The initiator however is not locally, it’s a different (remote) server. So basically the server executes local commands like monit. If the check exceeds it’s given limit, Nagios / Iciniga / check_mk creates an E-Mail and send it to the user /group of users which is / are responsible for this service. The console output is then used for analysis.

In the first moment this sounds like a disadvantage whether it be due to reliability or security, but think about it for a second: What does Nagios, Icinga or check_mk basically do? They ping the destination machine and if this ping is successful it opens up an NRPE or SSH connection and executes the given CPU, Ram, service checks and so on, locally. So basically that means that wherever monit is installed, it checks locally and reports the results via mail. While Nagios, Icinga and check_mk needs a monitoring server which connects in given time periods to the machines it checks, monit doesn’t need this kind of server in order to do these checks.

Monit works differently than Nagios or Icinga. How does monit works? And why not just use Nagios? However, just because the configuration is more simple, that doesn’t mean hat you are limited in the ways you monitor your servers with Monit. Monit is one of these simple monitoring tool. Especially if you are a private person and you want to monitor your vServer, Raspberry Pi or whatever, you may want to use a smaller and easier monitoring solution than those big three. Besides Nagios, Icinga and check_mk there are some other, more slimmer tools to monitor servers.

M monit free