Monitoring
Now that you've got your servers up and running, you'll want to monitor their performance and
availability. After all, nobody is going to sign up for a service that is slow and only available some of
the time.
By monitoring the vital signs of your web servers and network, you'll be able to identify bottlenecks
and the data will enable you to better troubleshoot potential issues with your website.
There are two great services that Ubuntu suggest you can install to do all of this. The first is Nagios
(for availablility monitoring) and the other is Munin (for performance) monitoring.
Nagios
Nagios helps you monitor your websites availability. That isn't just to show you whether it is up and
running, it is far more comprehensive than tha B