What is Monit?
Monit is an Open Source utility that manages and monitors servers (Unix systems) that conduct automatic maintenance, repair and execute meaningful causal actions in server errors or situations. It became popular because it supports Ruby on Rails when there was a need for a tool to manage the identical Mongrel web server processes. Twitter and Scribd are just two examples.
Monit is Proactive
It automatically does an action when a situation or error occurs. For an example if a service like php5-fpm stops running or the servers load too many resources, it can stop or restart specific services and send an alert message via email or any possible medium. If a DoS attacks a server, Monit would be one of the best solutions to address a situation such as restarting the apache or nginx services. By being proactive, it can also oversee the process characteristics such as memory or cpu cycles that the process is using.
Monit for Processes
Monit monitors daemon processes or applications running in localhost or even in remote servers. It is very useful in monitoring startup processes that are usually in /etc/init/ or /etc/init.d/ folders that run during boot time of Unix systems. Those processes may or may not include sshd, apache, nginx, and mysql.
Monit for Files and Directory Monitoring
It is also useful in scanning files and directories on local hosts and Unix servers. It observes the changes of files such as timestamps, checksum, or size. The md5 or sha1 checksum can also be monitored for additional security reasons. If the changes were made on md5 and sha1, an action is made and an alert will be sent to the system administrator.
Monit in Cloud and Web Hosts
The connections from server to server are well-reported in Monit. The server could either be in localhost or in remote hosts. The mMnit supports sockets such as TCP, UDP and Unix Domain Sockets. On a protocol level, tests can be done by testing http, smtp, etc. Monit can also be configured to test the network by sending data and get the response from the server.
Monit as Programs and Scripts Checker
Programs and scripts are testable just like in cron however you can add an exit value to a program and perform a specific action while sending an alert to the system administrator if the exit value returns an error. This expands Monit’s ability to perform checks that are dependent on your created script.
Monit for System Monitoring
Lastly, it is also very important because it monitors resources on Unix systems. It can monitor CPU usage and processes, Memory usage and processes, Swap Usage, Load Average and the Post response time.
Why do we need Monit?
Server management is absolutely essential in any web development company. Overseeing and managing your company’s web servers with Monit will give you real-time reports on the status of the servers and you can give your clients the assurance of continued reliable and on-time automated services even if an error occurs.
