Munin and PostgreSQL monitoring

I ran into a little hiccup when trying to configure Munin to monitor PostgreSQL. After linking the ‘postgres_’ plugins and restarting munin-node, no Postgres stats were appearing and I was seeing error messages in the munin-node.log like this:

Service 'postgres_size_ALL' exited with status 1/0
Service 'postgres_locks_ALL' exited with status 1/0
Service 'postgres_cache_ALL' exited with status 1/0

Not very helpful but, it turns out, easy to fix. The Munin Postgres plugins use Perl and the DBD::Pg module to talk to your PostgreSQL database so if either of these are missing, you’ll get these errors.

The solution is to install the DBD::Pg module from CPAN. If you’re using Chef, add the perl cookbook and then run cpan_module 'DBD::Pg in a recipe somewhere.