Monit is a opensource monitoring tool on Unix system. The simplest use case would be restarting your service if there is failure.

On Ubuntu, simply run apt-get to install Monit.

sudo apt-get install monit

The Monit folder is at /etc/monit. Before you can read anything from Monit, create the /etc/monit/conf.d/monit.conf in order to setup the Monit web interface.

set httpd port 2812 and
  use address localhost
  allow localhost

Restart the Monit.

/etc/init.d/monit restart

Verify if it is working by running monit status.

root@eureka:/etc/monit/conf.d# monit status
The Monit daemon 5.3.2 uptime: 3m 

System 'system_www.eureka.com'
  status                            Running
  monitoring status                 Monitored
  load average                      [0.00] [0.01] [0.05]
  cpu                               0.0%us 0.0%sy 0.0%wa
  memory usage                      173788 kB [28.7%]
  swap usage                        128344 kB [12.2%]
  data collected                    Sun, 29 Jun 2014 14:52:32

You can also access the Monit web portal by opening http://localhost:2812/ in your browser.

Done =)

Reference:

• MONIT
• Monit – Documentation
• DigitalOcean – How To Install and Configure Monit