Monit is a utility for managing and monitoring, processes, files, directories and filesystems on a UNIX system. Monit conducts automatic maintenance and repair and can execute meaningful causal actions in error situations.

What Monit can do

Monit can start a process if it does not run, restart a process if it does not respond and stop a process if it uses too much resources. You can use Monit to monitor files, directories and filesystems for changes, such as timestamp changes, checksum changes or size changes. You can also monitor remote hosts; Monit can ping a remote host and can check TCP/IP port connections and server protocols. Monit is controlled via an easy to use control file based on a free-format, token-oriented syntax. Monit logs to syslog or to its own log file and notifies you about error conditions and recovery status via customizable alert.

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 need to be non-intrusive and you should be able to forget about it once it's installed. That is, until sshd dies on your co-located server, 50 miles away. 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 alert mail before the server disks are full or if your http server suddenly is slashdotted.

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 and can use existing runlevel rc-scripts to manage services. There are also flexibility for those special cases when you need a certain setup for a service.

Monit compiles and run on most flavors of UNIX. It is a small program and weights in at just over 300kB. There is support for compiling with glibc replacements such as uClibc if you need it to be even smaller.

Check server status with a Web Browser

Monit provides a built-in HTTP(S) interface and you can use a browser to access the Monit server. Check out the screen shoots page for an overview of available pages.

Getting started

Read the Monit presentation, available in PDF. Browse the Monit manual online.

Open source

Monit is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License. Monit is an open-source project consisting of non-paid volunteers who contribute work and code to the project in their own free time. The project consists of a core team of developers and many contributors from around the world. There is also a large and active community of users who discuss usage of Monit, answer questions and share tips and hacks on the Monit mailing lists.

Mailing lists

We have setup a mailing list which contain many individuals who will help answer detailed requests for help. You may also search the archive for answers. Join the Monit general list if you have questions or if you simply want to discuss Monit and submit ideas, suggestions, and comments. New releases will also be announced to this list. Join the Monit developer list if you want to discuss design issues, code changes, additions, etc.

If you only want to get a notification when new releases of Monit are available, please join the very low traffic Monit announce mailing list. This list is used to announce major releases and other important information about the Monit project. Messages are posted only by the Monit project; there is no discussion.

Support Monit

Any donation is greatly appreciated and will help us continue to develop and support Monit. When you donate money or support us by other means you will be mentioned under the sponsors section on the Monit web site (unless you want to be anonymous).

Another way to support Monit is to try out M/Monit and if you like M/Monit, buy a license.

Acknowledgments

Thanks to the Free Software Foundation (FSF) for hosting the CVS repository and the mailing lists.