#!/usr/bin/perl -w

# re-write of python version of pgbouncer stats
# data from stats, pools (client, server)

use strict;
use Munin::Plugin;
use DBD::Pg;

# check that multigraph is available
need_multigraph();
# get the script name
my $plugin_name = $Munin::Plugin::me;
# set the DB connection vars
my $db_user = $ENV{'pgbouncer_user'}  || 'postgres';
my $db_port = $ENV{'pgbouncer_port'}  || '6432';
my $db_host = $ENV{'pgbouncer_host'}  || 'localhost';
my $db_pass = $ENV{'pgbouncer_pass'}  || '';
my $db_pool = $ENV{'pgbouncer_pool'}  || '';
my $db_name = 'pgbouncer';
my @data = ();
# get the DB (pool) name we want to fetch
$plugin_name =~ /pgbouncer_(.*)$/;
my $plugin_suffix = $1;
#if pool name is specified explicitly in config file
#use plugin name together with pool name in graph title:
my $pool_name = ($db_pool) ? $db_pool : $plugin_suffix;
my $plugin_title = ($db_pool) ? $plugin_suffix." ".$pool_name : $pool_name;

# bail if no name
if (!$pool_name)
{
	print "Cannot get pool name\n";
	exit 1;
}

# command line arguments for autconf and config
if (defined($ARGV[0]))
{
	# autoconf, nothing to do
	if ($ARGV[0] eq 'autoconf')
	{
		my $dbh = DBI->connect("DBI:Pg:dbname=$db_name;host=$db_host;port=$db_port", $db_user, $db_pass);
		if (!$dbh)
		{
			print "no\n";
		}
		else
		{
			print "yes\n";
		}
		$dbh->disconnect();
		exit 0;
	}

	if ($ARGV[0] eq 'config')
	{
		# create the basic RRD
		# stats: average connections

		print "multigraph ".$plugin_name."_stats_avg_req\n";
		print "graph_title PgBouncer $plugin_title average connections\n";
		print "graph_args --base 1000\n"; # numbers not bytes
		print "graph_vlabel Average connections\n";
		print "graph_scale no\n"; # so we do not print "micro, milli, kilo, etc"
    		print "graph_category db\n";
		print $pool_name."_avg_req.type GAUGE\n";
		print $pool_name."_avg_req.label Avg Req\n";
		print $pool_name."_avg_req.min 0\n";
		print $pool_name."_avg_req.draw LINE2\n";
		# stats: average time for query
		print "multigraph ".$plugin_name."_stats_avg_query\n";
		print "graph_title PgBouncer $plugin_title average query time\n";
		print "graph_args --base 1000\n"; # numbers not bytes
		print "graph_vlabel Average time per query (microseconds)\n";
    		print "graph_category db\n";
		print $pool_name."_avg_query.type GAUGE\n";
		print $pool_name."_avg_query.label Avg Time\n";
		print $pool_name."_avg_query.min 0\n";
		print $pool_name."_avg_query.draw LINE2\n";
		# stats: in/out bytes
		print "multigraph ".$plugin_name."_stats_bytesinout\n";
		print "graph_title PgBouncer $plugin_title average bytes received/sent\n";
		print "graph_args --base 1024\n"; # numbers in bytes
		print "graph_vlabel Average bytes received (-)/sent (+)\n";
    		print "graph_category db\n";
		# bytes received
		print $pool_name."_avg_recv.type GAUGE\n";
		print $pool_name."_avg_recv.label Avg received\n";
		print $pool_name."_avg_recv.min 0\n";
		print $pool_name."_avg_recv.draw LINE1\n";
		print $pool_name."_avg_recv.graph no\n";
		# bytes sent
		print $pool_name."_avg_sent.type GAUGE\n";
		print $pool_name."_avg_sent.label Avg rcvd/sent\n";
		print $pool_name."_avg_sent.min 0\n";
		print $pool_name."_avg_sent.draw LINE1\n";
		print $pool_name."_avg_sent.negative ".$pool_name."_avg_recv\n";
		# pools: server (sv_)
		print "multigraph ".$plugin_name."_pools_server\n";
		print "graph_title PgBouncer $plugin_title servers\n";
		print "graph_category db\n";
		print "graph_args --base 1000\n"; # numbers not bytes
		print "graph_vlabel Server connections\n";
		print "graph_scale no\n";
		# active connections
		print $pool_name."_server_active.label active\n";
		print $pool_name."_server_active.min 0\n";
		print $pool_name."_server_active.type GAUGE\n";
		print $pool_name."_server_active.draw AREA\n";
		# idle connections
		print $pool_name."_server_idle.label idle\n";
		print $pool_name."_server_idle.min 0\n";
		print $pool_name."_server_idle.type GAUGE\n";
		print $pool_name."_server_idle.draw STACK\n";
		# used connections
		print $pool_name."_server_used.label used\n";
		print $pool_name."_server_used.min 0\n";
		print $pool_name."_server_used.type GAUGE\n";
		print $pool_name."_server_used.draw STACK\n";
		# tested connections
		print $pool_name."_server_tested.label tested\n";
		print $pool_name."_server_tested.min 0\n";
		print $pool_name."_server_tested.type GAUGE\n";
		print $pool_name."_server_tested.draw STACK\n";
		# logged in connections
		print $pool_name."_server_login.label login\n";
		print $pool_name."_server_login.min 0\n";
		print $pool_name."_server_login.type GAUGE\n";
		print $pool_name."_server_login.draw STACK\n";
		# pools: client (cl_)
		print "multigraph ".$plugin_name."_pools_client\n";
		print "graph_title PgBouncer $plugin_title clients\n";
		print "graph_category db\n";
		print "graph_args --base 1000\n"; # numbers not bytes
		print "graph_vlabel Client connections\n";
		print "graph_scale no\n";
		# active client connections
		print $pool_name."_client_active.label active\n";
		print $pool_name."_client_active.min 0\n";
		print $pool_name."_client_active.type GAUGE\n";
		print $pool_name."_client_active.draw AREA\n";
		# waiting client connections
		print $pool_name."_client_waiting.label waiting\n";
		print $pool_name."_client_waiting.min 0\n";
		print $pool_name."_client_waiting.type GAUGE\n";
		print $pool_name."_client_waiting.draw STACK\n";
		# pools: maxwait (longest waiting connection, should be 0)
		print "multigraph ".$plugin_name."_pools_maxwait\n";
		print "graph_title PgBouncer $plugin_title maximum waiting time\n";
		print "graph_args --base 1000\n"; # numbers not bytes
		print "graph_vlabel Maximum wait time (seconds)\n";
    		print "graph_category db\n";
		print $pool_name."_maxwait.type GAUGE\n";
		print $pool_name."_maxwait.label Wait Time\n";
		print $pool_name."_maxwait.min 0\n";
		print $pool_name."_maxwait.draw LINE2\n";
		print $pool_name."_maxwait.warning 1\n"; # warn if not 0
		print $pool_name."_maxwait.critical 10\n"; # go critical if 10 seconds waiting
		# END graph
		exit 0;
	}
}

# connect to data
my $dbh = DBI->connect("DBI:Pg:dbname=$db_name;host=$db_host;port=$db_port", $db_user, $db_pass)
	 or die ("Cannot connect to database");
# go through each set and get the data
foreach my $get ('pools', 'stats')
{
	# prep and execute the show query
	my $pre = $dbh->prepare("SHOW $get")
		or die ("Cannot prepare query");
	$pre->execute()
		or die ("Cannot execute statement");
	while (@data = $pre->fetchrow)
	{
		# first defines the pool
		if ($data[0] eq $pool_name)
		{
			# print values for the stats: average request, average query time, bytes in/out
			if ($get eq 'stats')
			{
				print "multigraph ".$plugin_name."_".$get."_avg_req\n";
				print $pool_name."_avg_req.value ".$data[5]."\n";
				print "multigraph ".$plugin_name."_".$get."_avg_query\n";
				print $pool_name."_avg_query.value ".$data[8]."\n";
				print "multigraph ".$plugin_name."_".$get."_bytesinout\n";
				print $pool_name."_avg_recv.value ".$data[6]."\n";
				print $pool_name."_avg_sent.value ".$data[7]."\n";
			}
			# print data for the pools: server, client
			if ($get eq 'pools')
			{
				print "multigraph ".$plugin_name."_".$get."_server\n";
				print $pool_name."_server_active.value ".$data[4]."\n";
				print $pool_name."_server_idle.value ".$data[5]."\n";
				print $pool_name."_server_used.value ".$data[6]."\n";
				print $pool_name."_server_tested.value ".$data[7]."\n";
				print $pool_name."_server_login.value ".$data[8]."\n";
				print "multigraph ".$plugin_name."_".$get."_client\n";
				print $pool_name."_client_active.value ".$data[2]."\n";
				print $pool_name."_client_waiting.value ".$data[3]."\n";
				print "multigraph ".$plugin_name."_".$get."_maxwait\n";
				print $pool_name."_maxwait.value ".$data[9]."\n";
			}
		}
	}
}
# close connection
$dbh->disconnect();

exit 0;

__END__

=head1 NAME

pgbouncer_ is a plugin to get the pool and stat values for a single pgbouncer pool name

=head1 APPLICATION

perl and DBD::Pg is required, and pgbouncer must been installed with a correct setup access for a stat account

=head1 CONFIGURATION

the plugin that will be run needs to have the pool name after the plugin base name.
alternatively, pool name can be specified in config file as env.pgbouncer_pool option, separating plugin name from pool name.

=head2 plugin configuration

eg: pgbouncer_foo will run for the pool named foo.

see SHOW POOLS database list for the pool name

=head2 munin plugin config file

in the plugin config file under the [pgbouncer] name the access information ca be set.

eg:
  [pgbouncer*]
    env.pgbouncer_pass barfoo

more extended would be:
  [pgbouncer*]
    env.pgbouncer_pass barfoo
    env.pgbouncer_user bar
    env.pgbouncer_port 6542
    env.pgbouncer_host localhost

another example, where different pgbouncers (and so munin plugins) connecting to same db:
   [pgbouncer_weblogin]
     env.pgbouncer_pass barfoo
     env.pgbouncer_user bar
     env.pgbouncer_port 6542
     env.pgbouncer_host localhost
     env.pgbouncer_pool dbname

   [pgbouncer_webmain]
     env.pgbouncer_pass barfoo
     env.pgbouncer_user bar
     env.pgbouncer_port 6543
     env.pgbouncer_host localhost
     env.pgbouncer_pool dbname

The database name is always pgbouncer

=head1 OUTPUT

The plugin will output 5 graphs in the group pgbouncer

=head2 Average bytes received/sent

This graph will show the average bytes sent and received by the pgbouncer for this pool

=head2 Average connections

This graph will show the average amount of connections to the pgbouncer for this pool

=head2 Average query time

This graph shows the average query time as processed by the pgbouncer for this pool in microseconds. The data will be shorted by standard SI. eg, m = milli, k = kilo.

So 4.61K is 4610 milliseconds

=head2 Client connections

This graph shows the active and waiting client connections to pgbouncer for this pool

=head2 Server connections

This graph shows the server connections to pgbouncer for this pool. The following data sets are shown: active, idle, used, tested, login

=head2 Max wait

how long the oldest client the queue has waited, should be always 0

=head1 ACKNOWLEDGEMENTS

Original idea derived from a simple python script by Dimitri Fontaine

=head1 SEE ALSO

See further info on stats and pools on the pgbouncer homepage:
  http://pgbouncer.projects.postgresql.org/doc/usage.html#_show_commands

=head1 VERSION

1.0

=head1 AUTHOR

Clemens Schwaighofer <gullevek@gullevek.org>

=head1 LICENSE

GPLv2


=cut