Monit is a small Open Source utility for managing and monitoring Unix systems. Monit conducts automatic maintenance and repair and can execute meaningful causal actions in error situations.

Design philosophy

It is important for a system monitoring tool to just work - all the time, and you should be able to trust it to do so. A system monitoring tool needs to be non-intrusive and you should be able to forget about it once it's installed. That is, until sshd dies on your hosted server. When this happens, it is good to know that you have installed this extra layer of security and protection, just wait a few seconds and Monit will restart the sshd daemon. It is also helpful to get an email alert before the server disks are full or if your http server suddenly is under a DDoS attack.

Monit is designed as an autonomous system and does not depend on plugins nor any special libraries to run. Instead it works right out of the box and can utilize existing infrastructure already on your system. For instance, Monit will easily integrate with init, upstart or systemd and can use existing run-level scripts to manage services.

Monit compiles and run on most flavors of Unix. It is a small program and weights in at around 500kB (stripped). There is support for compiling with glibc replacements such as uClibc if you need it to be even smaller.