#!/bin/sh

: <<=cut

=head1 NAME

postgresql_transactions - Plugin to monitor PostgreSQL Commits and Rollbacks in Transactions


=head1 USAGE

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

General info:
   Requires permission for database read access (no writes are processed).
   Recommended user is PostgreSQL database owner (default: postgres).


=head1 CONFIGURATION

The following configuration directives may be placed below /etc/munin/plugin-conf.d/ (optional):

   [postgresql_transactions]
   user postgres
   env.dbuser postgres
   env.dbhost localhost


=head1 AUTHOR

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

   Copyright (C) 2007 Guilherme Augusto da Rocha Silva <gars.dba@gmail.com>

=cut

dbhost=${dbhost:-localhost}
dbuser=${dbuser:-postgres}


do_config() {
   echo 'graph_args --base 1000 --lower-limit 0'
   echo 'graph_category db'
   echo 'graph_info Shows summarized commits and rollbacks in transactions on the PostgreSQL Server.'
   echo 'graph_title PostgreSQL Transactions'
   echo 'graph_vlabel Commits and Rollbacks per second'

   echo 'commits.label commits'
   echo 'commits.min 0'
   echo 'commits.type DERIVE'
   echo 'commits.info Number of transaction commits per second.'

   echo 'rollbacks.label rollbacks'
   echo 'rollbacks.min 0'
   echo 'rollbacks.type DERIVE'
   echo 'rollbacks.info Number of transaction rollbacks per second.'
}


do_fetch() {
   psql -h "$dbhost" -U "$dbuser" -tc "SELECT 'commits.value '||SUM(xact_commit)::TEXT||E'\\nrollbacks.value '||SUM(xact_rollback)::TEXT FROM pg_stat_database;" --no-align
}


if [ "$1" = "config" ]; then
   do_config
   if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
else
   do_fetch
fi