Sed quis custodiet ipsos custodes? (Monit!)

As companies rely more and more on a Nagios server (or Cacti, SEC, Splunk, etc) the question becomes, “What monitors the monitoring server?” Two popular ways are to just build another Nagios server or use the check_nagios plugin.

When that’s not feasible, I just quickly Monit. As you can see from these examples, babysitting Nagios and Cacti dependencies (e.g. httpd, sshd, etc), alerting when there is a problem, and event handling can be extremely easy. If you would like to make absolute sure that you’re running Monit on your system, you can control it via init in order to have init automatically spawn another daemon.

e.g.
/etc/inittab:

# Run monit in standard run-levels

mo:2345:respawn:/usr/local/bin/monit -Ic /etc/monitrc

After you have modified init’s configuration file, you can run the following command to re-examine /etc/inittab and start monit:

telinit qFor systems without telinit:

kill -1 1