On Galera, you know that there are a lot of options and things to check to ensure that the nodes are working fine.

Percona made a script for Nagios to manage all essentials parameters and to ensure that Galera Cluster is working fine. In fact, it was able to parse the result of the Galera SHOW STATUS LIKE 'wsrep_%' and look at if it finds a matched string or not.

To install the script, you need to have the Percona repository set correctly and then you can install the package:

> apt-key adv --keyserver keys.gnupg.net --recv-keys 1C4CBDCDCD2EFD2A
> add-apt-repository 'deb http://repo.percona.com/apt wheezy main'
> echo 'Package: *
Pin: release o=Percona Development Team
Pin-Priority: 100' > /etc/apt/preferences.d/00percona.pref
> aptitude update
> aptitude install percona-nagios-plugins

The plugins will be installed under /usr/lib64/nagios/plugins.

First of all, what you generally want to do is to check the cluster size, to be sure all your nodes are here. Let...