Setting monit on your Ubuntu

Monit will watch around the clock in your server and can do the following capabilities :

* Monitoring the running server and have the ability to stop , start and restart
* Send email alerts
* Have the ability to monitor the service depends on the cpu,RAM disk, cut-off values


Install::
/home/ubuntu# apt-get install monit
:/etc/monit/conf.d# /etc/init.d/monit restart
 * Restarting daemon monitor monit     

/etc/monit/conf.d# service monit status
 * monit is running


Monit configuration file :: /etc/monit/monitrc

/etc/monit/conf.d# monit status
monit: error connecting to the monit daemon
You will found this error

Actually Monit has an embedded web server which can be used to view status of
services monitored and manage services from a web interface. So we need to enable apache interface in monit configuration file in order to fix this error.

open /etc/monit/monitrc and add the following lines under enable web server.

set httpd port 2812 and
use address localhost
allow localhost
allow admin:monit

/etc/monit/conf.d# /etc/init.d/monit restart
 * Restarting daemon monitor monit

/etc/monit/conf.d# netstat -lpn | grep 2812
tcp        0      0 127.0.0.1:2812          0.0.0.0:*               LISTEN      418/monit


root@ip-172-31-56-245:/etc/monit/conf.d# monit summary
The Monit daemon 5.6 uptime: 0m

Process 'mysqld'                    Running
System 'ip-172-31-56-245.ec2.internal' Running

Check out if mysql service is down on the server.

 /etc/monit/conf.d# service mysql status
mysql stop/waiting

root@ip-172-31-56-245:/etc/monit/conf.d# monit summary
The Monit daemon 5.6 uptime: 1m

Process 'mysqld'                    Does not exist
System 'ip-172-31-56-245.ec2.internal' Running

After 5 minute monit will automatically restart mysql service.

root@ip-172-31-56-245:/etc/monit/conf.d# monit summary
The Monit daemon 5.6 uptime: 5m

Process 'mysqld'                    Running
System 'ip-172-31-56-245.ec2.internal' Running