Munin contributed plugins

#!/usr/bin/perl -w

# Plugin for monitor postgres connections without DBI.

#

# Licenced under GPL v2.

#

# Usage:

#

#       Symlink into /etc/munin/plugins/ and add the monitored

#       database to the filename. e.g.:

#

#       ln -s /usr/share/munin/plugins/pg__connections \

#         /etc/munin/plugins/pg_<databasename>_connections

#       This should, however, be given through autoconf and suggest.

#

#       If required, give username, password and/or Postgresql server

#       host through environment variables.

#

#       You must also activate Postgresql statistics. See

#       http://www.postgresql.org/docs/7.4/interactive/monitoring-stats.html

#       for how to enable this. Specifically, the following lines must

#       exist in your postgresql.conf:

#

#           stats_start_collector = true

#           stats_block_level = true

#

#

# Parameters:

#

#       config   (required)

#

# Config variables:

#

#       dbhost     - Which database server to use. Defaults to

#                    'localhost'.

#       dbname     - Which database to use. Defaults to template1

#       dbuser     - A Postgresql user account with read permission to

#                    the given database. Defaults to

#                    'postgres'. Anyway, Munin must be told which user

#                    this plugin should be run as.

#       dbpass     - The corresponding password, if

#                    applicable. Default to undef. Remember that

#                    pg_hba.conf must be configured accordingly.

#

# Magic markers

#%# family=auto

#%# capabilities=autoconf

use strict;

my $psql   = $ENV{'psql'} || '/usr/bin/psql';

my $dbhost = $ENV{'dbhost'} || '127.0.0.1';

my $dbname = $ENV{'dbname'} || 'template1';

my $dbuser = $ENV{'dbuser'} || 'munin';

#my $dbuserx = $ENV{'dbuserx'} || '';

my $dbport = $ENV{'dbport'} || '5432';

my $dbpass = $ENV{'dbpass'} || 'munin';

my $COMMAND = "PGPASSWORD='$dbpass' '$psql' '$dbname' -h '$dbhost' -U '$dbuser' -p '$dbport' -A -F, -t ";

if (exists $ARGV[0]) {

    if ($ARGV[0] eq "config") {

		my $sqlCommand = "$COMMAND -c 'SHOW max_connections;'";

		my ($max_connections) = `$sqlCommand`;

		my $warning = int ($max_connections * 0.7);

		my $critical = int ($max_connections * 0.8);

		print "graph_title PostgresSQL active connections\n";

		print "graph_args -l 0 --base 1000\n";

		print "graph_vlabel Connections\n";

		print "graph_category db\n";

		print "graph_info Shows active Postgresql connections from $dbname\n";

		$sqlCommand = "$COMMAND -c 'select datname, count(*) from pg_stat_activity group by datname;'";

		open(SERVICE, "$sqlCommand |")

			or die("Could not execute '$sqlCommand': $!");

		my $setarea = "yes";

		while (<SERVICE>) {

			my ($datname, $curr_conn) = (m/(\w+).*?(\d+(?:\.\d+)?)/);

			print "$datname.label $datname active connections\n";

			print "$datname.info $datname active connections\n";

			print "$datname.type GAUGE\n";

			if ($setarea eq "yes") {

        		print "$datname.draw AREA\n";

				$setarea="";

        	} else {

				print "$datname.draw STACK\n";

			}

		}

		print "max_connections.label Max. connections\n";

		print "max_connections.info Max. connections\n";

		print "max_connections.type GAUGE\n";

		print "warning $warning\n";

		print "critical $critical\n";

		exit 0;

    }

}

# select datname, count(*) from pg_stat_activity group by datname

my $sqlCommand = "$COMMAND -c 'SHOW max_connections;'";

my ($max_connections) = `$sqlCommand`;

$sqlCommand = "$COMMAND -c 'select datname, count(*) from pg_stat_activity group by datname;'";

open(SERVICE, "$sqlCommand |")

	or die("Could not execute '$sqlCommand': $!");

while (<SERVICE>) {

	my ($datname, $curr_conn) = (m/(\w+).*?(\d+(?:\.\d+)?)/);

	print "$datname.value $curr_conn\n";

}

print "max_connections.value $max_connections\n";