Merge pull request #4416 from alphagov/add_filehandles_collectd

Add filehandles to collectd

modules/collectd/files/usr/lib/collectd/file_handles.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+# Author: Phil Dufault (phil@dufault.info)
+# https://raw.githubusercontent.com/pdufault/collectd-exec-file_handles/master/file_handles.sh 
+# Commit 76e100799ae4d1cc231d0d343bd930f28d8d90c5
+# Date: April 2nd, 2014
+# Use: collectd exec script to collect system file handle metrics
+
+HOSTNAME="${COLLECTD_HOSTNAME:-`hostname -f`}"
+INTERVAL="${COLLECTD_INTERVAL:-10}"
+
+while sleep "$INTERVAL"; do
+
+  # Historically, the three values in file-nr denoted the number of
+  # * allocated file handles
+  # * the number of allocated but unused file handles
+  # * the maximum number of file handles.
+  # Linux 2.6 always reports 0 as the number of free file handles -- this is not an error, it just means that the number of allocated file handles exactly matches the number of used file handles.
+
+  # Grab the metrics
+  file_nr=($(cat /proc/sys/fs/file-nr))
+  allocated=${file_nr[0]}
+  allunused=${file_nr[1]}
+  max=${file_nr[2]}
+
+  # Output time
+  echo "PUTVAL $HOSTNAME/system-file_handles/gauge-file_handles_used interval=$INTERVAL N:$allocated"
+  echo "PUTVAL $HOSTNAME/system-file_handles/gauge-file_handles_allocatedunused interval=$INTERVAL N:$allunused"
+  echo "PUTVAL $HOSTNAME/system-file_handles/gauge-file_handles_max interval=$INTERVAL N:$max"
+
+  # putval format
+  #            <instance-id>/<plugin>-<plugin_instance>/<type>-<type_instance>
+
+done

modules/collectd/manifests/config.pp

@@ -36,6 +36,7 @@
     source => 'puppet:///modules/collectd/etc/collectd/conf.d/network.conf.client',
   }
 
+  include ::collectd::plugin::file_handles
   # Always collect basic processlist info.
   include ::collectd::plugin::processes
   include ::collectd::plugin::tcpconns

modules/collectd/manifests/plugin/file_handles.pp

@@ -0,0 +1,22 @@
+# == Class: collectd::plugin::file_handles
+#
+# Monitors the number of file handles in use on a system
+#
+class collectd::plugin::file_handles(
+) {
+
+  @file { '/usr/lib/collectd/file_handles.sh':
+    ensure  => 'present',
+    mode    => '0755',
+    owner   => 'root',
+    group   => 'root',
+    content => file('collectd/usr/lib/collectd/file_handles.sh'),
+    tag     => 'collectd::plugin',
+  }
+
+  @collectd::plugin { 'file_handles':
+    content => template('collectd/etc/collectd/conf.d/file_handles.conf.erb'),
+    require => File['/usr/lib/collectd/file_handles.sh'],
+  }
+
+}

modules/collectd/templates/etc/collectd/conf.d/file_handles.conf.erb

@@ -0,0 +1,5 @@
+LoadPlugin exec
+
+<Plugin exec>
+  Exec nobody "/usr/lib/collectd/file_handles.sh"
+</Plugin>