bin/metric-postgres-connections.rb
#! /usr/bin/env ruby
# frozen_string_literal: false
#
# metric-postgres-connections
#
# DESCRIPTION:
#
# This plugin collects postgres connection metrics
#
# OUTPUT:
# metric data
#
# PLATFORMS:
# Linux
#
# DEPENDENCIES:
# gem: sensu-plugin
# gem: pg
#
# USAGE:
# ./metric-postgres-connections.rb -u db_user -p db_pass -h db_host -d db
#
# NOTES:
#
# LICENSE:
# Copyright (c) 2012 Kwarter, Inc <platforms@kwarter.com>
# Author Gilles Devaux <gilles.devaux@gmail.com>
# Released under the same terms as Sensu (the MIT license); see LICENSE
# for details.
#
require 'sensu-plugins-postgres/pgpass'
require 'sensu-plugin/metric/cli'
require 'pg'
require 'socket'
class PostgresStatsDBMetrics < Sensu::Plugin::Metric::CLI::Graphite
option :pgpass,
description: 'Pgpass file',
short: '-f FILE',
long: '--pgpass',
default: "#{ENV['HOME']}/.pgpass"
option :user,
description: 'Postgres User',
short: '-u USER',
long: '--user USER'
option :password,
description: 'Postgres Password',
short: '-p PASS',
long: '--password PASS'
option :hostname,
description: 'Hostname to login to',
short: '-h HOST',
long: '--hostname HOST'
option :port,
description: 'Database port',
short: '-P PORT',
long: '--port PORT'
option :database,
description: 'Database name',
short: '-d DB',
long: '--db DB'
option :scheme,
description: 'Metric naming scheme, text to prepend to $queue_name.$metric',
long: '--scheme SCHEME',
default: "#{Socket.gethostname}.postgresql"
option :timeout,
description: 'Connection timeout (seconds)',
short: '-T TIMEOUT',
long: '--timeout TIMEOUT',
default: nil
include Pgpass
def run
timestamp = Time.now.to_i
pgpass
con = PG.connect(host: config[:hostname],
dbname: config[:database],
user: config[:user],
password: config[:password],
port: config[:port],
connect_timeout: config[:timeout])
request = [
"select case when count(*) = 1 then 'waiting' else",
"'case when wait_event_type is null then false else true end' end as wait_col",
'from information_schema.columns',
"where table_name = 'pg_stat_activity' and table_schema = 'pg_catalog'",
"and column_name = 'waiting'"
]
wait_col = con.exec(request.join(' ')).first['wait_col']
request = [
"select count(*), #{wait_col} as waiting from pg_stat_activity",
"where datname = '#{config[:database]}' group by #{wait_col}"
]
metrics = {
active: 0,
waiting: 0,
total: 0
}
con.exec(request.join(' ')) do |result|
result.each do |row|
if row['waiting'] == 't'
metrics[:waiting] = row['count']
elsif row['waiting'] == 'f'
metrics[:active] = row['count']
end
end
end
metrics[:total] = (metrics[:waiting].to_i + metrics[:active].to_i)
metrics.each do |metric, value|
output "#{config[:scheme]}.connections.#{config[:database]}.#{metric}", value, timestamp
end
ok
end
end