HQ MongoDB check collection size

https://github.com/jamespharaoh/hq-mongodb-check-collection-size

This project provides a script to check that the size of your MongoDB collections doesn't exceed various types of limits.

It is designed to be run either as a nagios or icinga plugin, or as a standalone utility from the command line.

For most use cases, simply install the ruby gem:

gem install hq-mongodb-check-collection-size

You can also install the gem as part of a bundle and run it using the "bundle exec" command.

mkdir my-bundle
cd my-bundle
echo 'source "https://rubygems.org"' >> Gemfile
echo 'gem "hq-mongodb-check-collection-size"' >> Gemfile
bundle install --path gems

If you want to develop the script, clone the repository from github and use bundler to satisfy dependencies:

git clone git://github.com/jamespharaoh/hq-mongodb-check-collection-size.git
cd hq-mongodb-check-collection-size
bundle install --path gems

If the gem is installed correctly, you should be able to run the command with the following name:

hq-mongodb-check-collection-size (options...)

If it was installed via bundler, then you will want to use bundler to invoke the command correctly:

bundle exec hq-mongodb-check-collection-size (options...)

You will also need to provide various options for the script to work correctly.

--verbose
--breakdown
--threads NUM

If --verbose is specified, then a detailed output is generated, showing which collections are over which limit. This should almost always be specified when running manually but would not be specified when used as a nagios or icinga plugin.

The --breakdown option causes a separate line to be output for the data without any indexes, and each index in turn, in addition to the combined line which is normally shown.

The --threads option controls the number of worker threads the script uses. These are used to reduce the total runtime if the many database requests the script makes experience high latency. The default is 20 threads.

--hostname HOSTNAME
--port PORT

Specify the hostname and port of the MongoDB server to connect to. The default is to connect to port 27017 at localhost.

--total-warning SIZE
--total-critical SIZE

Produce a warning or critical error if any collection has a total data size which exceeds either of these values.

--unsharded-warning SIZE
--unsharded-critical SIZE

Same as above, except this only checks collections which are not sharded.

--efficiency-warning PERCENT
--efficiency-critical PERCENT
--efficiency-size SIZE

This compares the data size of the collection to the total storage size allocated to it.

100% represents a collection which fits exactly in the storage space allocated. 50% represents a collecion which takes up half the space and 0% represents a collection with no data in it.

Any collections with a storage size less than --efficiency-size will not be checked.

The script will produce output in the something like the following format:

events 809 megabytes 74% unsharded warning
  data 676 megabytes 71%
  _id_ 92.6 megabytes 85%
  timestamp_1 40.5 megabytes 94%

From the first line we can see the following information:

• This section is about a collection named "events".
• The total storage size for the collection is 809 megabytes. This includes the data and all indexes.
• The storage efficiency is 74%. This refers to the size of the data and indexes divided by the total storage size.
• This collection is unsharded.
• This collection meets the criteria to emit a warning, but not a critical error.

The subsequent three lines provide a breakdown of the same collection but looking separately at the data itself, and at the two indexes which exist.