Monit is a utility for managing and monitoring, processes, programs, files, directories and filesystems on a UNIX system. Monit conducts automatic maintenance and repair and can execute meaningful causal actions in error situations ::: " a great little utility that monitors your daemons "

in Short it lets you know when your Apache server goes doen, when you reach your pre determined memory usage. It will also restart key components should they stop working, for instance your web server ( apache ) might "crash" due to a DDOS attack or simmilar, monit will attenmt to restart said services notifying you of whats going on, depending on your mmonit configuration :::