Munin contributed plugins

#!/bin/bash

#

# Plugin to monitor PostgreSQL Backends

#

# Author:

#    Guilherme Augusto da Rocha Silva <gars.dba@gmail.com>

#

# Created:

#    5th of november 2007

#

# Usage:

#    Place in /etc/munin/plugins/ (or link it there using ln -s)

#

# Parameters:

#    config   (required)

#

# General info:

#    Require permission for database access and read (no writes are processed).

#    Recomended user is PostgreSQL database owner (default: postgres).

#

# Log info:

# 2007/11/30 - Review on comments

#

dbserver='localhost'

dbuser='postgres'

if [ "$1" = "config" ]; then

   maximum=$(psql -h ${dbserver} -U ${dbuser} -tc "SHOW max_connections;" | bc)

   reserved=$(psql -h ${dbserver} -U ${dbuser} -tc "SHOW superuser_reserved_connections;" | bc)

   warning=$(((maximum-reserved)*70/100))

   critical=$(((maximum-reserved)*90/100))

   echo 'graph_args --base 1000 --lower-limit 0 --upper-limit '${maximum}

   echo 'graph_category Postgresql'

   echo 'graph_info Shows open backends on the PostgreSQL Server.'

   echo 'graph_scale no'

   echo 'graph_title PostgreSQL Active Backends'

   echo 'graph_vlabel Number of active backends'

   echo 'backends.label backends'

   echo 'backends.type GAUGE'

   echo 'backends.min 0'

   echo 'backends.max '${maximum}

   echo 'backends.warning '${warning}

   echo 'backends.critical '${critical}

   echo 'backends.info Number of open sessions.'

   exit 0

fi

echo 'backends.value '$(psql -h ${dbserver} -U ${dbuser} -tc "SELECT SUM(numbackends) FROM pg_stat_database;" | bc)