid})))
		{
			# Bad UUID.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0130", variables => { method => "Database->insert_or_update_network_interfaces()", parameter => "network_interface_bond_uuid", uuid => $network_interface_bond_uuid }});
			return("");
		}
		if (($network_interface_bridge_uuid ne 'NULL') && (not $anvil->Validate->is_uuid({uuid => $network_interface_bridge_uuid})))
		{
			# Bad UUID.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0130", variables => { method => "Database->insert_or_update_network_interfaces()", parameter => "network_interface_bridge_uuid", uuid => $network_interface_bridge_uuid }});
			return("");
		}
	}
	
	# If we don't have a network interface UUID, try to look one up using the MAC address
	if (not $network_interface_uuid)
	{
		# See if I know this NIC by referencing it's MAC and name. The name is needed because virtual
		# devices can share the MAC with the real interface.
		my $query = "
SELECT 
    network_interface_uuid 
FROM 
    network_interfaces 
WHERE 
    network_interface_mac_address = ".$anvil->Database->quote($network_interface_mac_address)." 
AND 
    network_interface_name        = ".$anvil->Database->quote($network_interface_name)."
AND 
    network_interface_host_uuid   = ".$anvil->Database->quote($network_interface_host_uuid)."
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		$network_interface_uuid = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__})->[0]->[0];
		$network_interface_uuid = "" if not defined $network_interface_uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { network_interface_uuid => $network_interface_uuid }});
		
		if (($link_only) && (not $network_interface_uuid))
		{
			# Can't INSERT.
			return("");
		}
	}
	
	if ($delete)
	{
		if (not $network_interface_uuid)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_network_interfaces()", parameter => "network_interface_uuid" }});
			return("");
		}
		else
		{
			# Delete it
			my $query = "SELECT network_interface_operational FROM network_interfaces WHERE network_interface_uuid = ".$anvil->Database->quote($network_interface_uuid).";";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count, 
			}});
			if ($count)
			{
				my $old_network_interface_operational = $results->[0]->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { old_network_interface_operational => $old_network_interface_operational }});
				
				if ($old_network_interface_operational ne "DELETED")
				{
					my $query = "
UPDATE 
    network_interfaces 
SET 
    network_interface_operational = 'DELETED', 
    modified_date                 = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE 
    network_interface_uuid        = ".$anvil->Database->quote($network_interface_uuid)."
;";
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
				return($network_interface_uuid);
			}
			else
			{
				# Not found.
				return("");
			}
		}
	}
	
	# Now, if we're inserting or updating, we'll need to require different bits.
	if ($network_interface_uuid)
	{
		# Update
		my $query = "
SELECT 
    network_interface_host_uuid, 
    network_interface_mac_address, 
    network_interface_name,
    network_interface_speed, 
    network_interface_mtu, 
    network_interface_link_state, 
    network_interface_operational, 
    network_interface_duplex, 
    network_interface_medium, 
    network_interface_bond_uuid, 
    network_interface_bridge_uuid 
FROM 
    network_interfaces 
WHERE 
    network_interface_uuid = ".$anvil->Database->quote($network_interface_uuid).";
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count,
		}});
		if (not $count)
		{
			# I have a network_interface_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "network_interface_uuid", uuid => $network_interface_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_network_interface_host_uuid   =         $row->[0];
			my $old_network_interface_mac_address =         $row->[1];
			my $old_network_interface_name        =         $row->[2];
			my $old_network_interface_speed       =         $row->[3];
			my $old_network_interface_mtu         =         $row->[4];
			my $old_network_interface_link_state  =         $row->[5];
			my $old_network_interface_operational =         $row->[6];
			my $old_network_interface_duplex      =         $row->[7];
			my $old_network_interface_medium      =         $row->[8];
			my $old_network_interface_bond_uuid   = defined $row->[9]  ? $row->[9]  : 'NULL';
			my $old_network_interface_bridge_uuid = defined $row->[10] ? $row->[10] : 'NULL';
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_network_interface_host_uuid   => $old_network_interface_host_uuid,
				old_network_interface_mac_address => $old_network_interface_mac_address,
				old_network_interface_name        => $old_network_interface_name,
				old_network_interface_speed       => $old_network_interface_speed,
				old_network_interface_mtu         => $old_network_interface_mtu,
				old_network_interface_link_state  => $old_network_interface_link_state,
				old_network_interface_operational => $old_network_interface_operational, 
				old_network_interface_duplex      => $old_network_interface_duplex,
				old_network_interface_medium      => $old_network_interface_medium,
				old_network_interface_bond_uuid   => $old_network_interface_bond_uuid,
				old_network_interface_bridge_uuid => $old_network_interface_bridge_uuid,
			}});
			
			# If 'link_only' is set, we're only checking/updating a subset of values.
			if ($link_only)
			{
				if (($network_interface_name        ne $old_network_interface_name)        or 
				    ($network_interface_link_state  ne $old_network_interface_link_state)  or 
				    ($network_interface_operational ne $old_network_interface_operational) or 
				    ($network_interface_mac_address ne $old_network_interface_mac_address) or 
				    ($network_interface_speed       ne $old_network_interface_speed))
				{
					# Update.
					my $query = "
UPDATE 
    network_interfaces
SET 
    network_interface_host_uuid   = ".$anvil->Database->quote($network_interface_host_uuid).", 
    network_interface_name        = ".$anvil->Database->quote($network_interface_name).", 
    network_interface_link_state  = ".$anvil->Database->quote($network_interface_link_state).", 
    network_interface_operational = ".$anvil->Database->quote($network_interface_operational).", 
    network_interface_mac_address = ".$anvil->Database->quote($network_interface_mac_address).", 
    network_interface_speed       = ".$anvil->Database->quote($network_interface_speed).", 
    modified_date                 = ".$anvil->Database->quote($timestamp)." 
WHERE
    network_interface_uuid        = ".$anvil->Database->quote($network_interface_uuid)."
;";
					$query =~ s/'NULL'/NULL/g;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
					$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
				return($network_interface_uuid);
			}
			
			# Anything to update? This is a little extra complicated because if a variable was
			# not passed in, we want to not compare it.
			if (($network_interface_bond_uuid   ne $old_network_interface_bond_uuid)   or 
			    ($network_interface_bridge_uuid ne $old_network_interface_bridge_uuid) or 
			    ($network_interface_name        ne $old_network_interface_name)        or 
			    ($network_interface_duplex      ne $old_network_interface_duplex)      or 
			    ($network_interface_link_state  ne $old_network_interface_link_state)  or 
			    ($network_interface_operational ne $old_network_interface_operational) or 
			    ($network_interface_mac_address ne $old_network_interface_mac_address) or 
			    ($network_interface_medium      ne $old_network_interface_medium)      or 
			    ($network_interface_mtu         ne $old_network_interface_mtu)         or 
			    ($network_interface_speed       ne $old_network_interface_speed)       or
			    ($network_interface_host_uuid   ne $old_network_interface_host_uuid))
			{
				# UPDATE any rows passed to us.
				my $query = "
UPDATE 
    network_interfaces
SET 
    network_interface_host_uuid   = ".$anvil->Database->quote($network_interface_host_uuid).", 
    network_interface_bond_uuid   = ".$anvil->Database->quote($network_interface_bond_uuid).", 
    network_interface_bridge_uuid = ".$anvil->Database->quote($network_interface_bridge_uuid).", 
    network_interface_name        = ".$anvil->Database->quote($network_interface_name).", 
    network_interface_duplex      = ".$anvil->Database->quote($network_interface_duplex).", 
    network_interface_link_state  = ".$anvil->Database->quote($network_interface_link_state).", 
    network_interface_operational = ".$anvil->Database->quote($network_interface_operational).", 
    network_interface_mac_address = ".$anvil->Database->quote($network_interface_mac_address).", 
    network_interface_medium      = ".$anvil->Database->quote($network_interface_medium).", 
    network_interface_mtu         = ".$anvil->Database->quote($network_interface_mtu).", 
    network_interface_speed       = ".$anvil->Database->quote($network_interface_speed).", 
    modified_date                 = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE
    network_interface_uuid        = ".$anvil->Database->quote($network_interface_uuid)."
;";
				$query =~ s/'NULL'/NULL/g;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	else
	{
		# And INSERT
		$network_interface_uuid = $anvil->Get->uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { network_interface_uuid => $network_interface_uuid }});
		
		my $query = "
INSERT INTO 
    network_interfaces 
(
    network_interface_uuid, 
    network_interface_bond_uuid, 
    network_interface_bridge_uuid, 
    network_interface_name, 
    network_interface_duplex, 
    network_interface_host_uuid, 
    network_interface_link_state,
    network_interface_operational,  
    network_interface_mac_address, 
    network_interface_medium, 
    network_interface_mtu, 
    network_interface_speed, 
    modified_date
) VALUES (
    ".$anvil->Database->quote($network_interface_uuid).",  
    ".$anvil->Database->quote($network_interface_bond_uuid).", 
    ".$anvil->Database->quote($network_interface_bridge_uuid).", 
    ".$anvil->Database->quote($network_interface_name).", 
    ".$anvil->Database->quote($network_interface_duplex).", 
    ".$anvil->Database->quote($network_interface_host_uuid).", 
    ".$anvil->Database->quote($network_interface_link_state).", 
    ".$anvil->Database->quote($network_interface_operational).", 
    ".$anvil->Database->quote($network_interface_mac_address).", 
    ".$anvil->Database->quote($network_interface_medium).", 
    ".$anvil->Database->quote($network_interface_mtu).", 
    ".$anvil->Database->quote($network_interface_speed).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$query =~ s/'NULL'/NULL/g;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0126", variables => { method => "Database->insert_or_update_network_interfaces()" }});
	return($network_interface_uuid);
}


=head2 insert_or_update_notifications

This updates (or inserts) a record in the C<< notifications >> table used for configuring what recipients get what alerts for a given host.

If there is an error, an empty string is returned.

B<< NOTE >>: The information is this table IS NOT AUTHORITATIVE! It's generally updated daily, so the information here could be stale.

Parameters;

=head3 notification_uuid (optional)

If set, this is the specific entry that will be updated. 

=head3 notification_recipient_uuid (required)

This is the C<< recipients >> -> C<< recipient_uuid >> of the alert recipient.

=head3 notification_host_uuid (required)

This is the C<< hosts >> -> C<< host_uuid >> of the machine generating alerts.

=head3 notification_alert_level (required)

This is the alert level that the recipient is interested in. Any alert of equal or higher level will be sent to the associated recipient.

Valid values;

=head4 0 (ignore)

No alerts from the associated system will be sent to this recipient.

=head4 1 (critical)

Critical alerts. These are alerts that almost certainly indicate an issue with the system that has are likely will cause a service interruption. (ie: node was fenced, emergency shut down, etc)

=head4 2 (warning)

Warning alerts. These are alerts that likely require the attention of an administrator, but have not caused a service interruption. (ie: power loss/load shed, over/under voltage, fan failure, network link failure, etc)

=head4 3 (notice)

Notice alerts. These are generally low priority alerts that do not need attention, but might be indicators of developing problems. (ie: UPSes transfering to batteries, server migration/shut down/boot up, etc)

=cut
sub insert_or_update_notifications
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_notifications()" }});
	
	my $uuid                        = defined $parameter->{uuid}                        ? $parameter->{uuid}                        : "";
	my $file                        = defined $parameter->{file}                        ? $parameter->{file}                        : "";
	my $line                        = defined $parameter->{line}                        ? $parameter->{line}                        : "";
	my $notification_uuid           = defined $parameter->{notification_uuid}           ? $parameter->{notification_uuid}           : "";
	my $notification_recipient_uuid = defined $parameter->{notification_recipient_uuid} ? $parameter->{notification_recipient_uuid} : "";
	my $notification_host_uuid      = defined $parameter->{notification_host_uuid}      ? $parameter->{notification_host_uuid}      : "";
	my $notification_alert_level    = defined $parameter->{notification_alert_level}    ? $parameter->{notification_alert_level}    : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		notification_uuid           => $notification_uuid, 
		notification_recipient_uuid => $notification_recipient_uuid, 
		notification_host_uuid      => $notification_host_uuid, 
		notification_alert_level    => $notification_alert_level, 
	}});
	
	if (not $notification_recipient_uuid)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_notifications()", parameter => "notification_recipient_uuid" }});
		return("");
	}
	if (not $notification_host_uuid)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_notifications()", parameter => "notification_host_uuid" }});
		return("");
	}
	if ($notification_alert_level eq "")
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_notifications()", parameter => "notification_alert_level" }});
		return("");
	}
	elsif (($notification_alert_level =~ /\D/) or ($notification_alert_level < 0) or ($notification_alert_level > 3))
	{
		# Not an integer
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "error_0109", variables => { notification_alert_level => $notification_alert_level }});
		return("");
	}
	
	# If we don't have the notification_uuid, see if we can look it up.
	if (not $notification_uuid)
	{
		my $query = "
SELECT 
    notification_uuid 
FROM 
    notifications 
WHERE 
    notification_recipient_uuid = ".$anvil->Database->quote($notification_recipient_uuid)." 
AND 
    notification_host_uuid      = ".$anvil->Database->quote($notification_host_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$notification_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { notification_uuid => $notification_uuid }});
		}
	}
	
	# Do we have an existing entry?
	if ($notification_uuid)
	{
		# Yes, look up the previous notification_alert_level.
		my $query = "
SELECT 
    notification_alert_level 
FROM 
    notifications 
WHERE 
    notification_uuid = ".$anvil->Database->quote($notification_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		# If this doesn't return anything, the passed in UUID was invalid.
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# Error out.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "error_0110", variables => { notification_uuid => $notification_uuid }});
			return("");
		}
		my $old_notification_alert_level = $results->[0]->[0];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { old_notification_alert_level => $old_notification_alert_level }});
		
		# Did the level change?
		if ($notification_alert_level ne $old_notification_alert_level)
		{
			# UPDATE
			my $query = "
UPDATE 
    notifications 
SET 
    notification_alert_level = ".$anvil->Database->quote($notification_alert_level).", 
    modified_date            = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    notification_uuid        = ".$anvil->Database->quote($notification_uuid)." 
";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
			$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		}
	}
	else
	{
		# Nope, INSERT
		$notification_uuid = $anvil->Get->uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { notification_uuid => $notification_uuid }});
		
		my $query = "
INSERT INTO 
    notifications 
(
    notification_uuid, 
    notification_recipient_uuid, 
    notification_host_uuid, 
    notification_alert_level, 
    modified_date
) VALUES (
    ".$anvil->Database->quote($notification_uuid).",  
    ".$anvil->Database->quote($notification_recipient_uuid).",  
    ".$anvil->Database->quote($notification_host_uuid).",  
    ".$anvil->Database->quote($notification_alert_level).",  
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	
	return($notification_uuid)
}


=head2 insert_or_update_mac_to_ip

This updates (or inserts) a record in the C<< mac_to_ip >> table used for tracking what MAC addresses have what IP addresses.

If there is an error, an empty string is returned.

B<< NOTE >>: The information is this table IS NOT AUTHORITATIVE! It's generally updated daily, so the information here could be stale.

Parameters;

=head3 mac_to_ip_uuid (optional)

If passed, the column with that specific C<< mac_to_ip_uuid >> will be updated, if it exists.

=head3 mac_to_ip_ip_address (required)

This is the IP address seen in use by the associated C<< mac_to_ip_mac_address >>.

=head3 mac_to_ip_mac_address (required)

This is the MAC address associated with the IP in by C<< mac_to_ip_ip_address >>.

=head3 mac_to_ip_note (optional)

This is a free-form field to store information about the host (like the host name).

=head3 update_note (optional, default '1')

When set to C<< 0 >> and nothing was passed for C<< mac_to_ip_note >>, the note will not be changed if a note exists.

B<< NOTE >>: If C<< mac_to_ip_note >> is set, it will be updated regardless of this parameter.

=cut
sub insert_or_update_mac_to_ip
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_mac_to_ip()" }});
	
	my $uuid                  = defined $parameter->{uuid}                  ? $parameter->{uuid}                  : "";
	my $file                  = defined $parameter->{file}                  ? $parameter->{file}                  : "";
	my $line                  = defined $parameter->{line}                  ? $parameter->{line}                  : "";
	my $mac_to_ip_uuid        = defined $parameter->{mac_to_ip_uuid}        ? $parameter->{mac_to_ip_uuid}        : "";
	my $mac_to_ip_mac_address = defined $parameter->{mac_to_ip_mac_address} ? $parameter->{mac_to_ip_mac_address} : "";
	my $mac_to_ip_note        = defined $parameter->{mac_to_ip_note}        ? $parameter->{mac_to_ip_note}        : "";
	my $mac_to_ip_ip_address  = defined $parameter->{mac_to_ip_ip_address}  ? $parameter->{mac_to_ip_ip_address}  : "";
	my $update_note           = defined $parameter->{update_note}           ? $parameter->{update_note}           : 1;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                  => $uuid, 
		file                  => $file, 
		line                  => $line, 
		mac_to_ip_uuid        => $mac_to_ip_uuid, 
		mac_to_ip_mac_address => $mac_to_ip_mac_address, 
		mac_to_ip_note        => $mac_to_ip_note,
		mac_to_ip_ip_address  => $mac_to_ip_ip_address, 
		update_note           => $update_note, 
	}});
	
	if (not $mac_to_ip_mac_address)
	{
		# No user_uuid Throw an error and return.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_mac_to_ip()", parameter => "mac_to_ip_mac_address" }});
		return("");
	}
	if (not $mac_to_ip_ip_address)
	{
		# No user_uuid Throw an error and return.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_mac_to_ip()", parameter => "mac_to_ip_ip_address" }});
		return("");
	}
	
	# If the MAC isn't 12 or 17 bytes long (18 being xx:xx:xx:xx:xx:xx), or isn't a valid hex string, abort.
	if (((length($mac_to_ip_mac_address) != 12) && (length($mac_to_ip_mac_address) != 17)) or (not $anvil->Validate->is_hex({debug => $debug, string => $mac_to_ip_mac_address, sloppy => 1})))
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "error_0096", variables => { mac_to_ip_mac_address => $mac_to_ip_mac_address }});
		return("");
	}
	
	# If I don't have an mac_to_ip_uuid, try to find one.
	if (not $mac_to_ip_uuid)
	{
		my $query = "
SELECT 
    mac_to_ip_uuid 
FROM 
    mac_to_ip 
WHERE 
    mac_to_ip_mac_address = ".$anvil->Database->quote($mac_to_ip_mac_address)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$mac_to_ip_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { mac_to_ip_uuid => $mac_to_ip_uuid }});
		}
	}
	
	# If I have an mac_to_ip_uuid, see if an update is needed. If there still isn't an mac_to_ip_uuid, INSERT it.
	if ($mac_to_ip_uuid)
	{
		# Load the old data and see if anything has changed.
		my $query = "
SELECT 
    mac_to_ip_mac_address, 
    mac_to_ip_ip_address, 
    mac_to_ip_note 
FROM 
    mac_to_ip 
WHERE 
    mac_to_ip_uuid = ".$anvil->Database->quote($mac_to_ip_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a mac_to_ip_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "mac_to_ip_uuid", uuid => $mac_to_ip_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_mac_to_ip_mac_address = $row->[0];
			my $old_mac_to_ip_ip_address  = $row->[1];
			my $old_mac_to_ip_note        = $row->[2];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_mac_to_ip_mac_address => $old_mac_to_ip_mac_address, 
				old_mac_to_ip_ip_address  => $old_mac_to_ip_ip_address, 
				old_mac_to_ip_note        => $old_mac_to_ip_note, 
			}});
			
			my $include_note = 1;
			if ((not $update_note) && (not $mac_to_ip_note))
			{
				# Don't evaluate the note. Make the old note empty so it doesn't trigger an 
				# update below.
				$include_note        = 0;
				$old_mac_to_ip_note = "";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					include_note       => $include_note, 
					old_mac_to_ip_note => $old_mac_to_ip_note, 
				}});
			}
			
			# Anything change?
			if (($old_mac_to_ip_mac_address ne $mac_to_ip_mac_address) or 
			    ($old_mac_to_ip_ip_address  ne $mac_to_ip_ip_address)  or 
			    ($old_mac_to_ip_note        ne $mac_to_ip_note))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    mac_to_ip 
SET 
    mac_to_ip_mac_address = ".$anvil->Database->quote($mac_to_ip_mac_address).", 
    mac_to_ip_ip_address  = ".$anvil->Database->quote($mac_to_ip_ip_address).", ";
			if ($include_note)
			{
				$query .= "
    mac_to_ip_note        = ".$anvil->Database->quote($mac_to_ip_note).", ";
			}
			$query .= "
    modified_date         = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    mac_to_ip_uuid        = ".$anvil->Database->quote($mac_to_ip_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	else
	{
		# Save it.
		$mac_to_ip_uuid = $anvil->Get->uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { mac_to_ip_uuid => $mac_to_ip_uuid }});
		
		my $query = "
INSERT INTO 
    mac_to_ip 
(
    mac_to_ip_uuid, 
    mac_to_ip_mac_address, 
    mac_to_ip_ip_address, 
    mac_to_ip_note, 
    modified_date
) VALUES (
    ".$anvil->Database->quote($mac_to_ip_uuid).",  
    ".$anvil->Database->quote($mac_to_ip_mac_address).", 
    ".$anvil->Database->quote($mac_to_ip_ip_address).", 
    ".$anvil->Database->quote($mac_to_ip_note).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$query =~ s/'NULL'/NULL/g;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	
	return($mac_to_ip_uuid);
}


=head2 insert_or_update_oui

This updates (or inserts) a record in the C<< oui >> (Organizationally Unique Identifier) table used for converting network MAC addresses to the company that owns it. The C<< oui_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

B<< NOTE >>: This is one of the rare tables that doesn't have an owning host UUID.

Parameters;

=head3 oui_uuid (optional)

If passed, the column with that specific C<< oui_uuid >> will be updated, if it exists.

=head3 oui_mac_prefix (required)

This is the first 6 bytes of the MAC address owned by C<< oui_company_name >>.

=head3 oui_company_address (optional)

This is the registered address of the company that owns the OUI.

=head3 oui_company_name (required)

This is the name of the company that owns the C<< oui_mac_prefix >>.

=cut
sub insert_or_update_oui
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_oui()" }});
	
	my $uuid                = defined $parameter->{uuid}                ? $parameter->{uuid}                : "";
	my $file                = defined $parameter->{file}                ? $parameter->{file}                : "";
	my $line                = defined $parameter->{line}                ? $parameter->{line}                : "";
	my $oui_uuid            = defined $parameter->{oui_uuid}            ? $parameter->{oui_uuid}            : "";
	my $oui_mac_prefix      = defined $parameter->{oui_mac_prefix}      ? $parameter->{oui_mac_prefix}      : "";
	my $oui_company_address = defined $parameter->{oui_company_address} ? $parameter->{oui_company_address} : "";
	my $oui_company_name    = defined $parameter->{oui_company_name}    ? $parameter->{oui_company_name}    : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                => $uuid, 
		file                => $file, 
		line                => $line, 
		oui_uuid            => $oui_uuid, 
		oui_mac_prefix      => $oui_mac_prefix, 
		oui_company_address => $oui_company_address,
		oui_company_name    => $oui_company_name, 
	}});
	
	if (not $oui_mac_prefix)
	{
		# No user_uuid Throw an error and return.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_oui()", parameter => "oui_mac_prefix" }});
		return("");
	}
	if (not $oui_company_name)
	{
		# No user_uuid Throw an error and return.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_oui()", parameter => "oui_company_name" }});
		return("");
	}
	
	# If the MAC isn't 6 or 8 bytes long (8 being xx:xx:xx), or isn't a valid hex string, abort.
	if (((length($oui_mac_prefix) != 6) && (length($oui_mac_prefix) != 8)) or (not $anvil->Validate->is_hex({debug => $debug, string => $oui_mac_prefix, sloppy => 1})))
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "error_0096", variables => { oui_mac_prefix => $oui_mac_prefix }});
		return("");
	}
	
	# If I don't have an oui_uuid, try to find one.
	if (not $oui_uuid)
	{
		my $query = "
SELECT 
    oui_uuid 
FROM 
    oui 
WHERE 
    oui_mac_prefix = ".$anvil->Database->quote($oui_mac_prefix)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$oui_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { oui_uuid => $oui_uuid }});
		}
	}
	
	# If I have an oui_uuid, see if an update is needed. If there still isn't an oui_uuid, INSERT it.
	if ($oui_uuid)
	{
		# Load the old data and see if anything has changed.
		my $query = "
SELECT 
    oui_mac_prefix, 
    oui_company_address, 
    oui_company_name 
FROM 
    oui 
WHERE 
    oui_uuid = ".$anvil->Database->quote($oui_uuid)."
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a oui_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "oui_uuid", uuid => $oui_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_oui_mac_prefix      = $row->[0];
			my $old_oui_company_address = $row->[1];
			my $old_oui_company_name    = $row->[2];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_oui_mac_prefix      => $old_oui_mac_prefix, 
				old_oui_company_address => $old_oui_company_address, 
				old_oui_company_name    => $old_oui_company_name, 
			}});
			
			# Anything change?
			if (($old_oui_mac_prefix      ne $oui_mac_prefix)      or 
			    ($old_oui_company_address ne $oui_company_address) or 
			    ($old_oui_company_name    ne $oui_company_name))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    oui 
SET 
    oui_mac_prefix      = ".$anvil->Database->quote($oui_mac_prefix).", 
    oui_company_address = ".$anvil->Database->quote($oui_company_address).", 
    oui_company_name    = ".$anvil->Database->quote($oui_company_name).", 
    modified_date       = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    oui_uuid            = ".$anvil->Database->quote($oui_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	else
	{
		# Save it.
		$oui_uuid = $anvil->Get->uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { oui_uuid => $oui_uuid }});
		
		my $query = "
INSERT INTO 
    oui 
(
    oui_uuid, 
    oui_mac_prefix, 
    oui_company_address, 
    oui_company_name, 
    modified_date
) VALUES (
    ".$anvil->Database->quote($oui_uuid).",  
    ".$anvil->Database->quote($oui_mac_prefix).", 
    ".$anvil->Database->quote($oui_company_address).", 
    ".$anvil->Database->quote($oui_company_name).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$query =~ s/'NULL'/NULL/g;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	
	return($oui_uuid);
}


=head2 insert_or_update_recipients

This updates (or inserts) a record in the 'recipients' table. The C<< recipient_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 delete (optional, default '0')

If set to C<< 1 >>, the associated mail server will be deleted. Specifically, the C<< recipient_name >> is set to C<< DELETED >>.

When this is set, either C<< recipient_uuid >> or C<< recipient_email >> is required.

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 recipient_email (required)

This is the email address of the recipient. This is where alerts are sent to and as such, must be a valid email address.

=head3 recipient_language (optional, default 'en_CA')

This is the language that alert emails are crafted using for this recipient. This is the ISO language code, as set in the C<< <language name="en_CA" ... > >> element of the C<< words.xml >> file. If the preferred language is not available, the system language will be used in stead.

=head3 recipient_name (required)

This is the name of the recipient, and is used when crafting the email body and reply-to lists. 

=head3 recipient_new_level (optional, default '2')

When adding a new Anvil! to the system, the recipient will automatically start monitoring the new Anvil! using this alert level. This can be set to C<< 0 >> to prevent auto-monitoring of new systems.

Valid values;

=head4 0 (ignore)

None, ignore new systems

=head4 1 (critical)

Critical alerts. These are alerts that almost certainly indicate an issue with the system that has are likely will cause a service interruption. (ie: node was fenced, emergency shut down, etc)

=head4 2 (warning)

Warning alerts. These are alerts that likely require the attention of an administrator, but have not caused a service interruption. (ie: power loss/load shed, over/under voltage, fan failure, network link failure, etc)

=head4 3 (notice)

Notice alerts. These are generally low priority alerts that do not need attention, but might be indicators of developing problems. (ie: UPSes transfering to batteries, server migration/shut down/boot up, etc)

=head3 recipient_units (optional, default 'metric')

This can be set to 'imperial' if the user wants to receive values in imperial units. Currently, this causes temperatures to be returned in C<< °F >> instead of C<< °C >>.

=head3 recipient_uuid (optional)

If set, this is the UUID that will be used to update a record in the database. If not set, it will be searched for by looking for a matching C<< recipient_email >>.

=cut
sub insert_or_update_recipients
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_recipients()" }});
	
	my $delete              = defined $parameter->{'delete'}            ? $parameter->{'delete'}            : 0;
	my $uuid                = defined $parameter->{uuid}                ? $parameter->{uuid}                : "";
	my $file                = defined $parameter->{file}                ? $parameter->{file}                : "";
	my $line                = defined $parameter->{line}                ? $parameter->{line}                : "";
	my $recipient_email     = defined $parameter->{recipient_email}     ? $parameter->{recipient_email}     : "";
	my $recipient_language  = defined $parameter->{recipient_language}  ? $parameter->{recipient_language}  : "en_CA";
	my $recipient_name      = defined $parameter->{recipient_name}      ? $parameter->{recipient_name}      : "";
	my $recipient_new_level = defined $parameter->{recipient_new_level} ? $parameter->{recipient_new_level} : "2";
	my $recipient_units     = defined $parameter->{recipient_units}     ? $parameter->{recipient_units}     : "metric";
	my $recipient_uuid      = defined $parameter->{recipient_uuid}      ? $parameter->{recipient_uuid}      : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		'delete'            => $delete, 
		uuid                => $uuid, 
		file                => $file, 
		line                => $line, 
		recipient_email     => $recipient_email, 
		recipient_language  => $recipient_language, 
		recipient_name      => $recipient_name, 
		recipient_new_level => $recipient_new_level, 
		recipient_units     => $recipient_units, 
		recipient_uuid      => $recipient_uuid, 
	}});
	
	# Did we get a mail server name? 
	if ((not $recipient_email) && (not $recipient_uuid))
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_recipients()", parameter => "recipient_email" }});
		return("");
	}
	
	# Make sure the recipient_new_level is 0, 1, 2 or 3
	if (($recipient_new_level ne "0") && ($recipient_new_level ne "1") && ($recipient_new_level ne "2") && ($recipient_new_level ne "3"))
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "error_0108", variables => { recipient_new_level => $recipient_new_level }});
		return("");
	}
	
	if (not $recipient_uuid)
	{
		# Can we find it using the mail server address?
		my $query = "
SELECT 
    recipient_uuid 
FROM 
    recipients 
WHERE 
    recipient_email = ".$anvil->Database->quote($recipient_email)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$recipient_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { recipient_uuid => $recipient_uuid }});
		}
	}
	
	if ($delete)
	{
		if (not $recipient_uuid)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_recipients()", parameter => "recipient_uuid" }});
			return("");
		}
		else
		{
			# Delete it
			my $query = "SELECT recipient_name FROM recipients WHERE recipient_uuid = ".$anvil->Database->quote($recipient_uuid).";";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count, 
			}});
			if ($count)
			{
				my $old_recipient_name = $results->[0]->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { old_recipient_name => $old_recipient_name }});
				
				if ($old_recipient_name ne "DELETED")
				{
					my $query = "
UPDATE 
    recipients 
SET 
    recipient_name = 'DELETED', 
    modified_date  = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE 
    recipient_uuid = ".$anvil->Database->quote($recipient_uuid)."
;";
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
				return($recipient_uuid);
			}
			else
			{
				# Not found.
				return("");
			}
		}
	}
	
	# If we're here and we still don't have a recipient name, there's a problem.
	if (not $recipient_name)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_recipients()", parameter => "recipient_name" }});
		return("");
	}
	
	# If I still don't have an recipient_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { recipient_uuid => $recipient_uuid }});
	if (not $recipient_uuid)
	{
		# INSERT
		$recipient_uuid = $anvil->Get->uuid();
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { recipient_uuid => $recipient_uuid }});
		
		my $query = "
INSERT INTO 
    recipients 
(
    recipient_uuid, 
    recipient_email, 
    recipient_language, 
    recipient_name, 
    recipient_new_level, 
    recipient_units, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($recipient_uuid).", 
    ".$anvil->Database->quote($recipient_email).", 
    ".$anvil->Database->quote($recipient_language).", 
    ".$anvil->Database->quote($recipient_name).", 
    ".$anvil->Database->quote($recipient_new_level).", 
    ".$anvil->Database->quote($recipient_units).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    recipient_email, 
    recipient_language, 
    recipient_name, 
    recipient_new_level, 
    recipient_units 
FROM 
    recipients 
WHERE 
    recipient_uuid = ".$anvil->Database->quote($recipient_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a recipient_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "recipient_uuid", uuid => $recipient_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_recipient_email     = $row->[0]; 
			my $old_recipient_language  = $row->[1];
			my $old_recipient_name      = $row->[2]; 
			my $old_recipient_new_level = $row->[3]; 
			my $old_recipient_units     = $row->[4]; 
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_recipient_email     => $old_recipient_email, 
				old_recipient_language  => $old_recipient_language,
				old_recipient_name      => $old_recipient_name, 
				old_recipient_new_level => $old_recipient_new_level, 
				old_recipient_units     => $old_recipient_units, 
			}});
			
			# Anything change?
			if (($old_recipient_email     ne $recipient_email)     or 
			    ($old_recipient_language  ne $recipient_language)  or 
			    ($old_recipient_name      ne $recipient_name)      or  
			    ($old_recipient_new_level ne $recipient_new_level) or  
			    ($old_recipient_units     ne $recipient_units))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    recipients 
SET 
    recipient_email     = ".$anvil->Database->quote($recipient_email).", 
    recipient_language  = ".$anvil->Database->quote($recipient_language).", 
    recipient_name      = ".$anvil->Database->quote($recipient_name).", 
    recipient_new_level = ".$anvil->Database->quote($recipient_new_level).", 
    recipient_units     = ".$anvil->Database->quote($recipient_units).", 
    modified_date       = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    recipient_uuid      = ".$anvil->Database->quote($recipient_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	return($recipient_uuid);
}


=head2 insert_or_update_sessions

This updates (or inserts) a record in the 'sessions' table. The C<< session_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 session_uuid (optional)

If passed, the column with that specific C<< session_uuid >> will be updated, if it exists.

=head3 session_host_uuid (optional, default Get->host_uuid)

This is the host connected to the user's session.

=head3 session_user_uuid (optional, default 'cookie::anvil_user_uuid')

This is the user whose session is being manipulated. If this is not passed and C<< cookie::anvil_user_uuid >> is not set, this method will fail and return an empty string. This is only optional in so far as, most times, the appropriate cookie data is available.

=head3 session_salt (optional)

The session salt is appended to a session hash stored on the user's browser and used to authenticate a user session. If this is not passed, the existing salt will be removed, effectively (and literally) logging the user out of the host.

=head3 session_user_agent (optional, default '$ENV{HTTP_USER_AGENT})

This is the browser user agent string to record. If nothing is passed, and the C<< HTTP_USER_AGENT >> environment variable is set, that is used. 

=cut 
sub insert_or_update_sessions
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_sessions()" }});
	
	my $uuid               = defined $parameter->{uuid}               ? $parameter->{uuid}               : "";
	my $file               = defined $parameter->{file}               ? $parameter->{file}               : "";
	my $line               = defined $parameter->{line}               ? $parameter->{line}               : "";
	my $session_uuid       = defined $parameter->{session_uuid}       ? $parameter->{session_uuid}       : "";
	my $session_host_uuid  = defined $parameter->{session_host_uuid}  ? $parameter->{session_host_uuid}  : $anvil->Get->host_uuid;
	my $session_user_uuid  = defined $parameter->{session_user_uuid}  ? $parameter->{session_user_uuid}  : $anvil->data->{cookie}{anvil_user_uuid};
	my $session_salt       = defined $parameter->{session_salt}       ? $parameter->{session_salt}       : "";
	my $session_user_agent = defined $parameter->{session_user_agent} ? $parameter->{session_user_agent} : $ENV{HTTP_USER_AGENT};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid               => $uuid, 
		file               => $file, 
		line               => $line, 
		session_uuid       => $session_uuid, 
		session_host_uuid  => $session_host_uuid, 
		session_user_uuid  => $session_user_uuid, 
		session_salt       => $session_salt, 
		session_user_agent => $session_user_agent, 
	}});
	
	if (not $session_user_uuid)
	{
		# No user_uuid Throw an error and return.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_sessions()", parameter => "session_user_uuid" }});
		return("");
	}
	
	# If we don't have a session UUID, look for one using the host and user UUID.
	if (not $session_uuid)
	{
		my $query = "
SELECT 
    session_uuid 
FROM 
    sessions 
WHERE 
    session_user_uuid = ".$anvil->Database->quote($session_user_uuid)." 
AND 
    session_host_uuid = ".$anvil->Database->quote($session_host_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$session_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { session_uuid => $session_uuid }});
		}
	}
	
	# If we have a session UUID, check for changes before updating. If we still don't have a session 
	# UUID, we're INSERT'ing.
	if ($session_uuid)
	{
		# Read back the old data
		my $query = "
SELECT 
    session_host_uuid, 
    session_user_uuid, 
    session_salt, 
    session_user_agent 
FROM 
    sessions 
WHERE 
    session_uuid = ".$anvil->Database->quote($session_uuid)."
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a session_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "session_uuid", uuid => $session_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_session_host_uuid  =         $row->[0];
			my $old_session_user_uuid  =         $row->[1];
			my $old_session_salt       =         $row->[2];
			my $old_session_user_agent = defined $row->[3] ? $row->[3] : "";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_session_host_uuid  => $old_session_host_uuid, 
				old_session_user_uuid  => $old_session_user_uuid, 
				old_session_salt       => $old_session_salt, 
				old_session_user_agent => $old_session_user_agent, 
			}});
			
			# Anything change?
			if (($old_session_host_uuid  ne $session_host_uuid) or 
			    ($old_session_user_uuid  ne $session_user_uuid) or 
			    ($old_session_salt       ne $session_salt)      or 
			    ($old_session_user_agent ne $session_user_agent))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    sessions 
SET 
    session_host_uuid  = ".$anvil->Database->quote($session_host_uuid).",  
    session_user_uuid  = ".$anvil->Database->quote($session_user_uuid).", 
    session_salt       = ".$anvil->Database->quote($session_salt).", 
    session_user_agent = ".$anvil->Database->quote($session_user_agent).", 
    modified_date      = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    session_uuid       = ".$anvil->Database->quote($session_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	else
	{
		$session_uuid = $anvil->Get->uuid;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { session_uuid => $session_uuid }});
		
		my $query = "
INSERT INTO 
    sessions 
(
    session_uuid, 
    session_host_uuid, 
    session_user_uuid, 
    session_salt, 
    session_user_agent, 
    modified_date
) VALUES (
    ".$anvil->Database->quote($session_uuid).",  
    ".$anvil->Database->quote($session_host_uuid).", 
    ".$anvil->Database->quote($session_user_uuid).", 
    ".$anvil->Database->quote($session_salt).", 
    ".$anvil->Database->quote($session_user_agent).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$query =~ s/'NULL'/NULL/g;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	
	return($session_uuid);
}


=head2 insert_or_update_states

This updates (or inserts) a record in the 'states' table. The C<< state_uuid >> referencing the database row will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 state_uuid (optional)

This is the C<< state_uuid >> to update. If it is not specified but the C<< state_name >> is, a check will be made to see if an entry already exists. If so, that row will be UPDATEd. If not, a random UUID will be generated and a new entry will be INSERTed.

=head3 state_name (required)

This is the C<< state_name >> to INSERT or UPDATE. If a C<< state_uuid >> is passed, then the C<< state_name >> can be changed.

=head3 state_host_uuid (optional)

This is the host's UUID that this state entry belongs to. If not passed, C<< sys::host_uuid >> will be used.

=head3 state_note (optional)

This is an optional note related to this state entry.

=cut 
sub insert_or_update_states
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_states()" }});
	
	my $uuid            = defined $parameter->{uuid}            ? $parameter->{uuid}            : "";
	my $file            = defined $parameter->{file}            ? $parameter->{file}            : "";
	my $line            = defined $parameter->{line}            ? $parameter->{line}            : "";
	my $state_uuid      = defined $parameter->{state_uuid}      ? $parameter->{state_uuid}      : "";
	my $state_name      = defined $parameter->{state_name}      ? $parameter->{state_name}      : "";
	my $state_host_uuid = defined $parameter->{state_host_uuid} ? $parameter->{state_host_uuid} : $anvil->data->{sys}{host_uuid};
	my $state_note      = defined $parameter->{state_note}      ? $parameter->{state_note}      : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid            => $uuid, 
		file            => $file, 
		line            => $line, 
		state_uuid      => $state_uuid, 
		state_name      => $state_name, 
		state_host_uuid => $state_host_uuid, 
		state_note      => $state_note, 
	}});
	
	# If we were passed a database UUID, check for the open handle.
	if ($uuid)
	{
		$anvil->data->{cache}{database_handle}{$uuid} = "" if not defined $anvil->data->{cache}{database_handle}{$uuid};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"cache::database_handle::${uuid}" => $anvil->data->{cache}{database_handle}{$uuid}, 
		}});
	}
	
	if (not $state_name)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_states()", parameter => "state_name" }});
		return("");
	}
	if (not $state_host_uuid)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0108"});
		return("");
	}
	
	# If we don't have a UUID, see if we can find one for the given state server name.
	if (not $state_uuid)
	{
		my $query = "
SELECT 
    state_uuid 
FROM 
    states 
WHERE 
    state_name      = ".$anvil->Database->quote($state_name)." 
AND 
    state_host_uuid = ".$anvil->Database->quote($state_host_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		foreach my $row (@{$results})
		{
			$state_uuid = $row->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { state_uuid => $state_uuid }});
		}
	}
	
	# If I still don't have an state_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { state_uuid => $state_uuid }});
	if (not $state_uuid)
	{
		# It's possible that this is called before the host is recorded in the database. So to be
		# safe, we'll return without doing anything if there is no host_uuid in the database.
		my $hosts = $anvil->Database->get_hosts();
		my $found = 0;
		foreach my $hash_ref (@{$hosts})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"hash_ref->{host_uuid}" => $hash_ref->{host_uuid}, 
				"sys::host_uuid"        => $anvil->data->{sys}{host_uuid}, 
			}});
			if ($hash_ref->{host_uuid} eq $anvil->data->{sys}{host_uuid})
			{
				$found = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { found => $found }});
			}
		}
		if (not $found)
		{
			# We're out.
			return("");
		}
		
		# INSERT
		   $state_uuid = $anvil->Get->uuid();
		my $query      = "
INSERT INTO 
    states 
(
    state_uuid, 
    state_name,
    state_host_uuid, 
    state_note, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($state_uuid).", 
    ".$anvil->Database->quote($state_name).", 
    ".$anvil->Database->quote($state_host_uuid).", 
    ".$anvil->Database->quote($state_note).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    state_name,
    state_host_uuid, 
    state_note 
FROM 
    states 
WHERE 
    state_uuid = ".$anvil->Database->quote($state_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a state_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "state_uuid", uuid => $state_uuid }});
			return("");
		}
	
		foreach my $row (@{$results})
		{
			my $old_state_name         = $row->[0];
			my $old_state_host_uuid    = $row->[1];
			my $old_state_note         = $row->[2];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_state_name      => $old_state_name, 
				old_state_host_uuid => $old_state_host_uuid, 
				old_state_note      => $old_state_note, 
			}});
			
			# Anything change?
			if (($old_state_name      ne $state_name)      or 
			    ($old_state_host_uuid ne $state_host_uuid) or 
			    ($old_state_note      ne $state_note))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    states 
SET 
    state_name       = ".$anvil->Database->quote($state_name).", 
    state_host_uuid  = ".$anvil->Database->quote($state_host_uuid).",  
    state_note       = ".$anvil->Database->quote($state_note).", 
    modified_date    = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    state_uuid       = ".$anvil->Database->quote($state_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { state_uuid => $state_uuid }});
	return($state_uuid);
}


=head2 insert_or_update_upses

This updates (or inserts) a record in the 'upses' table. The C<< ups_uuid >> UUID will be returned.

If there is an error, an empty string is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 ups_agent (required)

This is the name of the ups agent to use when communicating with this ups device. The agent must be installed on any machine that may need to ups (or check the ups/power state of) a node.

=head3 ups_ip_address (optional, but generally required in practice)

This is the string that tells machines how to communicate / control the the ups device. This is used when configuring pacemaker's stonith (fencing). 

The exact formatting needs to match the STDIN parameters supported by C<< ups_agent >>. Please see C<< STDIN PARAMETERS >> section of the ups agent man page for this device.

For example, this can be set to:

* C<< ip="10.201.11.1" lanplus="1" username="admin" password="super secret password" 

B<< NOTES >>: 
* If C<< password_script >> is used, it is required that the user has copied the script to the nodes.
* Do not use C<< action="..." >> or the ups agent name. If either is found in the string, they will be ignored.
* Do not use C<< delay >>. It will be determined automatically based on which node has the most servers running on it.
* If this is set to C<< DELETED >>, the ups device is considered no longer used and it will be ignored by C<< Database->get_upses() >>.

=head3 ups_name (required)

This is the name of the ups device. Genreally, this is the short host name of the device.

=head3 ups_uuid (required)

The default value is the ups's UUID. When passed, the specific record is updated.

=cut
sub insert_or_update_upses
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_upses()" }});
	
	my $uuid           = defined $parameter->{uuid}           ? $parameter->{uuid}           : "";
	my $file           = defined $parameter->{file}           ? $parameter->{file}           : "";
	my $line           = defined $parameter->{line}           ? $parameter->{line}           : "";
	my $ups_agent      = defined $parameter->{ups_agent}      ? $parameter->{ups_agent}      : "";
	my $ups_ip_address = defined $parameter->{ups_ip_address} ? $parameter->{ups_ip_address} : "";
	my $ups_name       = defined $parameter->{ups_name}       ? $parameter->{ups_name}       : "";
	my $ups_uuid       = defined $parameter->{ups_uuid}       ? $parameter->{ups_uuid}       : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid           => $uuid, 
		file           => $file, 
		line           => $line, 
		ups_agent      => $ups_agent, 
		ups_ip_address => $ups_ip_address =~ /passwork=/ ? $anvil->Log->is_secure($ups_ip_address) : $ups_ip_address, 
		ups_name       => $ups_name, 
		ups_uuid       => $ups_uuid, 
	}});
	
	if (not $ups_agent)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_upses()", parameter => "ups_agent" }});
		return("");
	}
	if (not $ups_name)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_upses()", parameter => "ups_name" }});
		return("");
	}
	if (not $ups_ip_address)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_upses()", parameter => "ups_ip_address" }});
		return("");
	}
	
	# Do we have a UUID?
	if (not $ups_uuid)
	{
		### TODO: We might want to try finding it by the IP address, if the name doesn't match. This 
		###       might cause issues though if different UPSes spanning different BCNs could be 
		###       confused, perhaps?
		my $query = "
SELECT 
    ups_uuid 
FROM 
    upses 
WHERE 
    ups_name = ".$anvil->Database->quote($ups_name)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if ($count)
		{
			$ups_uuid = $results->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { ups_uuid => $ups_uuid }});
		}
	}
	
	# Do we have a UUID?
	if ($ups_uuid)
	{
		# Yup. Has something changed?
		my $query = "
SELECT 
    ups_agent, 
    ups_name, 
    ups_ip_address  
FROM 
    upses 
WHERE 
    ups_uuid = ".$anvil->Database->quote($ups_uuid)."
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count,
		}});
		foreach my $row (@{$results})
		{
			my $old_ups_agent     = $row->[0];
			my $old_ups_name      = $row->[1];
			my $old_ups_ip_address = $row->[2];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => {
				old_ups_agent     => $old_ups_agent,
				old_ups_name      => $old_ups_name =~ /passw/ ? $anvil->Log->is_secure($old_ups_name) : $old_ups_name, 
				old_ups_ip_address => $old_ups_ip_address, 
			}});
			if (($old_ups_agent     ne $ups_agent) or 
			    ($old_ups_name      ne $ups_name)  or 
			    ($old_ups_ip_address ne $ups_ip_address))
			{
				# Clear the stop data.
				my $query = "
UPDATE 
    upses
SET 
    ups_name       = ".$anvil->Database->quote($ups_name).", 
    ups_ip_address = ".$anvil->Database->quote($ups_ip_address).", 
    ups_agent      = ".$anvil->Database->quote($ups_agent).", 
    modified_date  = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
WHERE
    ups_uuid       = ".$anvil->Database->quote($ups_uuid)."
;";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query =~ /passw/ ? $anvil->Log->is_secure($query) : $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	else
	{
		# No, INSERT.
		   $ups_uuid = $anvil->Get->uuid();
		my $query      = "
INSERT INTO 
    upses 
(
    ups_uuid, 
    ups_name, 
    ups_ip_address, 
    ups_agent, 
    modified_date
) VALUES (
    ".$anvil->Database->quote($ups_uuid).", 
    ".$anvil->Database->quote($ups_name).",
    ".$anvil->Database->quote($ups_ip_address).",
    ".$anvil->Database->quote($ups_agent).",
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query =~ /passw/ ? $anvil->Log->is_secure($query) : $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, uuid => $uuid, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	
	return($ups_uuid);
}


=head2 insert_or_update_users

This updates (or inserts) a record in the 'users' table. The C<< user_uuid >> referencing the database row will be returned.

If there is an error, C<< !!error!! >> is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 user_uuid (optional)

Is passed, the associated record will be updated.

=head3 user_name (required)

This is the user's name they type when logging into Striker.

=head3 user_password_hash (required)

This is either the B<< hash >> of the user's password, or the raw password. Which it is will be determined by whether C<< user_salt >> is passed in. If it is, C<< user_algorithm >> and C<< user_hash_count >> will also be required. If not, the password will be hashed (and a salt generated) using the default algorithm and hash count.

=head3 user_salt (optional, see 'user_password_hash')

This is the random salt used to generate the password hash.

=head3 user_algorithm (optional, see 'user_password_hash')

This is the algorithm used to create the password hash (with the salt appended to the password).

=head3 user_hash_count (optional, see 'user_password_hash')

This is how many times the initial hash is re-encrypted. 

=head3 user_language (optional, default 'sys::language')

=head3 user_is_admin (optional, default '0')

This determines if the user is an administrator or not. If set to C<< 1 >>, then all features and functions are available to the user.

=head3 user_is_experienced (optional, default '0')

This determines if the user is trusted with potentially dangerous operations, like changing the disk space allocated to a server, deleting a server, and so forth. This also reduces the number of confirmation boxes presented to the user. Set to C<< 1 >> to enable.

=head3 user_is_trusted (optional, default '0')

This determines if the user is trusted to perform operations that are inherently safe, but can cause service interruptions. This includes shutting down (gracefully or forced) servers. Set to C<< 1 >> to enable.

=cut
sub insert_or_update_users
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_states()" }});
	
	my $uuid                = defined $parameter->{uuid}                ? $parameter->{uuid}                : "";
	my $file                = defined $parameter->{file}                ? $parameter->{file}                : "";
	my $line                = defined $parameter->{line}                ? $parameter->{line}                : "";
	my $user_uuid           = defined $parameter->{user_uuid}           ? $parameter->{user_uuid}           : "";
	my $user_name           = defined $parameter->{user_name}           ? $parameter->{user_name}           : "";
	my $user_password_hash  = defined $parameter->{user_password_hash}  ? $parameter->{user_password_hash}  : "";
	my $user_salt           = defined $parameter->{user_salt}           ? $parameter->{user_salt}           : "";
	my $user_algorithm      = defined $parameter->{user_algorithm}      ? $parameter->{user_algorithm}      : "";
	my $user_hash_count     = defined $parameter->{user_hash_count}     ? $parameter->{user_hash_count}     : "";
	my $user_language       = defined $parameter->{user_language}       ? $parameter->{user_language}       : $anvil->data->{sys}{language};
	my $user_is_admin       = defined $parameter->{user_is_admin}       ? $parameter->{user_is_admin}       : 0;
	my $user_is_experienced = defined $parameter->{user_is_experienced} ? $parameter->{user_is_experienced} : 0;
	my $user_is_trusted     = defined $parameter->{user_is_trusted}     ? $parameter->{user_is_trusted}     : 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                => $uuid, 
		file                => $file, 
		line                => $line, 
		user_uuid           => $user_uuid, 
		user_name           => $user_name, 
		user_password_hash  => $user_salt ? $user_password_hash : $anvil->Log->is_secure($user_password_hash), 
		user_salt           => $user_salt, 
		user_algorithm      => $user_algorithm, 
		user_hash_count     => $user_hash_count, 
		user_language       => $user_language, 
		user_is_admin       => $user_is_admin, 
		user_is_experienced => $user_is_experienced, 
		user_is_trusted     => $user_is_trusted, 
	}});
	
	if (not $user_name)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_users()", parameter => "user_name" }});
		return("");
	}
	if (not $user_password_hash)
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_users()", parameter => "user_password_hash" }});
		return("");
	}
	
	# If we have a salt, we need the algorithm and hash count. If not, we'll generate the hash by 
	# treating the password like the initial string.
	if ($user_salt)
	{
		# We have a salt, so we also need the algorithm and loop count.
		if (not $user_algorithm)
		{
			# Throw an error and exit.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_users()", parameter => "user_algorithm" }});
			return("");
		}
		if (not $user_hash_count)
		{
			# Throw an error and exit.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_users()", parameter => "user_hash_count" }});
			return("");
		}
	}
	else
	{
		# No salt given, we'll generate a hash now.
		my $answer             = $anvil->Account->encrypt_password({password => $user_password_hash});
		   $user_password_hash = $answer->{user_password_hash};
		   $user_salt          = $answer->{user_salt};
		   $user_algorithm     = $answer->{user_algorithm};
		   $user_hash_count    = $answer->{user_hash_count};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			user_password_hash => $user_salt ? $user_password_hash : $anvil->Log->is_secure($user_password_hash) , 
			user_salt          => $user_salt, 
			user_algorithm     => $user_algorithm, 
			user_hash_count    => $user_hash_count, 
		}});
		
		if (not $user_salt)
		{
			# Something went wrong.
			return("");
		}
	}
	
	# If we don't have a UUID, see if we can find one for the given user server name.
	if (not $user_uuid)
	{
		my $query = "
SELECT 
    user_uuid 
FROM 
    users 
WHERE 
    user_name = ".$anvil->Database->quote($user_name)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		foreach my $row (@{$results})
		{
			$user_uuid = $row->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { user_uuid => $user_uuid }});
		}
	}
	
	# If I still don't have an user_uuid, we're INSERT'ing .
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { user_uuid => $user_uuid }});
	if (not $user_uuid)
	{
		# It's possible that this is called before the host is recorded in the database. So to be
		# safe, we'll return without doing anything if there is no host_uuid in the database.
		my $hosts = $anvil->Database->get_hosts();
		my $found = 0;
		foreach my $hash_ref (@{$hosts})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"hash_ref->{host_uuid}" => $hash_ref->{host_uuid}, 
				"sys::host_uuid"        => $anvil->data->{sys}{host_uuid}, 
			}});
			if ($hash_ref->{host_uuid} eq $anvil->data->{sys}{host_uuid})
			{
				$found = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { found => $found }});
			}
		}
		if (not $found)
		{
			# We're out.
			return("");
		}
		
		# INSERT
		   $user_uuid = $anvil->Get->uuid();
		my $query     = "
INSERT INTO 
    users 
(
    user_uuid, 
    user_name,
    user_password_hash, 
    user_salt, 
    user_algorithm, 
    user_hash_count, 
    user_language, 
    user_is_admin, 
    user_is_experienced, 
    user_is_trusted, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($user_uuid).", 
    ".$anvil->Database->quote($user_name).", 
    ".$anvil->Database->quote($user_password_hash).", 
    ".$anvil->Database->quote($user_salt).", 
    ".$anvil->Database->quote($user_algorithm).", 
    ".$anvil->Database->quote($user_hash_count).", 
    ".$anvil->Database->quote($user_language).", 
    ".$anvil->Database->quote($user_is_admin).", 
    ".$anvil->Database->quote($user_is_experienced).", 
    ".$anvil->Database->quote($user_is_trusted).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query the rest of the values and see if anything changed.
		my $query = "
SELECT 
    user_name,
    user_password_hash, 
    user_salt, 
    user_algorithm, 
    user_hash_count, 
    user_language, 
    user_is_admin, 
    user_is_experienced, 
    user_is_trusted 
FROM 
    users 
WHERE 
    user_uuid = ".$anvil->Database->quote($user_uuid)." 
;";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count, 
		}});
		if (not $count)
		{
			# I have a user_uuid but no matching record. Probably an error.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "user_uuid", uuid => $user_uuid }});
			return("");
		}
		foreach my $row (@{$results})
		{
			my $old_user_name           = $row->[0];
			my $old_user_password_hash  = $row->[1];
			my $old_user_salt           = $row->[2];
			my $old_user_algorithm      = $row->[3];
			my $old_user_hash_count     = $row->[4];
			my $old_user_language       = $row->[5];
			my $old_user_is_admin       = $row->[6];
			my $old_user_is_experienced = $row->[7];
			my $old_user_is_trusted     = $row->[8];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				old_user_name           => $old_user_name, 
				old_user_password_hash  => $old_user_password_hash,
				old_user_salt           => $old_user_salt,
				old_user_algorithm      => $old_user_algorithm,
				old_user_hash_count     => $old_user_hash_count,
				old_user_language       => $old_user_language,
				old_user_is_admin       => $old_user_is_admin,
				old_user_is_experienced => $old_user_is_experienced,
				old_user_is_trusted     => $old_user_is_trusted,
			}});
			
			# Anything change?
			if (($old_user_name           ne $user_name)           or 
			    ($old_user_name           ne $user_name)           or 
			    ($old_user_password_hash  ne $user_password_hash)  or 
			    ($old_user_salt           ne $user_salt)           or 
			    ($old_user_algorithm      ne $user_algorithm)      or 
			    ($old_user_hash_count     ne $user_hash_count)     or 
			    ($old_user_language       ne $user_language)       or 
			    ($old_user_is_admin       ne $user_is_admin)       or 
			    ($old_user_is_experienced ne $user_is_experienced) or 
			    ($old_user_is_trusted     ne $user_is_trusted))
			{
				# Something changed, save.
				my $query = "
UPDATE 
    users 
SET 
    user_name           = ".$anvil->Database->quote($user_name).", 
    user_password_hash  = ".$anvil->Database->quote($user_password_hash).",  
    user_salt           = ".$anvil->Database->quote($user_salt).",  
    user_algorithm      = ".$anvil->Database->quote($user_algorithm).",  
    user_hash_count     = ".$anvil->Database->quote($user_hash_count).",  
    user_language       = ".$anvil->Database->quote($user_language).",  
    user_is_admin       = ".$anvil->Database->quote($user_is_admin).", 
    user_is_experienced = ".$anvil->Database->quote($user_is_experienced).", 
    user_is_trusted     = ".$anvil->Database->quote($user_is_trusted).", 
    modified_date       = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    user_uuid           = ".$anvil->Database->quote($user_uuid)." 
";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			}
		}
	}
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { user_uuid => $user_uuid }});
	return($user_uuid);
}


=head2 insert_or_update_variables

This updates (or inserts) a record in the 'variables' table. The C<< state_uuid >> referencing the database row will be returned.

Unlike the other methods of this type, this method can be told to update the 'variable_value' only. This is so because the section, description and default columns rarely ever change. If this is set and the variable name is new, an INSERT will be done the same as if it weren't set, with the unset columns set to an empty string.

If there is an error, C<< !!error!! >> is returned.

Parameters;

=head3 uuid (optional)

If set, only the corresponding database will be written to.

=head3 file (optional)

If set, this is the file name logged as the source of any INSERTs or UPDATEs.

=head3 line (optional)

If set, this is the file line number logged as the source of any INSERTs or UPDATEs.

=head3 variable_uuid (optional)

If this is passed, the variable will be updated using this UUID, which allows the C<< variable_name >> to be changed.

=head3 variable_name (optional)

This is the name of variable to be inserted or updated. 

B<NOTE>: This paramter is only optional if C<< variable_uuid >> is used. Otherwise this parameter is required.

=head3 variable_value (optional)

This is the value to set the variable to. If it is empty, the variable's value will be set to empty.

=head3 variable_default (optional)

If this is set, it changes the default value for the given variable. This is used to tell the user what the default was or enable resetting to defaults.

=head3 variable_description (optional)

This can be set to a string key that explains what this variable does when presenting this variable to a user.

=head3 variable_section (option)

If this is set, it will group this variable with other variables in the same section when displaying this variable to the user.

=head3 variable_source_uuid (optional)

This is an optional field to mark a source UUID that this variable belongs to. By default, a variable applies to everything that reads it, but if this is set, the variable can be restricted to just a given record. This is often used to tag the variable to a particular host by setting the host UUID, but it could also be a UUID of an entry in another database table, when C<< variable_source_table >> is used. Ultimately, this can be used however you want.

=head3 variable_source_table (optional)

This is an optional database table name that the variables relates to. Generally it is used along side C<< variable_source_uuid >>, but that isn't required.

=head3 update_value_only (optional, default '0')

When set to C<< 1 >>, this method will only update the variable's C<< variable_value >> column. Any other parameters are used to help locate the variable to update only. If the C<< variable_uuid >> isn't passed and can't be found, the call will fail and an empty string is returned.

=cut
sub insert_or_update_variables
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_variables()" }});
	
	my $uuid                  = defined $parameter->{uuid}                  ? $parameter->{uuid}                  : "";
	my $file                  = defined $parameter->{file}                  ? $parameter->{file}                  : "";
	my $line                  = defined $parameter->{line}                  ? $parameter->{line}                  : "";
	my $variable_uuid         = defined $parameter->{variable_uuid}         ? $parameter->{variable_uuid}         : "";
	my $variable_name         = defined $parameter->{variable_name}         ? $parameter->{variable_name}         : "";
	my $variable_value        = defined $parameter->{variable_value}        ? $parameter->{variable_value}        : "";
	my $variable_default      = defined $parameter->{variable_default}      ? $parameter->{variable_default}      : "";
	my $variable_description  = defined $parameter->{variable_description}  ? $parameter->{variable_description}  : "";
	my $variable_section      = defined $parameter->{variable_section}      ? $parameter->{variable_section}      : "";
	my $variable_source_uuid  = defined $parameter->{variable_source_uuid}  ? $parameter->{variable_source_uuid}  : "";
	my $variable_source_table = defined $parameter->{variable_source_table} ? $parameter->{variable_source_table} : "";
	my $update_value_only     = defined $parameter->{update_value_only}     ? $parameter->{update_value_only}     : 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                  => $uuid, 
		file                  => $file, 
		line                  => $line, 
		variable_uuid         => $variable_uuid, 
		variable_name         => $variable_name, 
		variable_value        => $variable_value, 
		variable_default      => $variable_default, 
		variable_description  => $variable_description, 
		variable_section      => $variable_section, 
		variable_source_uuid  => $variable_source_uuid, 
		variable_source_table => $variable_source_table, 
		update_value_only     => $update_value_only, 
	}});
	
	# We'll need either the name or UUID.
	if ((not $variable_name) && (not $variable_uuid))
	{
		# Neither given, throw an error and return.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0037"});
		return("!!error!!");
	}
	
	# If we have a variable UUID but not a name, read the variable name. If we don't have a UUID, see if
	# we can find one for the given variable name.
	if (($anvil->Validate->is_uuid({uuid => $variable_uuid})) && (not $variable_name))
	{
		my $query = "
SELECT 
    variable_name 
FROM 
    variables 
WHERE 
    variable_uuid = ".$anvil->Database->quote($variable_uuid);
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		$variable_name = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__})->[0]->[0];
		$variable_name = "" if not defined $variable_name;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { variable_name => $variable_name }});
	}
	
	if (($variable_name) && (not $variable_uuid))
	{
		my $query = "
SELECT 
    variable_uuid 
FROM 
    variables 
WHERE 
    variable_name = ".$anvil->Database->quote($variable_name);
		if (($variable_source_uuid ne "") && ($variable_source_table ne ""))
		{
			$query .= "
AND 
    variable_source_uuid  = ".$anvil->Database->quote($variable_source_uuid)." 
AND 
    variable_source_table = ".$anvil->Database->quote($variable_source_table)." 
";
		}
		$query .= ";";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count,
		}});
		foreach my $row (@{$results})
		{
			$variable_uuid = $row->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { variable_uuid => $variable_uuid }});
		}
	}
	
	# If I still don't have an variable_uuid, we're INSERT'ing (unless we've been told to update the 
	# value only, in which case we do nothing).
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { variable_uuid => $variable_uuid }});
	if (not $variable_uuid)
	{
		# Were we asked to updat only?
		if ($update_value_only)
		{
			# Nothing to do.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, priority => "alert", key => "warning_0030"});
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 1, list => { 
				uuid                  => $uuid, 
				file                  => $file, 
				line                  => $line, 
				variable_uuid         => $variable_uuid, 
				variable_name         => $variable_name, 
				variable_value        => $variable_value, 
				variable_default      => $variable_default, 
				variable_description  => $variable_description, 
				variable_section      => $variable_section, 
				variable_source_uuid  => $variable_source_uuid, 
				variable_source_table => $variable_source_table, 
				update_value_only     => $update_value_only, 
			}});
			return("");
		}
		
		# INSERT
		   $variable_uuid = $anvil->Get->uuid();
		my $query         = "
INSERT INTO 
    variables 
(
    variable_uuid, 
    variable_name, 
    variable_value, 
    variable_default, 
    variable_description, 
    variable_section, 
    variable_source_uuid, 
    variable_source_table, 
    modified_date 
) VALUES (
    ".$anvil->Database->quote($variable_uuid).", 
    ".$anvil->Database->quote($variable_name).", 
    ".$anvil->Database->quote($variable_value).", 
    ".$anvil->Database->quote($variable_default).", 
    ".$anvil->Database->quote($variable_description).", 
    ".$anvil->Database->quote($variable_section).", 
    ".$anvil->Database->quote($variable_source_uuid).", 
    ".$anvil->Database->quote($variable_source_table).", 
    ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})."
);
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
	}
	else
	{
		# Query only the value
		if ($update_value_only)
		{
			my $query = "
SELECT 
    variable_value 
FROM 
    variables 
WHERE 
    variable_uuid = ".$anvil->Database->quote($variable_uuid);
			if (($variable_source_uuid ne "") && ($variable_source_table ne ""))
			{
				$query .= "
AND 
    variable_source_table = ".$anvil->Database->quote($variable_source_table)." 
AND 
    variable_source_uuid  = ".$anvil->Database->quote($variable_source_uuid)." 
";
			}
			$query .= ";";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count,
			}});
			if (not $count)
			{
				# I have a variable_uuid, source table and source uuid but no matching record. Probably an error.
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0217", variables => { 
					variable_uuid         => $variable_uuid, 
					variable_source_table => $variable_source_table, 
					variable_source_uuid  => $variable_source_uuid, 
				}});
				return("");
			}
			foreach my $row (@{$results})
			{
				my $old_variable_value = $row->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { old_variable_value => $old_variable_value }});
				
				# Anything change?
				if ($old_variable_value ne $variable_value)
				{
					# Variable changed, save.
					my $query = "
UPDATE 
    variables 
SET 
    variable_value = ".$anvil->Database->quote($variable_value).", 
    modified_date  = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    variable_uuid  = ".$anvil->Database->quote($variable_uuid);
					if (($variable_source_uuid ne "") && ($variable_source_table ne ""))
					{
						$query .= "
AND 
    variable_source_uuid  = ".$anvil->Database->quote($variable_source_uuid)." 
AND 
    variable_source_table = ".$anvil->Database->quote($variable_source_table)." 
";
					}
					$query .= ";";
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
					
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
			}
		}
		else
		{
			# Query the rest of the values and see if anything changed.
			my $query = "
SELECT 
    variable_name, 
    variable_value, 
    variable_default, 
    variable_description, 
    variable_section 
FROM 
    variables 
WHERE 
    variable_uuid = ".$anvil->Database->quote($variable_uuid)." 
;";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count,
			}});
			if (not $count)
			{
				# I have a variable_uuid but no matching record. Probably an error.
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "variable_uuid", uuid => $variable_uuid }});
				return("");
			}
			foreach my $row (@{$results})
			{
				my $old_variable_name        = $row->[0];
				my $old_variable_value       = $row->[1];
				my $old_variable_default     = $row->[2];
				my $old_variable_description = $row->[3];
				my $old_variable_section     = $row->[4];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					old_variable_name        => $old_variable_name, 
					old_variable_value       => $old_variable_value, 
					old_variable_default     => $old_variable_default, 
					old_variable_description => $old_variable_description, 
					old_variable_section     => $old_variable_section, 
				}});
				
				# Anything change?
				if (($old_variable_name        ne $variable_name)        or 
				    ($old_variable_value       ne $variable_value)       or 
				    ($old_variable_default     ne $variable_default)     or 
				    ($old_variable_description ne $variable_description) or 
				    ($old_variable_section     ne $variable_section))
				{
					# Something changed, save.
					my $query = "
UPDATE 
    variables 
SET 
    variable_name        = ".$anvil->Database->quote($variable_name).", 
    variable_value       = ".$anvil->Database->quote($variable_value).", 
    variable_default     = ".$anvil->Database->quote($variable_default).", 
    variable_description = ".$anvil->Database->quote($variable_description).", 
    variable_section     = ".$anvil->Database->quote($variable_section).", 
    modified_date        = ".$anvil->Database->quote($anvil->data->{sys}{database}{timestamp})." 
WHERE 
    variable_uuid        = ".$anvil->Database->quote($variable_uuid)." 
";
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
					
					$anvil->Database->write({uuid => $uuid, query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
				}
			}
		}
	}
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { variable_uuid => $variable_uuid }});
	return($variable_uuid);
}


=head2 lock_file

This reads, sets or updates the database lock file timestamp.

Parameters;

=head3 do (required, default 'get')

This controls whether we're setting (C<< set >>) or checking for (C<< get >>) a lock file on the local system. 

If setting, or if checking and a lock file is found, the timestamp (in unixtime) in the lock fike is returned. If a lock file isn't found, C<< 0 >> is returned.

=cut
sub lock_file
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->lock_file()" }});
	
	my $do = $parameter->{'do'} ? $parameter->{'do'} : "get";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 'do' => $do }});
	
	my $lock_time = 0;
	if ($do eq "set")
	{
		$lock_time = time;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { lock_time => $lock_time }});
		$anvil->Storage->write_file({
			file      => $anvil->data->{path}{'lock'}{database}, 
			body      => $lock_time,
			overwrite => 1,
		});
	}
	else
	{
		# Read the lock file's time stamp, if the file exists.
		if (-e $anvil->data->{path}{'lock'}{database})
		{
			$lock_time = $anvil->Storage->read_file({file => $anvil->data->{path}{'lock'}{database}});
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { lock_time => $lock_time }});
		}
	}
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { lock_time => $lock_time }});
	return($lock_time);
}


=head2 locking

This handles requesting, releasing and waiting on locks.

If it is called without any parameters, it will act as a pauser that halts the program until any existing locks are released.

Parameters;

=head3 request (optional)

When set to C<< 1 >>, a log request will be made. If an existing lock exists, it will wait until the existing lock clears before requesting the lock and returning.

=head3 release (optional)

When set to C<< 1 >>, an existing lock held by this machine will be release.

=head3 renew (optional)

When set to C<< 1 >>, an existing lock held by this machine will be renewed.

=head3 check (optional)

This checks to see if a lock is in place and, if it is, the lock string is returned (in the format C<< <host_name>::<source_uuid>::<unix_time_stamp> >> that requested the active lock.

=cut
sub locking
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->locking()" }});
	
	my $request     = defined $parameter->{request}     ? $parameter->{request}     : 0;
	my $release     = defined $parameter->{release}     ? $parameter->{release}     : 0;
	my $renew       = defined $parameter->{renew}       ? $parameter->{renew}       : 0;
	my $check       = defined $parameter->{check}       ? $parameter->{check}       : 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		request => $request, 
		release => $release, 
		renew   => $renew, 
		check   => $check, 
	}});
	
	# These are used to ID this lock.
	my $source_name = $anvil->_host_name;
	my $source_uuid = $anvil->data->{sys}{host_uuid};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		source_name => $source_name, 
		source_uuid => $source_uuid, 
	}});
	
	my $set            = 0;
	my $variable_name  = "lock_request";
	my $variable_value = $source_name."::".$source_uuid."::".time;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		variable_name  => $variable_name, 
		variable_value => $variable_value, 
	}});
	
	# Make sure we have a sane lock age
	if ((not defined $anvil->data->{sys}{database}{locking}{reap_age}) or 
	    (not $anvil->data->{sys}{database}{locking}{reap_age})         or 
	    ($anvil->data->{sys}{database}{locking}{reap_age} =~ /\D/)
	)
	{
		$anvil->data->{sys}{database}{locking}{reap_age} = $anvil->data->{defaults}{database}{locking}{reap_age};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::locking::reap_age" => $anvil->data->{sys}{database}{locking}{reap_age} }});
	}
	
	# If I have been asked to check, we will return the variable_uuid if a lock is set.
	if ($check)
	{
		my ($lock_value, $variable_uuid, $modified_date) = $anvil->Database->read_variable({variable_name => $variable_name});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			lock_value    => $lock_value, 
			variable_uuid => $variable_uuid, 
			modified_date => $modified_date, 
		}});
		
		return($lock_value);
	}
	
	# If I've been asked to clear a lock, do so now.
	if ($release)
	{
		# We check to see if there is a lock before we clear it. This way we don't log that we 
		# released a lock unless we really released a lock.
		my ($lock_value, $variable_uuid, $modified_date) = $anvil->Database->read_variable({variable_name => $variable_name});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			lock_value    => $lock_value, 
			variable_uuid => $variable_uuid, 
			modified_date => $modified_date, 
		}});
		
		if ($lock_value)
		{
			my $variable_uuid = $anvil->Database->insert_or_update_variables({
				variable_name     => $variable_name,
				variable_value    => "",
				update_value_only => 1,
			});
			$anvil->data->{sys}{database}{local_lock_active} = 0;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				variable_uuid            => $variable_uuid, 
				"sys::local_lock_active" => $anvil->data->{sys}{database}{local_lock_active}, 
			}});
			
			# Log that the lock has been released.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0039", variables => { host => $anvil->_host_name }});
		}
		
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { set => $set }});
		return($set);
	}
	
	# If I've been asked to renew, do so now.
	if ($renew)
	{
		# Yup, do it.
		my $variable_uuid = $anvil->Database->insert_or_update_variables({
			variable_name     => $variable_name,
			variable_value    => $variable_value,
			update_value_only => 1,
		});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { variable_uuid => $variable_uuid }});
		
		if ($variable_uuid)
		{
			$set = 1;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { set => $set }});
		}
		$anvil->data->{sys}{database}{local_lock_active} = time;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			variable_uuid            => $variable_uuid, 
			"sys::local_lock_active" => $anvil->data->{sys}{database}{local_lock_active}, 
		}});
		
		# Log that we've renewed the lock.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0044", variables => { host => $anvil->_host_name }});
		
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { set => $set }});
		return($set);
	}
	
	# We always check for, and then wait for, locks. Read in the locks, if any. If any are set and they are 
	# younger than sys::database::locking::reap_age, we'll hold.
	my $waiting = 1;
	while ($waiting)
	{
		# Set the 'waiting' to '0'. If we find a lock, we'll set it back to '1'.
		$waiting = 0;
		
		# See if we had a lock.
		my ($lock_value, $variable_uuid, $modified_date) = $anvil->Database->read_variable({variable_name => $variable_name});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			waiting       => $waiting, 
			lock_value    => $lock_value, 
			variable_uuid => $variable_uuid, 
			modified_date => $modified_date, 
		}});
		if ($lock_value =~ /^(.*?)::(.*?)::(\d+)/)
		{
			my $lock_source_name = $1;
			my $lock_source_uuid = $2;
			my $lock_time        = $3;
			my $current_time     = time;
			my $timeout_time     = $lock_time + $anvil->data->{sys}{database}{locking}{reap_age};
			my $lock_age         = $current_time - $lock_time;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				lock_source_name => $lock_source_name, 
				lock_source_uuid => $lock_source_uuid, 
				current_time     => $current_time, 
				lock_time        => $lock_time, 
				timeout_time     => $timeout_time, 
				lock_age         => $lock_age, 
			}});
			
			# If the lock is stale, delete it.
			if ($current_time > $timeout_time)
			{
				# The lock is stale.
				my $variable_uuid = $anvil->Database->insert_or_update_variables({
					variable_name     => $variable_name,
					variable_value    => "",
					update_value_only => 1,
				});
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { variable_uuid => $variable_uuid }});
			}
			# Only wait if this isn't our own lock.
			elsif ($lock_source_uuid ne $source_uuid)
			{
				# Mark 'wait', set inactive and sleep.
				$anvil->Database->mark_active({set => 0});
				
				$waiting = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					lock_source_uuid => $lock_source_uuid, 
					source_uuid      => $source_uuid, 
					waiting          => $waiting, 
				}});
				sleep 5;
			}
		}
	}
	
	# If I am here, there are no pending locks. Have I been asked to set one?
	if ($request)
	{
		# Yup, do it.
		my $variable_uuid = $anvil->Database->insert_or_update_variables({
			variable_name     => $variable_name,
			variable_value    => $variable_value,
			update_value_only => 1,
		});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { variable_uuid => $variable_uuid }});
		
		if ($variable_uuid)
		{
			$set = 1;
			$anvil->data->{sys}{database}{local_lock_active} = time;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				set                      => $set, 
				variable_uuid            => $variable_uuid, 
				"sys::local_lock_active" => $anvil->data->{sys}{database}{local_lock_active}, 
			}});
			
			# Log that we've got the lock.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0045", variables => { host => $anvil->_host_name }});
		}
	}
	
	# Now return.
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { set => $set }});
	return($set);
}


=head2 manage_anvil_conf

This adds, removes or updates a database entry in a machine's anvil.conf file. This returns C<< 0 >> on success, C<< 1 >> if there was a problem.

Parameters;

=head3 db_host (required)

This is the IP address or host name of the database server.

=head3 db_host_uuid (required)

This is the C<< host_uuid >> of the server hosting the database we will be managing.

=head3 db_password (required)

This is the password used to log into the database. 

=head3 db_ping (optional, default '1')

This sets whether the target will ping the DB server before trying to connect. See C<< Database->connect >> for more information.

=head3 db_port (optional, default '5432')

This is the port used to connect to the database server.

=head3 password (optional)

If C<< target >> is set, this is the password used to log into the remote system as the C<< remote_user >>. If it is not set, an attempt to connect without a password will be made (though this will usually fail).

B<< NOTE >>: Do not confuse this with C<< db_password >>. This is the password to log into the remote machine being managed.

=head3 port (optional, default 22)

If C<< target >> is set, this is the TCP port number used to connect to the remote machine.

B<< NOTE >>: Do not confuse this with C<< db_port >>. This is the port used to SSH into a remote machine.

=head3 remote_user (optional)

If C<< target >> is set, this is the user account that will be used when connecting to the remote system.

B<< NOTE >>: Do not confuse this with C<< db_user >>. This is the user to use when logging into the machine being managed.

=head3 remove (optional, default '0')

If set to C<< 1 >>, any existing extries for C<< host_uuid >> will be removed from that machine being managed.

B<< NOTE >>: When this is set to C<< 1 >>, C<< db_password >> and C<< db_host >> are not required.

=head3 target (optional)

If set, the file will be read from the target machine. This must be either an IP address or a resolvable host name. 

The file will be copied to the local system using C<< $anvil->Storage->rsync() >> and stored in C<< /tmp/<file_path_and_name>.<target> >>. if C<< cache >> is set, the file will be preserved locally. Otherwise it will be deleted once it has been read into memory.

B<< Note >>: the temporary file will be prefixed with the path to the file name, with the C<< / >> converted to C<< _ >>.

=cut
sub manage_anvil_conf
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->manage_anvil_conf()" }});
	
	my $db_password  = defined $parameter->{db_password}  ? $parameter->{db_password}  : "";
	my $db_ping      = defined $parameter->{db_ping}      ? $parameter->{db_ping}      : 1;
	my $db_port      = defined $parameter->{db_port}      ? $parameter->{db_port}      : 5432;
	my $db_host      = defined $parameter->{db_host}      ? $parameter->{db_host}      : "";
	my $db_host_uuid = defined $parameter->{db_host_uuid} ? $parameter->{db_host_uuid} : "";
	my $password     = defined $parameter->{password}     ? $parameter->{password}     : "";
	my $port         = defined $parameter->{port}         ? $parameter->{port}         : 22;
	my $remote_user  = defined $parameter->{remote_user}  ? $parameter->{remote_user}  : "root";
	my $remove       = defined $parameter->{remove}       ? $parameter->{remove}       : 0;
	my $target       = defined $parameter->{target}       ? $parameter->{target}       : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		db_password  => $anvil->Log->is_secure($db_password), 
		db_ping      => $db_ping, 
		db_port      => $db_port, 
		db_host_uuid => $db_host_uuid, 
		password     => $anvil->Log->is_secure($password), 
		port         => $port, 
		remote_user  => $remote_user, 
		remove       => $remove,
		target       => $target,
	}});
	
	if (not $db_host_uuid)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->manage_anvil_conf()", parameter => "db_host_uuid" }});
		return(1);
	}
	elsif (not $anvil->Validate->is_uuid({uuid => $db_host_uuid}))
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "error_0031", variables => { db_host_uuid => $db_host_uuid }});
		return(1);
	}
	if (not $remove)
	{
		if (not $db_host)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->manage_anvil_conf()", parameter => "db_host" }});
			return(0);
		}
		if (not $db_password)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->manage_anvil_conf()", parameter => "db_password" }});
			return(0);
		}
	}
	
	# Read in the anvil.conf
	my ($anvil_conf) = $anvil->Storage->read_file({
		debug       => $debug, 
		file        => $anvil->data->{path}{configs}{'anvil.conf'},
		force_read  => 1, 
		port        => $port, 
		password    => $anvil->Log->is_secure($password), 
		remote_user => $remote_user, 
		secure      => 1, 
		target      => $target,
	});
	
	if ($anvil_conf eq "!!error!!")
	{
		# Something went wrong.
		return(1);
	}
	
	# Now walk through the file and look for '### end db list ###'
	my $rewrite            = 0;
	my $host_variable      = "database::${db_host_uuid}::host";
	my $host_different     = 1;
	my $port_variable      = "database::${db_host_uuid}::port";
	my $port_different     = 1;
	my $password_variable  = "database::${db_host_uuid}::password";
	my $password_different = 1;
	my $ping_variable      = "database::${db_host_uuid}::ping";
	my $ping_different     = 1;
	my $delete_reported    = 0;
	my $update_reported    = 0;
	my $new_body           = "";
	my $just_deleted       = 0;
	my $test_line          = "database::${db_host_uuid}::";
	my $insert             = "";
	my $host_seen          = 0;
	
	# If we're not removing, and we don't find the entry at all, this will be inserted.
	if (not $remove)
	{
		$insert =  $host_variable."		=	".$db_host."\n";
		$insert .= $port_variable."		=	".$db_port."\n";
		$insert .= $password_variable."	=	".$db_password."\n";
		$insert .= $ping_variable."		=	".$db_ping."\n";
	}
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		host_variable     => $host_variable, 
		port_variable     => $port_variable, 
		password_variable => $anvil->Log->is_secure($password_variable), 
		ping_variable     => $ping_variable,
		insert            => $anvil->Log->is_secure($insert), 
		test_line         => $test_line, 
	}});
	
	foreach my $line (split/\n/, $anvil_conf)
	{
		# Secure password lines ? 
		my $secure = (($line =~ /password/) && ($line !~ /^#/)) ? 1 : 0;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, secure => $secure, level => $debug, list => { line => $line }});

		# If I removed an entry, I also want to delete the white space after it.
		if (($just_deleted) && ((not $line) or ($line =~ /^\s+$/)))
		{
			$just_deleted = 0;
			next;
		}
		$just_deleted = 0;
		
		# If we've hit the end of the DB list, see if we need to insert a new entry.
		if ($line eq "### end db list ###")
		{
			# If I've not seen this DB, enter it.
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, secure => 0, level => 2, list => { 
				host_seen => $host_seen,
				remove    => $remove,
			}});
			if ((not $host_seen) && (not $remove))
			{
				$new_body .= $insert."\n";
				$rewrite  =  1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, secure => 1, level => 2, list => { 
					new_body => $new_body,
					rewrite  => $rewrite,
				}});
			}
		}
		
		# Now Skip any more comments.
		if ($line =~ /^#/)
		{
			$new_body .= $line."\n";
			next;
		}
		# Process lines with the 'var = val' format
		if ($line =~ /^(.*?)(\s*)=(\s*)(.*)$/)
		{
			my $variable    = $1;
			my $left_space  = $2;
			my $right_space = $3; 
			my $value       = $4;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
				"s1:variable"    => $variable,
				"s2:value"       => $value, 
				"s3:left_space"  => $left_space, 
				"s4:right_space" => $right_space, 
			}});
			
			# Is the the host line we're possibly updating?
			if ($variable eq $host_variable)
			{
				# Yup. Are we removing it, or do we need to edit it?
				$host_seen = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
					"s1:value"     => $value,
					"s2:db_host"   => $db_host, 
					"s3:host_seen" => $host_seen, 
				}});
				if ($remove)
				{
					# Remove the line
					$delete_reported = 1;
					$just_deleted    = 1;
					$rewrite         = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
						just_deleted    => $just_deleted, 
						rewrite         => $rewrite,
						delete_reported => $delete_reported, 
					}});
					next;
				}
				elsif ($value eq $db_host)
				{
					# No change.
					$host_different = 0;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { host_different => $host_different }});
				}
				else
				{
					# Needs to be updated.
					$line    = $variable.$left_space."=".$right_space.$db_host;
					$rewrite = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
						line    => $line,
						rewrite => $rewrite, 
					}});
				}
			}
			elsif ($variable eq $port_variable)
			{
				# Port line
				$host_seen = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
					"s1:value"     => $value,
					"s2:port"      => $port, 
					"s3:host_seen" => $host_seen, 
				}});
				if ($remove)
				{
					# Remove it
					$delete_reported = 1;
					$just_deleted    = 1;
					$rewrite         = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
						delete_reported => $delete_reported, 
						just_deleted    => $just_deleted, 
						rewrite         => $rewrite,
					}});
					next;
				}
				elsif ($value eq $port)
				{
					# No change.
					$port_different = 0;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { port_different => $port_different }});
				}
				else
				{
					# Needs to be updated.
					$update_reported = 1;
					$line            = $variable.$left_space."=".$right_space.$port;
					$rewrite         = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
						update_reported => $update_reported, 
						line            => $line,
						rewrite         => $rewrite, 
					}});
				}
			}
			elsif ($variable eq $password_variable)
			{
				# Password
				$host_seen = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, secure => 0, list => { 
					"s1:value"     => $value,
					"s2:password"  => $anvil->Log->is_secure($password), 
					"s3:host_seen" => $host_seen, 
				}});
				if ($remove)
				{
					# Remove it
					$delete_reported = 1;
					$just_deleted    = 1;
					$rewrite         = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
						delete_reported => $delete_reported, 
						just_deleted    => $just_deleted, 
						rewrite         => $rewrite,
					}});
					next;
				}
				elsif ($value eq $password)
				{
					# No change.
					$password_different = 0;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { password_different => $password_different }});
				}
				else
				{
					# Changed, update it
					$update_reported = 1;
					$line            = $variable.$left_space."=".$right_space.$password;
					$rewrite         = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
						update_reported => $update_reported, 
						line            => $anvil->Log->is_secure($line),
						rewrite         => $rewrite, 
					}});
				}
			}
			elsif ($variable eq $ping_variable)
			{
				# Ping?
				$host_seen = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
					"s1:value"     => $value,
					"s2:db_ping"   => $db_ping, 
					"s3:host_seen" => $host_seen, 
				}});
				if ($remove)
				{
					# Remove it
					$delete_reported = 1;
					$just_deleted    = 1;
					$rewrite         = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
						delete_reported => $delete_reported, 
						just_deleted    => $just_deleted, 
						rewrite         => $rewrite,
					}});
					next;
				}
				elsif ($value eq $db_ping)
				{
					# No change.
					$ping_different = 0;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { ping_different => $ping_different }});
				}
				else
				{
					# Changed, update
					$update_reported = 1;
					$line            = $variable.$left_space."=".$right_space.$db_ping;
					$rewrite         = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
						update_reported => $update_reported, 
						line            => $line,
						rewrite         => $rewrite, 
					}});
				}
			}
		}
		# Add the (modified?) line to the new body.
		$new_body .= $line."\n";
	}

	# If there was a change, write the file out.
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
		's1:new_body' => $new_body, 
		's2:rewrite'  => $rewrite,
	}});
	
	if ($rewrite)
	{
		# Backup the original
		my $backup_file = $anvil->Storage->backup({
			debug       => 2,
			secure      => 1, 
			file        => $anvil->data->{path}{configs}{'anvil.conf'},
			password    => $password, 
			port        => $port, 
			remote_user => $remote_user, 
			target      => $target,
		});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { backup_file => $backup_file }});
		
		# Now update!
		my ($failed) = $anvil->Storage->write_file({
			secure      => 1, 
			file        => $anvil->data->{path}{configs}{'anvil.conf'}, 
			body        => $new_body, 
			user        => "admin", 
			group       => "admin", 
			mode        => "0644",
			overwrite   => 1,
			password    => $anvil->Log->is_secure($password), 
			port        => $port, 
			remote_user => $remote_user, 
			target      => $target,
		});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { failed => $failed }});
		if ($failed)
		{
			# Simething went weong.
			return(1);
		}
		
		# If this is a local update, disconnect (if no connections exist, will still clear out known 
		# databases), the re-read the new config.
		if ($anvil->Network->is_local({host => $target}))
		{
			$anvil->Database->disconnect;
			
			# Re-read the config.
			sleep 1;
			$anvil->Storage->read_config({file => $anvil->data->{path}{configs}{'anvil.conf'}});
			
			# Reconnect
			$anvil->Database->connect();
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, secure => 0, key => "log_0132"});
		}
	}
	
	return(0);
}


=head2 mark_active

This sets or clears that the caller is about to work on the database

Parameters;

=head3 set (optional, default C<< 1 >>)

If set to c<< 0 >>, 

=cut
sub mark_active
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->mark_active()" }});
	
	my $set = defined $parameter->{set} ? $parameter->{set} : 1;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { set => $set }});
	
	# If I haven't connected to a database yet, why am I here?
	if (not $anvil->data->{sys}{database}{read_uuid})
	{
		return(0);
	}
	
	my $value = "false";
	if ($set)
	{
		$value = "true";
	}
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { value => $value }});
	
	my $state_uuid = $anvil->Database->insert_or_update_states({
		state_name      => "db_in_use",
		state_host_uuid => $anvil->data->{sys}{host_uuid},
		state_note      => $value,
	});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { state_uuid => $state_uuid }});
	return($state_uuid);
}


=head2 query

This performs a query and returns an array reference of array references (from C<< DBO->fetchall_arrayref >>). The first array contains all the returned rows and each row is an array reference of columns in that row.

If an error occurs, C<< !!error!! >> will be returned.

For example, given the query;

 anvil=# SELECT host_uuid, host_name, host_type FROM hosts ORDER BY host_name ASC;
               host_uuid               |        host_name         | host_type 
 --------------------------------------+--------------------------+-----------
  e27fc9a0-2656-4aaf-80e6-fedb3c339037 | an-a01n01.alteeve.com    | node
  4bea6ddd-c3ff-43e9-8e9e-b2dea1923145 | an-a01n02.alteeve.com    | node
  ff852db7-c77a-403b-877f-91f85f3ad95c | an-striker01.alteeve.com | dashboard
  2dd5aab1-65d6-4416-9bc1-98dc344aa08b | an-striker02.alteeve.com | dashboard
 (4 rows)

The returned array would have four values, one for each returned row. Each row would be an array reference containing three values, one per row. So given the above example;

 my $rows = $anvil->Database->query({query => "SELECT host_uuid, host_name, host_type FROM hosts ORDER BY host_name ASC;"});
 foreach my $columns (@{$results})
 {
 	my $host_uuid = $columns->[0];
 	my $host_name = $columns->[1];
 	my $host_type = $columns->[2];
	print "Host: [$host_name] (UUID: [$host_uuid], type: [$host_type]).\n";
 }

Would print;

 Host: [an-a01n01.alteeve.com] (UUID: [e27fc9a0-2656-4aaf-80e6-fedb3c339037], type: [node]).
 Host: [an-a01n02.alteeve.com] (UUID: [4bea6ddd-c3ff-43e9-8e9e-b2dea1923145], type: [node]).
 Host: [an-striker01.alteeve.com] (UUID: [ff852db7-c77a-403b-877f-91f85f3ad95c], type: [dashboard]).
 Host: [an-striker02.alteeve.com] (UUID: [2dd5aab1-65d6-4416-9bc1-98dc344aa08b], type: [dashboard]).

B<NOTE>: Do not sort the array references; They won't make any sense as the references are randomly created pointers. The arrays will be returned in the order of the returned data, so do your sorting in the query itself.

Parameters;

=head3 uuid (optional)

By default, the local database will be queried (if run on a machine with a database). Otherwise, the first database successfully connected to will be used for queries (as stored in C<< $anvil->data->{sys}{database}{read_uuid} >>).

If you want to read from a specific database, though, you can set this parameter to the ID of the database (C<< database::<id>::host). If you specify a read from a database that isn't available, C<< !!error!! >> will be returned.

=head3 line (optional)

To help with logging the source of a query, C<< line >> can be set to the line number of the script that requested the query. It is generally used along side C<< source >>.

=head3 query (required)

This is the SQL query to perform.

B<NOTE>: ALWAYS use C<< $anvil->Database->quote(...)>> when preparing data coming from ANY external source! Otherwise you'll end up XKCD 327'ing your database eventually...

=head3 secure (optional, defaul '0')

If set, the query will be treated as containing sensitive data and will only be logged if C<< $anvil->Log->secure >> is enabled.

=head3 source (optional)

To help with logging the source of a query, C<< source >> can be set to the name of the script that requested the query. It is generally used along side C<< line >>.

=cut
sub query
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->query()" }});
	
	my $uuid   = $parameter->{uuid}   ? $parameter->{uuid}   : $anvil->data->{sys}{database}{read_uuid};
	my $line   = $parameter->{line}   ? $parameter->{line}   : __LINE__;
	my $query  = $parameter->{query}  ? $parameter->{query}  : "";
	my $secure = $parameter->{secure} ? $parameter->{secure} : 0;
	my $source = $parameter->{source} ? $parameter->{source} : $THIS_FILE;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                              => $uuid, 
		"cache::database_handle::${uuid}" => $anvil->data->{cache}{database_handle}{$uuid}, 
		line                              => $line, 
		query                             => (not $secure) ? $query : $anvil->Log->is_secure($query), 
		secure                            => $secure, 
		source                            => $source, 
	}});
	
	# Make logging code a little cleaner
	my $database_name = defined $anvil->data->{database}{$uuid}{name} ? $anvil->data->{database}{$uuid}{name} : $anvil->data->{sys}{database}{name};
	my $say_server    = $anvil->data->{database}{$uuid}{host}.":".$anvil->data->{database}{$uuid}{port}." -> ".$database_name;
	
	if (not $uuid)
	{
		# No database to talk to...
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0072"});
		return("!!error!!");
	}
	elsif (not defined $anvil->data->{cache}{database_handle}{$uuid})
	{
		# Database handle is gone.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0073", variables => { uuid => $uuid }});
		return("!!error!!");
	}
	if (not $query)
	{
		# No query
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0084", variables => { 
			server => $say_server,
		}});
		return("!!error!!");
	}
	
	# Test access to the DB before we do the actual query
	$anvil->Database->_test_access({debug => $debug, uuid => $uuid});
	
	# If I am still alive check if any locks need to be renewed.
	$anvil->Database->check_lock_age({debug => $debug});
	
	# Do I need to log the transaction?
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		"sys::database::log_transactions" => $anvil->data->{sys}{database}{log_transactions}, 
	}});
	if ($anvil->data->{sys}{database}{log_transactions})
	{
		$anvil->Log->entry({source => $source, line => $line, secure => $secure, level => 0, key => "log_0074", variables => { 
			uuid  => $anvil->data->{database}{$uuid}{host}, 
			query => $query, 
		}});
	}
	
	# Do the query.
	my $DBreq = $anvil->data->{cache}{database_handle}{$uuid}->prepare($query) or $anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0075", variables => { 
			query    => (not $secure) ? $query : $anvil->Log->is_secure($query), 
			server   => $say_server,
			db_error => $DBI::errstr, 
		}});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { DBreq => $DBreq }});
	
	# Execute on the query
	$DBreq->execute() or $anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0076", variables => { 
			query    => (not $secure) ? $query : $anvil->Log->is_secure($query), 
			server   => $say_server,
			db_error => $DBI::errstr, 
		}});
	
	# Return the array
	return($DBreq->fetchall_arrayref());
}


=head2 quote

This quotes a string for safe use in database queries/writes. It operates exactly as C<< DBI >>'s C<< quote >> method. This method is simply a wrapper that uses the C<< DBI >> handle set as the currently active read database.

Example;

 $anvil->Database->quote("foo");

B<< NOTE >>:

Unlike most Anvil methods, this one does NOT use hashes for the parameters! It is meant to replicate C<< DBI->quote("foo") >>, so the only passed-in value is the string to quote. If an undefined or empty string is passed in, a quoted empty string will be returned.

=cut
sub quote
{
	my $self   = shift;
	my $string = shift;
	my $anvil  = $self->parent;
	my $debug  = 2;
	
	   $string = "" if not defined $string;
	my $quoted = $anvil->Database->read->quote($string);
	
	return($quoted);
}


=head2 read

This method returns the active database handle used for reading. When C<< Database->connect() >> is called, it tries to find the local database (if available) and use that for reads. If there is no local database, then the first database successfully connected to is used instead.

Example setting a handle to use for future reads;

 $anvil->Database->read({set => $dbh});

Example, using the database handle to quote a string;

 $anvil->Database->read->quote("foo");

Parameters;

=head3 set (optional)

If used, the passed in value is set as the new handle to use for future reads. 

=cut
sub read
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	
	# We could be passed an empty string, which is the same as 'delete'.
	if (defined $parameter->{set})
	{
		if ($parameter->{set} eq "delete")
		{
			$anvil->data->{sys}{database}{use_handle} = "";
		}
		else
		{
			$anvil->data->{sys}{database}{use_handle} = $parameter->{set};
		}
	}
	elsif (not defined $anvil->data->{sys}{database}{use_handle})
	{
		$anvil->data->{sys}{database}{use_handle} = "";
	}
	
	return($anvil->data->{sys}{database}{use_handle});
}


=head2 read_variable

This reads a variable from the C<< variables >> table. Be sure to only use the reply from here to override what might have been set in a config file. This method always returns the data from the database itself.

The method returns an array reference containing, in order, the variable's value, database UUID and last modified date stamp.

If anything goes wrong, C<< !!error!! >> is returned. If the variable didn't exist in the database, an empty string will be returned for the UUID, value and modified date.

Parameters;

=head3 variable_uuid (optional)

If specified, this specifies the variable UUID to read. When this parameter is specified, the C<< variable_name >> parameter is ignored.

=head3 variable_name (required)

This is the name of the variable we're reading.

=head3 variable_source_table (optional)

If set along with C<< variable_source_uuid >>, the variable being read will be specified against this and the UUID.

=head3 variable_source_uuid (optional)

If set along with C<< variable_source_table >>, the variable being read will be specified against this and the source table.

=cut
sub read_variable
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->read_variable()" }});
	
	my $variable_uuid         = $parameter->{variable_uuid}         ? $parameter->{variable_uuid}         : "";
	my $variable_name         = $parameter->{variable_name}         ? $parameter->{variable_name}         : "";
	my $variable_source_uuid  = $parameter->{variable_source_uuid}  ? $parameter->{variable_source_uuid}  : "";
	my $variable_source_table = $parameter->{variable_source_table} ? $parameter->{variable_source_table} : "";
	my $uuid                  = $parameter->{uuid}                  ? $parameter->{uuid}                  : $anvil->data->{sys}{database}{read_uuid};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		variable_uuid         => $variable_uuid, 
		variable_name         => $variable_name, 
		variable_source_uuid  => $variable_source_uuid, 
		variable_source_table => $variable_source_table, 
	}});
	
	# Do we have either the 
	if ((not $variable_name) && (not $variable_uuid))
	{
		# Throw an error and exit.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0036"});
		return("!!error!!", "!!error!!", "!!error!!");
	}
	
	# If we don't have a UUID, see if we can find one for the given SMTP server name.
	my $query = "
SELECT 
    variable_value, 
    variable_uuid, 
    round(extract(epoch from modified_date)) AS mtime
FROM 
    variables 
WHERE ";
	if ($variable_uuid)
	{
		$query .= "
    variable_uuid = ".$anvil->Database->quote($variable_uuid);
	}
	else
	{
		$query .= "
    variable_name = ".$anvil->Database->quote($variable_name);
		if (($variable_source_uuid ne "") && ($variable_source_table ne ""))
		{
			$query .= "
AND 
    variable_source_uuid  = ".$anvil->Database->quote($variable_source_uuid)." 
AND 
    variable_source_table = ".$anvil->Database->quote($variable_source_table)." 
";
		}
	}
	$query .= ";";
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0124", variables => { query => $query }});
	
	my $variable_value = "";
	my $modified_date  = "";
	my $results        = $anvil->Database->query({uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__});
	my $count          = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		results => $results, 
		count   => $count,
	}});
	foreach my $row (@{$results})
	{
		$variable_value = $row->[0];
		$variable_uuid  = $row->[1];
		$modified_date  = $row->[2];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			variable_value => $variable_value, 
			variable_uuid  => $variable_uuid, 
			modified_date  => $modified_date, 
		}});
	}
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		variable_value => $variable_value, 
		variable_uuid  => $variable_uuid, 
		modified_date  => $modified_date, 
	}});
	return($variable_value, $variable_uuid, $modified_date);
}


=head2 refresh_timestamp

This refreshes C<< sys::database::timestamp >>. It returns C<< sys::database::timestamp >> as well.

This method takes no parameters.

=cut
sub refresh_timestamp
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->_test_access()" }});
	
	my $query = "SELECT cast(now() AS timestamp with time zone);";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
	
	$anvil->data->{sys}{database}{timestamp} = $anvil->Database->query({debug => $debug, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::timestamp" => $anvil->data->{sys}{database}{timestamp} }});
	
	return($anvil->data->{sys}{database}{timestamp});
}


=head2 resync_databases

This will resync the database data on this and peer database(s) if needed. It takes no arguments and will immediately return unless C<< sys::database::resync_needed >> was set.

=cut
sub resync_databases
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->resync_databases()" }});
	
	# If a resync isn't needed, just return. 
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 'sys::database::resync_needed' => $anvil->data->{sys}{database}{resync_needed} }});
	if (not $anvil->data->{sys}{database}{resync_needed})
	{
		# We don't need table data, clear it.
		delete $anvil->data->{sys}{database}{table};
		return(0);
	}
	
	# Archive old data before resync'ing
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0451"});
	$anvil->Database->archive_database({debug => $debug});
	
	### NOTE: Don't sort this array, we need to resync in the order that the user passed the tables to us
	###       to avoid trouble with primary/foreign keys.
	# We're going to use the array of tables assembles by _find_behind_databases() stored in 
	# 'sys::database::check_tables'
	foreach my $table (@{$anvil->data->{sys}{database}{check_tables}})
	{
		# We don't sync 'states' as it's transient and sometimes per-DB.
		next if $table eq "states";
		
		# If the 'schema' is 'public', there is no table in the history schema. If there is a host 
		# column, the resync will be restricted to entries from this host uuid.
		my $schema      = $anvil->data->{sys}{database}{table}{$table}{schema};
		my $host_column = $anvil->data->{sys}{database}{table}{$table}{host_column};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			table       => $table, 
			schema      => $schema, 
			host_column => $host_column, 
		}});
		
		# If there is a column name that is '<table>_uuid', or the same with the table's name minus 
		# the last 's' or 'es', this will be the UUID column to keep records linked in history. We'll
		# need to know this off the bat. Tables where we don't find a UUID column won't be sync'ed.
		my $column1 = $table."_uuid";
		my $column2 = "";
		my $column3 = "";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { column1 => $column1 }});
		if ($table =~ /^(.*)s$/)
		{
			$column2 = $1."_uuid";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { column2 => $column2 }});
		}
		if ($table =~ /^(.*)es$/)
		{
			$column3 = $1."_uuid";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { column3 => $column3 }});
		}
		my $query = "SELECT column_name FROM information_schema.columns WHERE table_catalog = ".$anvil->Database->quote($anvil->data->{sys}{database}{name})." AND table_schema = 'public' AND table_name = ".$anvil->Database->quote($table)." AND data_type = 'uuid' AND is_nullable = 'NO' AND column_name = ".$anvil->Database->quote($column1).";";
		if ($column3)
		{
			$query = "SELECT column_name FROM information_schema.columns WHERE table_catalog = ".$anvil->Database->quote($anvil->data->{sys}{database}{name})." AND table_schema = 'public' AND table_name = ".$anvil->Database->quote($table)." AND data_type = 'uuid' AND is_nullable = 'NO' AND (column_name = ".$anvil->Database->quote($column1)." OR column_name = ".$anvil->Database->quote($column2)." OR column_name = ".$anvil->Database->quote($column3).");";
		}
		elsif ($column2)
		{
			$query = "SELECT column_name FROM information_schema.columns WHERE table_catalog = ".$anvil->Database->quote($anvil->data->{sys}{database}{name})." AND table_schema = 'public' AND table_name = ".$anvil->Database->quote($table)." AND data_type = 'uuid' AND is_nullable = 'NO' AND (column_name = ".$anvil->Database->quote($column1)." OR column_name = ".$anvil->Database->quote($column2).");";
		}
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0124", variables => { query => $query }});
		my $uuid_column = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
		   $uuid_column = "" if not defined $uuid_column;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { uuid_column => $uuid_column }});
		next if not $uuid_column;
		
		# Get all the columns in this table.
		$query = "SELECT column_name, is_nullable, data_type FROM information_schema.columns WHERE table_schema = ".$anvil->Database->quote($schema)." AND table_name = ".$anvil->Database->quote($table)." AND column_name != 'history_id';";
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0124", variables => { query => $query }});
		
		my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
		my $count   = @{$results};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			results => $results, 
			count   => $count,
		}});
		foreach my $row (@{$results})
		{
			my $column_name = $row->[0];
			my $not_null    = $row->[1] eq "NO" ? 1 : 0;
			my $data_type   = $row->[2];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				column_name => $column_name, 
				not_null    => $not_null, 
				data_type   => $data_type,
			}});
			
			$anvil->data->{sys}{database}{table}{$table}{column}{$column_name}{not_null}  = $not_null;
			$anvil->data->{sys}{database}{table}{$table}{column}{$column_name}{data_type} = $data_type;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"sys::database::table::${table}::column::${column_name}::not_null"  => $anvil->data->{sys}{database}{table}{$table}{column}{$column_name}{not_null}, 
				"sys::database::table::${table}::column::${column_name}::data_type" => $anvil->data->{sys}{database}{table}{$table}{column}{$column_name}{data_type}, 
			}});
		}
		
		# Now read in the data from the different databases.
		foreach my $uuid (sort {$a cmp $b} keys %{$anvil->data->{cache}{database_handle}})
		{
			# ...
			$anvil->data->{db_resync}{$uuid}{public}{sql}  = [];
			$anvil->data->{db_resync}{$uuid}{history}{sql} = [];
			
			# Read in the data, modified_date first as we'll need that for all entries we record.
			my $query        = "SELECT DISTINCT modified_date AT time zone 'UTC' AS utc_modified_date, $uuid_column, ";
			my $read_columns = [];
			push @{$read_columns}, "modified_date";
			push @{$read_columns}, $uuid_column;
			foreach my $column_name (sort {$a cmp $b} keys %{$anvil->data->{sys}{database}{table}{$table}{column}})
			{
				# We'll skip the host column as we'll use it in the conditional.
				next if $column_name eq "modified_date";
				next if $column_name eq $host_column;
				next if $column_name eq $uuid_column;
				$query .= $column_name.", ";
				
				push @{$read_columns}, $column_name;
			}
			
			# Strip the last comma and the add the schema.table name.
			$query =~ s/, $/ /;
			$query .= "FROM ".$schema.".".$table;
			
			# Restrict to this host if a host column was found.
			if ($host_column)
			{
				$query .= " WHERE ".$host_column." = ".$anvil->Database->quote($anvil->data->{sys}{host_uuid});
			}
			$query .= " ORDER BY utc_modified_date DESC;";
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0074", variables => { uuid => $anvil->data->{database}{$uuid}{host}, query => $query }});
			
			my $results = $anvil->Database->query({uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count,
			}});
			next if not $count;
			
			my $row_number = 0;
			foreach my $row (@{$results})
			{
				   $row_number++;
				my $modified_date = "";
				my $row_uuid      = "";
				for (my $column_number = 0; $column_number < @{$read_columns}; $column_number++)
				{
					my $column_name  = $read_columns->[$column_number];
					my $column_value = defined $row->[$column_number] ? $row->[$column_number] : "NULL";
					my $not_null     = $anvil->data->{sys}{database}{table}{$table}{column}{$column_name}{not_null};
					my $data_type    = $anvil->data->{sys}{database}{table}{$table}{column}{$column_name}{data_type};
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						"s1:id"            => $uuid,
						"s2:row_number"    => $row_number,
						"s3:column_number" => $column_number,
						"s4:column_name"   => $column_name, 
						"s5:column_value"  => $column_value,
						"s6:not_null"      => $not_null,
						"s7:data_type"     => $data_type, 
					}});
					if (($not_null) && ($column_value eq "NULL"))
					{
						$column_value = "";
						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { column_value => $column_value }});
					}
					
					# The modified_date should be the first row.
					if ($column_name eq "modified_date")
					{
						$modified_date = $column_value;
						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { modified_date => $modified_date }});
						next;
					}
					
					# The row's UUID should be the second row.
					if ($column_name eq $uuid_column)
					{
						$row_uuid = $column_value;
						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { row_uuid => $row_uuid }});
						
						# This is used to determine if a given entry needs to be 
						# updated or inserted into the public schema
						$anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{'exists'} = 1;
						$anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{seen}     = 0;
						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
							"db_data::${uuid}::${table}::${uuid_column}::${row_uuid}::exists" => $anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{'exists'}, 
							"db_data::${uuid}::${table}::${uuid_column}::${row_uuid}::seen"   => $anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{seen}, 
						}});
						
						next;
					}
					
					# If we failed to get a modified_date, something went very wrong.
					if (not $modified_date)
					{
						$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "error_0114", variables => { query => $query }});
						$anvil->nice_exit({code => 1});
						die;
					}
					
					# If we don't have a row uuid, something has also gone wrong...
					if (not $row_uuid)
					{
						$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "error_0115", variables => { 
							uuid_column => $uuid_column, 
							query       => $query,
						}});
						$anvil->nice_exit({code => 1});
						die;
					}
					
					# Record this in the unified and local hashes.
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { row_uuid => $row_uuid }});
					
					$anvil->data->{db_data}{unified}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}{$column_name} = $column_value;
					$anvil->data->{db_data}{$uuid}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}{$column_name}   = $column_value;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						"db_data::unified::${table}::modified_date::${modified_date}::${uuid_column}::${row_uuid}::${column_name}" => $anvil->data->{db_data}{unified}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}{$column_name}, 
						"db_data::${uuid}::${table}::modified_date::${modified_date}::${uuid_column}::${row_uuid}::${column_name}" => $anvil->data->{db_data}{$uuid}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}{$column_name}, 
					}});
				}
			}
		}
		
		# Now all the data is read in, we can see what might be missing from each DB.
		foreach my $modified_date (sort {$b cmp $a} keys %{$anvil->data->{db_data}{unified}{$table}{modified_date}})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { modified_date => $modified_date }});
			foreach my $row_uuid (sort {$a cmp $b} keys %{$anvil->data->{db_data}{unified}{$table}{modified_date}{$modified_date}{$uuid_column}})
			{
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { row_uuid => $row_uuid }});
				
				foreach my $uuid (sort {$a cmp $b} keys %{$anvil->data->{cache}{database_handle}})
				{
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { uuid => $uuid }});
					
					# For each 'row_uuid' we see;
					# - Check if we've *seen* it before
					#   |- If not seen; See if it *exists* in the public schema yet.
					#   |  |- If so, check to see if the entry in the public schema is up to date.
					#   |  |  \- If not, _UPDATE_ public schema.
					#   |  \- If not, do an _INSERT_ into public schema.
					#   \- If we have seen, see if it exists at the current timestamp.
					#      \- If not, _INSERT_ it into history schema.
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						"db_data::${uuid}::${table}::${uuid_column}::${row_uuid}::seen" => $anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{seen}, 
					}});
					$anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{seen} = 0 if not defined $anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{seen};
					if (not $anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{seen})
					{
						# Mark this record as now having been seen.
						$anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{seen} = 1;
						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
							"db_data::${uuid}::${table}::${uuid_column}::${row_uuid}::seen" => $anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{seen}, 
						}});
						
						# Does it exist?
						$anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{'exists'} = 0 if not defined $anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{'exists'};
						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
							"db_data::${uuid}::${table}::${uuid_column}::${row_uuid}::exists" => $anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{'exists'}, 
						}});
						if ($anvil->data->{db_data}{$uuid}{$table}{$uuid_column}{$row_uuid}{'exists'})
						{
							# It exists, but does it exist at this time stamp?
							$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
								"db_data::${uuid}::${table}::modified_date::${modified_date}::${uuid_column}::${row_uuid}" => $anvil->data->{db_data}{$uuid}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}, 
							}});
							if (not $anvil->data->{db_data}{$uuid}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid})
							{
								# No, so UPDATE it. We'll build the query now...
								my $query = "UPDATE public.$table SET ";
								foreach my $column_name (sort {$a cmp $b} keys %{$anvil->data->{db_data}{unified}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}})
								{
									my $column_value =  $anvil->Database->quote($anvil->data->{db_data}{unified}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}{$column_name});
									   $column_value =  "NULL" if not defined $column_value;
									   $column_value =~ s/'NULL'/NULL/g;
									$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
										column_name  => $column_name, 
										column_value => $column_value, 
									}});
									
									$query .= "$column_name = ".$column_value.", ";
								}
								$query .= "modified_date = ".$anvil->Database->quote($modified_date)."::timestamp AT TIME ZONE 'UTC' WHERE $uuid_column = ".$anvil->Database->quote($row_uuid).";";
								$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0460", variables => { uuid => $anvil->data->{database}{$uuid}{host}, query => $query }});
								
								# Now record the query in the array
								push @{$anvil->data->{db_resync}{$uuid}{public}{sql}}, $query;
							} # if not exists - timestamp
						} # if exists
						else
						{
							# It doesn't exist, so INSERT it. We need to 
							# build entries for the column names and 
							# values at the same time to make certain 
							# they're in the same order.
							my $columns = "";
							my $values  = "";
							foreach my $column_name (sort {$a cmp $b} keys %{$anvil->data->{db_data}{unified}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}})
							{
								my $column_value =  $anvil->Database->quote($anvil->data->{db_data}{unified}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}{$column_name});
								   $column_value =~ s/'NULL'/NULL/g;
								$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
									column_name  => $column_name, 
									column_value => $column_value, 
								}});
								$columns .= $column_name.", ";
								$values  .= $column_value.", ";
							}
							$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
								columns  => $columns, 
								'values' => $values, 
							}});
							
							my $query = "INSERT INTO public.$table (".$uuid_column.", ".$columns."modified_date) VALUES (".$anvil->Database->quote($row_uuid).", ".$values.$anvil->Database->quote($modified_date)."::timestamp AT TIME ZONE 'UTC');";
							if ($host_column)
							{
								# Add the host column.
								$query = "INSERT INTO public.$table ($host_column, $uuid_column, ".$columns."modified_date) VALUES (".$anvil->Database->quote($anvil->data->{sys}{host_uuid}).", ".$anvil->Database->quote($row_uuid).", ".$values.$anvil->Database->quote($modified_date)."::timestamp AT TIME ZONE 'UTC');";
							}
							$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0460", variables => { uuid => $anvil->data->{database}{$uuid}{host}, query => $query }});
							
							### NOTE: On some occasions, for as-yet unknown 
							###       reasons, a record can end up in the public 
							###       schema while nothing exists in the history 
							###       schema (which is what we read during a 
							###       resync). To deal with this, we'll do an
							###       explicit check before confirming the 
							###       INSERT)
							my $count_query = "SELECT COUNT(*) FROM public.".$table." WHERE ".$uuid_column." = ".$anvil->Database->quote($row_uuid).";";
							$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count_query => $count_query }});
							my $count = $anvil->Database->query({debug => $debug, uuid => $uuid, query => $count_query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
							$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count => $count }});
							if ($count)
							{
								# Already in, redirect to the history schema.
								$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, priority => "alert", key => "warning_0029", variables => { 
									table     => $table, 
									host_name => $anvil->Database->get_host_from_uuid({short => 1, host_uuid => $uuid}), 
									host_uuid => $uuid, 
									column    => $uuid_column, 
									uuid      => $row_uuid, 
									query     => $query, 
								}});
								$query =~ s/INSERT INTO public./INSERT INTO history./;
								
								push @{$anvil->data->{db_resync}{$uuid}{history}{sql}}, $query;
							}
							else
							{
								# No problem, record the query in the array
								push @{$anvil->data->{db_resync}{$uuid}{public}{sql}}, $query;
							}
						} # if not exists
					} # if not seen
					else
					{
						### NOTE: If the table doesn't have a history schema,
						###       we skip this.
						next if $schema eq "public";
						
						# We've seen this row_uuid before, so it is just a 
						# question of whether the entry for the current 
						# timestamp exists in the history schema.
						$anvil->data->{db_data}{$uuid}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid} = 0 if not defined $anvil->data->{db_data}{$uuid}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid};
						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
							"db_data::${uuid}::${table}::modified_date::${modified_date}::${uuid_column}::${row_uuid}" => $anvil->data->{db_data}{$uuid}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}, 
						}});
						if (not $anvil->data->{db_data}{$uuid}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid})
						{
							# It hasn't been seen, so INSERT it. We need 
							# to build entries for the column names and 
							# values at the same time to make certain 
							# they're in the same order.
							my $columns = "";
							my $values  = "";
							foreach my $column_name (sort {$a cmp $b} keys %{$anvil->data->{db_data}{unified}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}})
							{
								my $column_value =  $anvil->Database->quote($anvil->data->{db_data}{unified}{$table}{modified_date}{$modified_date}{$uuid_column}{$row_uuid}{$column_name});
									$column_value =~ s/'NULL'/NULL/g;
								$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
									column_name  => $column_name, 
									column_value => $column_value, 
								}});
								$columns .= $column_name.", ";
								$values  .= $column_value.", ";
							}
							$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
								columns  => $columns, 
								'values' => $values, 
							}});
							
							my $query = "INSERT INTO history.$table (".$uuid_column.", ".$columns."modified_date) VALUES (".$anvil->Database->quote($row_uuid).", ".$values.$anvil->Database->quote($modified_date)."::timestamp AT TIME ZONE 'UTC');";
							if ($host_column)
							{
								# Add the host column.
								$query = "INSERT INTO history.$table ($host_column, $uuid_column, ".$columns."modified_date) VALUES (".$anvil->Database->quote($anvil->data->{sys}{host_uuid}).", ".$anvil->Database->quote($row_uuid).", ".$values.$anvil->Database->quote($modified_date)."::timestamp AT TIME ZONE 'UTC');";
							}
							$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0460", variables => { uuid => $anvil->data->{database}{$uuid}{host}, query => $query }});
							
							# Now record the query in the array
							push @{$anvil->data->{db_resync}{$uuid}{history}{sql}}, $query;
						} # if not exists - timestamp
					} # if seen
				} # foreach $uuid
			} # foreach $row_uuid
		} # foreach $modified_date ...
		
		# Free up memory by deleting the DB data from the main hash.
		delete $anvil->data->{db_data};
		
		# Do the INSERTs now and then release the memory.
		foreach my $uuid (sort {$a cmp $b} keys %{$anvil->data->{cache}{database_handle}})
		{
			# Merge the queries for both schemas into one array, with public schema 
			# queries being first, then delete the arrays holding them to free memory
			# before we start the resync.
			my $merged = [];
			@{$merged} = (@{$anvil->data->{db_resync}{$uuid}{public}{sql}}, @{$anvil->data->{db_resync}{$uuid}{history}{sql}});
			undef $anvil->data->{db_resync}{$uuid}{public}{sql};
			undef $anvil->data->{db_resync}{$uuid}{history}{sql};
			
			# If the merged array has any entries, push them in.
			my $to_write_count = @{$merged};
			if ($to_write_count > 0)
			{
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0221", variables => { 
					to_write  => $anvil->Convert->add_commas({number => $to_write_count}),
					table     => $table, 
					host_name => $anvil->Get->host_name({host_uuid => $uuid}), 
				}});
				$anvil->Database->write({debug => $debug, uuid => $uuid, query => $merged, source => $THIS_FILE, line => __LINE__});
				undef $merged;
			}
		}
	} # foreach my $table
	
	# We're done with the table data, clear it.
	delete $anvil->data->{sys}{database}{table};
	
	# Clear the variable that indicates we need a resync.
	$anvil->data->{sys}{database}{resync_needed} = 0;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 'sys::database::resync_needed' => $anvil->data->{sys}{database}{resync_needed} }});
	
	return(0);
}


=head2 write

This records data to one or all of the databases. If an ID is passed, the query is written to one database only. Otherwise, it will be written to all DBs.

=cut
sub write
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->write()" }});
	
	my $uuid    = $parameter->{uuid}    ? $parameter->{uuid}   : "";
	my $line    = $parameter->{line}    ? $parameter->{line}   : __LINE__;
	my $query   = $parameter->{query}   ? $parameter->{query}  : "";
	my $secure  = $parameter->{secure}  ? $parameter->{secure} : 0;
	my $source  = $parameter->{source}  ? $parameter->{source} : $THIS_FILE;
	my $reenter = $parameter->{reenter} ? $parameter->{reenter} : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid    => $uuid, 
		line    => $line, 
		query   => (not $secure) ? $query : $anvil->Log->is_secure($query), 
		secure  => $secure, 
		source  => $source, 
		reenter => $reenter,
	}});
	
	if ($uuid)
	{
		$anvil->data->{cache}{database_handle}{$uuid} = "" if not defined $anvil->data->{cache}{database_handle}{$uuid};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"cache::database_handle::${uuid}" => $anvil->data->{cache}{database_handle}{$uuid}, 
		}});
	}
	
	### NOTE: The careful checks below are to avoid autovivication biting our arses later.
	# Make logging code a little cleaner
	my $database_name = $anvil->data->{sys}{database}{name};
	my $say_server    = $anvil->Words->string({key => "log_0129"});
	if (($uuid) && (exists $anvil->data->{database}{$uuid}) && (defined $anvil->data->{database}{$uuid}{name}) && ($anvil->data->{database}{$uuid}{name}))
	{
		$database_name = $anvil->data->{database}{$uuid}{name};
		$say_server    = $anvil->data->{database}{$uuid}{host}.":".$anvil->data->{database}{$uuid}{port}." -> ".$database_name;
	}
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		database_name => $database_name, 
		say_server    => $say_server,
	}});
	
	# We don't check if ID is set here because not being set simply means to write to all available DBs.
	if (not $query)
	{
		# No query
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0085", variables => { server => $say_server }});
		return("!!error!!");
	}
	
	# If I am still alive check if any locks need to be renewed.
	$anvil->Database->check_lock_age({debug => $debug});
	
	# This array will hold either just the passed DB ID or all of them, if no ID was specified.
	my @db_uuids;
	if ($uuid)
	{
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { uuid => $uuid }});
		push @db_uuids, $uuid;
	}
	else
	{
		foreach my $uuid (sort {$a cmp $b} keys %{$anvil->data->{cache}{database_handle}})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { uuid => $uuid }});
			push @db_uuids, $uuid;
		}
	}
	
	# Sort out if I have one or many queries.
	my $limit     = 25000;
	my $count     = 0;
	my $query_set = [];
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::maximum_batch_size" => $anvil->data->{sys}{database}{maximum_batch_size} }});
	if ($anvil->data->{sys}{database}{maximum_batch_size})
	{
		if ($anvil->data->{sys}{database}{maximum_batch_size} =~ /\D/)
		{
			# Bad value.
			$anvil->data->{sys}{database}{maximum_batch_size} = 25000;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::maximum_batch_size" => $anvil->data->{sys}{database}{maximum_batch_size} }});
		}
		
		# Use the set value now.
		$limit = $anvil->data->{sys}{database}{maximum_batch_size};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { limit => $limit }});
	}
	if (ref($query) eq "ARRAY")
	{
		# Multiple things to enter.
		$count = @{$query};
		
		# If I am re-entering, then we'll proceed normally. If not, and if we have more than 10k 
		# queries, we'll split up the queries into 10k chunks and re-enter.
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			count   => $count, 
			limit   => $limit, 
			reenter => $reenter, 
		}});
		if (($count > $limit) && (not $reenter))
		{
			my $i    = 0;
			my $next = $limit;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { i => $i, 'next' => $next }});
			foreach my $this_query (@{$query})
			{
				push @{$query_set}, $this_query;
				$i++;
				
				if ($i > $next)
				{
					# Commit this batch.
					foreach my $uuid (@db_uuids)
					{
						# Commit this chunk to this DB.
						$anvil->Database->write({uuid => $uuid, query => $query_set, source => $THIS_FILE, line => $line, reenter => 1});
						
						### TODO: Rework this so that we exit here (so that we can 
						###       send an alert) if the RAM use is too high.
						# This can get memory intensive, so check our RAM usage and 
						# bail if we're eating too much.
						my $ram_use = $anvil->System->check_memory({program_name => $THIS_FILE});
						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { ram_use => $ram_use }});
						
						# Wipe out the old set array, create it as a new anonymous array and reset 'i'.
						undef $query_set;
						$query_set =  [];
						$i         =  0;
					}
				}
			}
		}
		else
		{
			# Not enough to worry about or we're dealing with a chunk, proceed as normal.
			foreach my $this_query (@{$query})
			{
				push @{$query_set}, $this_query;
			}
		}
	}
	else
	{
		push @{$query_set}, $query;
		my $query_set_count = @{$query_set};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query_set_count => $query_set_count }});
	}
	
	my $db_uuids_count = @db_uuids;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { db_uuids_count => $db_uuids_count }});
	foreach my $uuid (@db_uuids)
	{
		# Test access to the DB before we do the actual query
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { uuid => $uuid }});
		$anvil->Database->_test_access({debug => $debug, uuid => $uuid});
		
		# Do the actual query(ies)
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			uuid  => $uuid, 
			count => $count, 
		}});
		if ($count)
		{
			# More than one query, so start a transaction block.
			$anvil->data->{cache}{database_handle}{$uuid}->begin_work;
		}
		
		foreach my $query (@{$query_set})
		{
			if ($anvil->data->{sys}{database}{log_transactions})
			{
				$anvil->Log->entry({source => $source, line => $line, secure => $secure, level => 0, key => "log_0083", variables => { 
					uuid  => $uuid, 
					query => $query, 
				}});
			}
			
			if (not $anvil->data->{cache}{database_handle}{$uuid})
			{
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0089", variables => { uuid => $uuid }});
				next;
			}
			
			# Do the do.
			$anvil->data->{cache}{database_handle}{$uuid}->do($query) or $anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0090", variables => { 
					query    => (not $secure) ? $query : $anvil->Log->is_secure($query), 
					server   => $say_server,
					db_error => $DBI::errstr, 
				}});
		}
		
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count => $count }});
		if ($count)
		{
			# Commit the changes.
			$anvil->data->{cache}{database_handle}{$uuid}->commit();
		}
	}
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count => $count }});
	if ($count)
	{
		# Free up some memory.
		undef $query_set;
	}
	
	return(0);
}

# =head3
# 
# Private Functions;
# 
# =cut

#############################################################################################################
# Private functions                                                                                         #
#############################################################################################################

=head2 _archive_table

NOTE: Not implemented yet (will do so once enough records are in the DB.)

This takes a table name 

This takes a table to check to see if old records need to be archived the data from the history schema to a plain-text dump. 

B<NOTE>: If we're asked to use an offset that is too high, we'll go into a loop and may end up doing some empty loops. We don't check to see if the offset is sensible, though setting it too high won't cause the archive operation to fail, but it won't chunk as expected.

B<NOTE>: The archive process works on all records, B<NOT> restricted to records referencing this host via a C<< *_host_uuid >> column.  

Parameters;

=head3 table <required>

This is the table that will be archived, if needed. 

An archive will be deemed required if there are more than C<< sys::database::archive::trigger >> records (default is C<< 100000 >>) in the table's C<< history >> schema. If this is set to C<< 0 >>, archiving will be disabled.

Individual tables can have custom triggers by setting C<< sys::database::archive::tables::<table>::trigger >>.

=cut
sub _archive_table
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->_archive_table()" }});
	
	my $table = $parameter->{table} ? $parameter->{table} : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		table => $table, 
	}});
	
	if (not $table)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Convert->_archive_table()", parameter => "table" }});
		return("!!error!!");
	}
	
	# We don't archive the OUI table, it generally has more entries than needed to trigger the archive, but it's needed.
	if ($table eq "oui")
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0459", variables => { table => $table }});
		return(0);
	}
	
	# These values are sanity checked before this method is called.
	my $compress   = $anvil->data->{sys}{database}{archive}{compress};
	my $directory  = $anvil->data->{sys}{database}{archive}{directory};
	my $drop_to    = $anvil->data->{sys}{database}{archive}{count};
	my $division   = $anvil->data->{sys}{database}{archive}{division};
	my $trigger    = $anvil->data->{sys}{database}{archive}{trigger};
	my $time_stamp = $anvil->Get->date_and_time({file_name => 1});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		compress   => $compress, 
		directory  => $directory, 
		drop_to    => $drop_to, 
		division   => $division, 
		trigger    => $trigger, 
		time_stamp => $time_stamp, 
	}});
	
	# Loop through each database so that we archive from everywhere before resync'ing.
	foreach my $uuid (keys %{$anvil->data->{database}})
	{
		# First, if this table doesn't have a history schema, exit.
		my $vacuum = 0;
		my $query  = "SELECT COUNT(*) FROM information_schema.tables WHERE table_type = 'BASE TABLE' AND table_schema = 'history' AND table_name = ".$anvil->Database->quote($table).";";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		my $count = $anvil->Database->query({debug => $debug, uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count => $count }});
		if (not $count)
		{
			# History table doesn't exist, we're done.
			next;
		}
		
		# Before we do any real analysis, do we have enough entries in the history schema to trigger an archive?
		$query = "SELECT COUNT(*) FROM history.".$table.";";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
		
		$count = $anvil->Database->query({debug => $debug, uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"s1:uuid"  => $uuid,
			"s2:count" => $count,
		}});
		if ($count <= $trigger)
		{
			# Not enough records to bother archiving.
			next;
		}
		
		# Do some math...
		my $to_remove        = $count - $drop_to;
		my $loops            = (int($to_remove / $division) + 1);
		my $records_per_loop = $anvil->Convert->round({number => ($to_remove / $loops)});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"s1:to_remove"        => $to_remove,
			"s2:loops"            => $loops,
			"s3:records_per_loop" => $records_per_loop,
		}});
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0453", variables => { 
			records => $anvil->Convert->add_commas({number => $to_remove }),
			loops   => $anvil->Convert->add_commas({number => $loops }),
			table   => $table,
			host    => $anvil->Database->get_host_from_uuid({short => 1, host_uuid => $uuid}),
		}});
		
		# There is enough data to trigger an archive, so lets get started with a list of columns in 
		# this table.
		$query = "SELECT column_name FROM information_schema.columns WHERE table_schema = 'history' AND table_name = ".$anvil->Database->quote($table)." AND column_name != 'history_id' AND column_name != 'modified_date';";
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0124", variables => { query => $query }});
		
		my $columns      = $anvil->Database->query({debug => $debug, uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__});
		my $column_count = @{$columns};
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			columns      => $columns, 
			column_count => $column_count 
		}});
		
		my $offset = $count - $records_per_loop;
		my $loop   = 0;
		for (1..$loops)
		{
			# We need to date stamp from the closest record to the offset.
			   $loop++;
			my $sql_file = "
-- Dump created at: [".$anvil->Get->date_and_time()."]
SET statement_timeout = 0;
SET lock_timeout = 0;
SET idle_in_transaction_session_timeout = 0;
SET client_encoding = 'UTF8';
SET standard_conforming_strings = on;
SELECT pg_catalog.set_config('search_path', '', false);
SET check_function_bodies = false;
SET client_min_messages = warning;
SET row_security = off;

COPY history.".$table." (";
			my $query = "SELECT modified_date FROM history.".$table." ORDER BY modified_date ASC OFFSET ".$offset." LIMIT 1;";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"s1:loop"     => $loop,
				"s2:query"    => $query,
				"s3:sql_file" => $sql_file,
			}});
			
			my $modified_date = $anvil->Database->query({debug => $debug, uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { modified_date => $modified_date }});
			
			# Build the query.
			$query = "SELECT ";
			foreach my $column (sort {$a cmp $b} @{$columns})
			{
				$sql_file .= $column->[0].", ";
				$query    .= $column->[0].", ";
			}
			$sql_file .= "modified_date) FROM stdin;\n";
			$query    .= "modified_date FROM history.".$table." WHERE modified_date >= '".$modified_date."' ORDER BY modified_date ASC;";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				sql_file => $sql_file,
				query    => $query,
			}});
			my $results = $anvil->Database->query({debug => $debug, uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__});
			my $count   = @{$results};
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				results => $results, 
				count   => $count, 
			}});
			
			foreach my $row (@{$results})
			{
				# Build the string.
				my $line = "";
				my $i    = 0;
				foreach my $column (@{$columns})
				{
					my $value = defined $row->[$i] ? $row->[$i] : '\N';
					$i++;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						"s1:i"      => $i, 
						"s2:column" => $column, 
						"s3:value"  => $value, 
					}});
					
					# We need to convert tabs and newlines into \t and \n
					$value =~ s/\t/\\t/g;
					$value =~ s/\n/\\n/g;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { value => $value }});
					
					$line .= $value."\t";
				}
				# Add the modified_date column.
				$line .= $row->[$i]."\n";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { line => $line }});
				
				$sql_file .= $line;
			}
			$sql_file .= "\\.\n\n";;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { sql_file => $sql_file }});
			
			my $archive_file =  $directory."/".$anvil->Database->get_host_from_uuid({short => 1, host_uuid => $uuid}).".".$table.".".$time_stamp.".".$loop.".out";
			   $archive_file =~ s/\/\//\//g;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { archive_file => $archive_file }});
			
			# It may not be secure, but we play it safe.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0454", variables => { 
				records => $anvil->Convert->add_commas({number => $count}),
				file    => $archive_file,
			}});
			my ($failed) = $anvil->Storage->write_file({
				debug  => $debug, 
				body   => $sql_file,
				file   => $archive_file, 
				user   => "root", 
				group  => "root", 
				mode   => "0600",
				secure => 1.
			});
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { failed => $failed }});
			
			if ($failed)
			{
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "error_0099", variables => { 
					file  => $archive_file,
					table => $table, 
				}});
				last;
			}
			else
			{
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0283"});
				$vacuum = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				if ($compress)
				{
					# Whether the compression works or not doesn't break archiving, so we
					# don't care if this fails.
					my ($failed) = $anvil->Storage->compress({
						debug => $debug,
						file  => $archive_file,
					});
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { failed => $failed }});
				}
				
				# Now actually remove the data.
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0457"});
				my $query = "DELETE FROM history.".$table." WHERE modified_date >= '".$modified_date."';";
				$anvil->Database->write({debug => $debug, uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__});
			}
			
			$offset -= $records_per_loop;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { offset => $offset }});
			
		}
		
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { vacuum => $vacuum }});
		if ($vacuum)
		{
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0458"});
			my $query = "VACUUM FULL;";
			$anvil->Database->write({debug => $debug, uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__});
		}
	}
	
	return(0);
}


=head2 _find_behind_databases

This returns the most up to date database ID, the time it was last updated and an array or DB IDs that are behind.

If there is a problem, C<< !!error!! >> is returned.

Parameters;

=head3 source (required)

This is used the same as in C<< Database->connect >>'s C<< source >> parameter. Please read that for usage information.

=head3 tables (optional)

This is used the same as in C<< Database->connect >>'s C<< tables >> parameter. Please read that for usage information.

=cut
sub _find_behind_databases
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->_find_behind_databases()" }});
	
	my $source = defined $parameter->{source} ? $parameter->{source} : "";
	my $tables = defined $parameter->{tables} ? $parameter->{tables} : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		source => $source, 
		tables => $tables, 
	}});
	
	# This should always be set, but just in case...
	if (not $source)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->_find_behind_databases()", parameter => "source" }});
		return("!!error!!");
	}
	
	# Make sure I've got an array of tables.
	if (ref($tables) ne "ARRAY")
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0218", variables => { name => "tables", value => $tables }});
		return("!!error!!");
	}
	
	# Now, look through the core tables, plus any tables the user might have passed, for differing 
	# 'modified_date' entries, or no entries in one DB with entries in the other (as can happen with a 
	# newly setup db).
	$anvil->data->{sys}{database}{check_tables} = [];
	
	### NOTE: Don't sort this! Tables need to be resynced in a specific order!
	# Loop through and resync the tables.
	foreach my $table (@{$tables})
	{
		# Record the table in 'sys::database::check_tables' array for later use in archive and 
		# resync methods.
		push @{$anvil->data->{sys}{database}{check_tables}}, $table;
		
		# Preset all tables to have an initial 'modified_date' and 'row_count' of 0.
		$anvil->data->{sys}{database}{table}{$table}{last_updated} = 0;
		$anvil->data->{sys}{database}{table}{$table}{row_count}    = 0;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"sys::database::table::${table}::last_updated" => $anvil->data->{sys}{database}{table}{$table}{last_updated},
		}});
	}
	
	# Look at all the databases and find the most recent time stamp (and the ID of the DB).
	my $source_updated_time = 0;
	foreach my $uuid (keys %{$anvil->data->{database}})
	{
		my $database_name = defined $anvil->data->{database}{$uuid}{name} ? $anvil->data->{database}{$uuid}{name} : "#!string!log_0185!#";
		my $database_user = defined $anvil->data->{database}{$uuid}{user} ? $anvil->data->{database}{$uuid}{user} : "#!string!log_0185!#";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"database::${uuid}::host"     => $anvil->data->{database}{$uuid}{host},
			"database::${uuid}::port"     => $anvil->data->{database}{$uuid}{port},
			"database::${uuid}::name"     => $database_name,
			"database::${uuid}::user"     => $database_user, 
			"database::${uuid}::password" => $anvil->Log->secure ? $anvil->data->{database}{$uuid}{password} : $anvil->Words->string({key => "log_0186"}), 
		}});
		
		# Loop through the tables in this DB. For each table, we'll record the most recent time 
		# stamp. Later, We'll look through again and any table/DB with an older time stamp will be 
		# behind and a resync will be needed.
		foreach my $table (@{$anvil->data->{sys}{database}{check_tables}})
		{
			# We don't sync 'states' as it's transient and sometimes per-DB.
			next if $table eq "states";
			
			# Does this table exist yet?
			my $query = "SELECT COUNT(*) FROM information_schema.tables WHERE table_type = 'BASE TABLE' AND table_schema = 'public' AND table_name = ".$anvil->Database->quote($table).";";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
			
			my $count = $anvil->Database->query({uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count => $count }});
			
			if ($count == 1)
			{
				# Does this table have a '*_host_uuid' column?
				my $query = "SELECT column_name FROM information_schema.columns WHERE table_schema = 'public' AND column_name LIKE '\%_host_uuid' AND table_name = ".$anvil->Database->quote($table).";";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				
				# See if there is a column that ends in '_host_uuid'. If there is, we'll use 
				# it later to restrict resync activity to these columns with the local 
				# 'sys::host_uuid'.
				my $host_column = $anvil->Database->query({uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
				   $host_column = "" if not defined $host_column;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_column => $host_column }});
				
				# Does this table have a history schema version?
				$query = "SELECT COUNT(*) FROM information_schema.tables WHERE table_type = 'BASE TABLE' AND table_schema = 'history' AND table_name = ".$anvil->Database->quote($table).";";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
				
				my $count = $anvil->Database->query({uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__})->[0]->[0];
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { count => $count }});
				
				my $schema = $count ? "history" : "public";
				   $query  =  "
SELECT DISTINCT 
    round(extract(epoch from modified_date)) AS unix_modified_date 
FROM 
    ".$schema.".".$table." ";
				if ($host_column)
				{
					$query .= "
WHERE 
    ".$host_column." = ".$anvil->Database->quote($anvil->data->{sys}{host_uuid}) ;
				}
				$query .= "
ORDER BY 
    unix_modified_date DESC
;";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					uuid  => $uuid, 
					query => $query, 
				}});
				
				# Get the count of columns as well as the most recent one.
				my $results   = $anvil->Database->query({uuid => $uuid, query => $query, source => $THIS_FILE, line => __LINE__});
				my $row_count = @{$results};
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					results   => $results, 
					row_count => $row_count, 
				}});
				
				my $last_updated = $results->[0]->[0];
				   $last_updated = 0 if not defined $last_updated;
				
				# Record this table's last modified_date for later comparison. We'll also 
				# record the schema and host column, if found, to save looking the same thing
				# up later if we do need a resync.
				$anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{last_updated} = $last_updated;
				$anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{row_count}    = $row_count;
				$anvil->data->{sys}{database}{table}{$table}{schema}                  = $schema;
				$anvil->data->{sys}{database}{table}{$table}{host_column}             = $host_column;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					"sys::database::table::${table}::uuid::${uuid}::last_updated" => $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{last_updated}, 
					"sys::database::table::${table}::uuid::${uuid}::row_count"    => $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{row_count}, 
					"sys::database::table::${table}::last_updated"                => $anvil->data->{sys}{database}{table}{$table}{last_updated},
					"sys::database::table::${table}::schema"                      => $anvil->data->{sys}{database}{table}{$table}{schema},
					"sys::database::table::${table}::host_column"                 => $anvil->data->{sys}{database}{table}{$table}{host_column},
				}});
				
				if ($anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{row_count} > $anvil->data->{sys}{database}{table}{$table}{row_count})
				{
					$anvil->data->{sys}{database}{table}{$table}{row_count} = $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{row_count};
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						"sys::database::table::${table}::row_count" => $anvil->data->{sys}{database}{table}{$table}{row_count}, 
					}});
				}
				
				if ($anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{last_updated} > $anvil->data->{sys}{database}{table}{$table}{last_updated})
				{
					$anvil->data->{sys}{database}{table}{$table}{last_updated} = $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{last_updated};
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
						"sys::database::table::${table}::last_updated" => $anvil->data->{sys}{database}{table}{$table}{last_updated}, 
					}});
				}
			}
		}
	}
	
	# Now loop through each table we've seen and see if the moditied_date differs for any of the 
	# databases. If it has, trigger a resync.
	foreach my $table (sort {$a cmp $b} keys %{$anvil->data->{sys}{database}{table}})
	{
		# We don't sync 'states' as it's transient and sometimes per-DB.
		next if $table eq "states";
		
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
			"sys::database::table::${table}::last_updated" => $anvil->data->{sys}{database}{table}{$table}{last_updated}, 
			"sys::database::table::${table}::row_count"    => $anvil->data->{sys}{database}{table}{$table}{row_count}, 
		}});
		foreach my $uuid (sort {$a cmp $b} keys %{$anvil->data->{sys}{database}{table}{$table}{uuid}})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"sys::database::table::${table}::uuid::${uuid}::last_updated" => $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{last_updated}, 
				"sys::database::table::${table}::uuid::${uuid}::row_count"    => $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{row_count}, 
			}});
			if ($anvil->data->{sys}{database}{table}{$table}{last_updated} > $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{last_updated})
			{
				# Resync needed.
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					"sys::database::table::${table}::last_updated"                => $anvil->data->{sys}{database}{table}{$table}{last_updated}, 
					"sys::database::table::${table}::uuid::${uuid}::last_updated" => $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{last_updated}, 
				}});
				my $difference = $anvil->Convert->add_commas({number => ($anvil->data->{sys}{database}{table}{$table}{last_updated} - $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{last_updated}) });
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, priority => "alert", key => "log_0106", variables => { 
					seconds => $difference, 
					table   => $table, 
					uuid    => $uuid,
					host    => $anvil->Get->host_name({host_uuid => $uuid}),
				}});
				
				# Mark it as behind.
				$anvil->Database->_mark_database_as_behind({debug => $debug, uuid => $uuid});
				last;
			}
			elsif ($anvil->data->{sys}{database}{table}{$table}{row_count} > $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{row_count})
			{
				# Resync needed.
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
					"sys::database::table::${table}::row_count"                => $anvil->data->{sys}{database}{table}{$table}{row_count}, 
					"sys::database::table::${table}::uuid::${uuid}::row_count" => $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{row_count}, 
				}});
				my $difference = $anvil->Convert->add_commas({number => ($anvil->data->{sys}{database}{table}{$table}{row_count} - $anvil->data->{sys}{database}{table}{$table}{uuid}{$uuid}{row_count}) });
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, priority => "alert", key => "log_0219", variables => { 
					missing => $difference, 
					table   => $table, 
					uuid    => $uuid,
					host    => $anvil->Get->host_name({host_uuid => $uuid}),
				}});
				
				# Mark it as behind.
				$anvil->Database->_mark_database_as_behind({debug => $debug, uuid => $uuid});
				last;
			}
		}
		last if $anvil->data->{sys}{database}{resync_needed};
	}
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::resync_needed" => $anvil->data->{sys}{database}{resync_needed} }});
	
	return(0);
}


=head2 _mark_database_as_behind

This method marks that a resync is needed and, if needed, switches the database this machine will read from.

Parameters;

=head3 id

This is the C<< id >> of the database being marked as "behind".

=cut
sub _mark_database_as_behind
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->_mark_database_as_behind()" }});
	
	
	my $uuid = $parameter->{uuid} ? $parameter->{uuid} : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { uuid => $uuid }});
	
	$anvil->data->{sys}{database}{to_update}{$uuid}{behind} = 1;
	$anvil->data->{sys}{database}{resync_needed}            = 1;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		"sys::database::to_update::${uuid}::behind" => $anvil->data->{sys}{database}{to_update}{$uuid}{behind}, 
		"sys::database::resync_needed"              => $anvil->data->{sys}{database}{resync_needed}, 
	}});
		
	# We can't trust this database for reads, so switch to another database for reads if
	# necessary.
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
		uuid                       => $uuid, 
		"sys::database::read_uuid" => $anvil->data->{sys}{database}{read_uuid}, 
	}});
	if ($uuid eq $anvil->data->{sys}{database}{read_uuid})
	{
		# Switch.
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { ">> sys::database::read_uuid" => $anvil->data->{sys}{database}{read_uuid} }});
		foreach my $this_uuid (sort {$a cmp $b} keys %{$anvil->data->{database}})
		{
			next if $this_uuid eq $uuid;
			$anvil->data->{sys}{database}{read_uuid} = $this_uuid;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "<< sys::database::read_uuid" => $anvil->data->{sys}{database}{read_uuid} }});
			last;
		}
	}
	
	return(0);
}


=head2 _test_access

This method takes a database UUID and tests the connection to it using the DBD 'ping' method. If it fails, open references to the database are removed or replaced, then an attempt to reconnect is made.

This exists to handle the loss of a database mid-run where a normal query, which isn't wrapped in a query, could hang indefinately.

=cut
sub _test_access
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->_test_access()" }});
	
	my $uuid = $parameter->{uuid} ? $parameter->{uuid} : "";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { uuid => $uuid }});
	
	# Make logging code a little cleaner
	my $database_name = defined $anvil->data->{database}{$uuid}{name} ? $anvil->data->{database}{$uuid}{name} : $anvil->data->{sys}{database}{name};
	my $say_server    = $anvil->data->{database}{$uuid}{host}.":".$anvil->data->{database}{$uuid}{port}." -> ".$database_name;
	
	# Log our test
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0087", variables => { server => $say_server }});
	
	# TODO: Is there a use for this anymore?
	if (0)
	{
		# Ping works. Try a quick test query.
		my $query = "SELECT 1";
		my $DBreq = $anvil->data->{cache}{database_handle}{$uuid}->prepare($query) or $anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0075", variables => { 
				query    => $query, 
				server   => $say_server,
				db_error => $DBI::errstr, 
			}});
		
		# Give the test query a few seconds to respond, just in case we have some latency to a remote DB.
		alarm(10);
		$DBreq->execute() or $anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0076", variables => { 
				query    => $query, 
				server   => $say_server,
				db_error => $DBI::errstr, 
			}});
		# If we're here, we made contact.
		alarm(0);
	}
	
	# Check using ping. Returns '1' on success, '0' on fail.
	my $connected = $anvil->data->{cache}{database_handle}{$uuid}->ping();
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { connected => $connected }});
	if (not $connected)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0192", variables => { server => $say_server }});
		
		# Try to reconnect.
		$anvil->data->{sys}{database}{connections}--;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::connections" => $anvil->data->{sys}{database}{connections} }});
		
		# If this was the DB we were reading from or that the use_db_handle matches, and another DB 
		# appears to still be up, switch to one of the others.
		if ($anvil->data->{sys}{database}{connections})
		{
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				"sys::database::use_handle"       => $anvil->Database->read,
				"cache::database_handle::${uuid}" => $anvil->data->{cache}{database_handle}{$uuid},
			}});
			if ($anvil->Database->read eq $anvil->data->{cache}{database_handle}{$uuid})
			{
				foreach my $this_uuid (keys %{$anvil->data->{cache}{database_handle}})
				{
					# We don't test this connection because, if it's down, we'll know 
					# when it is tested.
					my $database_name = defined $anvil->data->{database}{$this_uuid}{name} ? $anvil->data->{database}{$this_uuid}{name} : $anvil->data->{sys}{database}{name};
					my $say_server    = $anvil->data->{database}{$this_uuid}{host}.":".$anvil->data->{database}{$this_uuid}{port}." -> ".$database_name;
					$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0193", variables => { server => $say_server }});

					$anvil->Database->read({set => $anvil->data->{cache}{database_handle}{$this_uuid}});
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 'anvil->Database->read' => $anvil->Database->read }});
					last;
				}
			}

			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				uuid                       => $uuid,
				"sys::database::read_uuid" => $anvil->data->{sys}{database}{read_uuid},
			}});
			if ($uuid eq $anvil->data->{sys}{database}{read_uuid})
			{
				# We were reading from this DB, switch.
				foreach my $this_uuid (keys %{$anvil->data->{cache}{database_handle}})
				{
					# We don't test this connection because, if it's down, we'll know 
					# when it is tested.
					my $database_name = defined $anvil->data->{database}{$this_uuid}{name} ? $anvil->data->{database}{$this_uuid}{name} : $anvil->data->{sys}{database}{name};
					my $say_server    = $anvil->data->{database}{$this_uuid}{host}.":".$anvil->data->{database}{$this_uuid}{port}." -> ".$database_name;
					$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0194", variables => { server => $say_server }});

					$anvil->data->{sys}{database}{read_uuid} = $this_uuid;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::read_uuid" => $anvil->data->{sys}{database}{read_uuid} }});
					last;
				}
			}
			
		}
		else
		{
			# We're in trouble if we don't reconnect...
			$anvil->Database->read({set => "delete"});
			$anvil->data->{sys}{database}{read_uuid} = "";
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
				'anvil->Database->read'    => $anvil->Database->read, 
				"sys::database::read_uuid" => $anvil->data->{sys}{database}{read_uuid},
			}});
			
		}
		
		# Delete the old handle and then try to reconnect. If the reconnect succeeds, and this is the
		# local database, this database will be re-selected as default for reads.
		delete $anvil->data->{cache}{database_handle}{$uuid};
		
		my $delay = 5;
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0195", variables => { 
			delay  => $delay,
			server => $say_server,
		}});
		sleep $delay;
		$anvil->Database->connect({debug => $debug, db_uuid => $uuid});
		
		# If we're down to '0' databases, error out.
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { "sys::database::connections" => $anvil->data->{sys}{database}{connections} }});
		if (not $anvil->data->{sys}{database}{connections})
		{
			# No connections are left, die.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0196"});
			$anvil->nice_exit({code => 1});
			
			# In case we're still alive, die.
			die $THIS_FILE." ".__LINE__."; exiting on DB connection error.\n";
		}
	}
	
	# Success!
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0088"});
	
	return(0);
}