Nagios Service and Hosts stats - Graphed in Munin
We’ve been hitting some load issues on one of our monitoring machines recently and while it looks like the munin graph generation is the culprit we also decided to keep an eye on how many services and hosts Nagios was checking.
One of the downsides of having a very automated server deployment system is how easy it is to suddenly find yourself with an extra dozen hosts you no longer really need. While each check is quite small and quick, add up the frequent runs and multiply it by a reasonable number of servers and you can soon hit problems. So as a first step towards keeping an eye on those numbers we now have a munin Nagios hosts plugin and a munin Nagios services plugin that show the total number of hosts and services monitored and the states those resources are in.