munin-mongo-collections¶ ↑

This project contains the munin plugin that monitors the number of documents in various collections within a database. The database name is configured in the munin-plugin.conf file.

Dependencies¶ ↑

• Ruby 1.8+

• mongo gem

Installation¶ ↑

I have tested these steps on Centos5 and Ubuntu 10.10

Follow these steps on the same server you’re running your mongo instance on.

NOTE: If running master/slave I’d recommend doing this on just one of the slave nodes. Do not set up this plugin on all the nodes in a replica-set/replica-pair or master/slave config, as they all will report pretty much the same data.

• Verify if you have mongo gem installed

mpandit@mpandit-ubuntu:~$ gem list | grep mongo mongo (1.1.2, 1.1)

• If missing, then install with

gem install mongo

• Grab the plugin

git clone git://github.com/lobster1234/munin-mongo-collections

• Make sure mongo_collections.rb is +x for owner, group and others

  chmod +x mongo_collections.rb

cp mongo_collections.rb /usr/share/munin/plugins/ ln -s /usr/share/munin/plugins/mongo_collections.rb /etc/munin/plugins/mongo_collections.rb

• Now to add the database name to the plugin configuration, do this:

  sudo vi /etc/munin/plugin-conf.d/munin-node
  

• Paste this to the bottom of the file

[mongo*] env.dbname replace_with_your_database_name

• Save, and exit

• Restart the munin node

sudo /etc/init.d/munin-node restart

• Make sure the munin server is listening from this node and you should be good to go!

Test¶ ↑

• You can test this by simply running the plugin on command line (replace mydb with your database name)

  export dbname=mydb 
  cd /etc/munin/plugins
  ./mongo_collections config

• You should see something like this, in this case mydb contains only 1 collection called twitter.

  twitter.label twitter
  twitter.min 0
  twitter.max 3000000
  twitter.draw LINE1
  twitter.type GAUGE
  twitter.info Number of documents in twitter
  graph_title MongoDB Collections in mydb
  graph_args --base 1000
  graph_vlabel documents
  graph_category MongoDB

TODO¶ ↑

• Support discovery of databases on the node and pick up the collections in every db

• Support datbase/collection names whitelisting where only the whitelisted dbs/collections will be scanned

• Support user/password auth

• Remove dependency on running on the same node as the mongo instance.

Enjoy!

@lobster1234 on Twitter pandit(dot)manish(at)gmail(dot)com