Monitor NDB memory usage with Nagios

We are planning to put online a MySQL NDB Cluster soon (more on this in another post), and one thing you have to do before putting anything in production is to monitor it for problems. In the case of a NDB cluster, you should care about monitoring your limited resources – basically because is a in-memory database – and be alerted when your developers are filling up the dedicated tablespace.

You can do this in two ways: performing a SELECT on the ndbinfo database through the MySQL interface to NDB or parsing the ndb_mgm output. I prefer the latter because maybe I’m using another frontend to the data (native NDB API, memcached etc) and I don’t want to maintain a MySQL server frontend just to check how much space I still have free.

So, you can use this script on GitHub

https://github.com/vide/nagios-ndb/blob/master/check_ndb_usage.sh

to parse its output and know if your tablesapce is OK, warning or critical. Feel free to post any comment, fork it and send patches! :)