Question

I want to write a script (in bash or Perl on linux) which monitors the Apache and restarts the Apache in case it exceeds X% CPU.
I understand that I need to get the total CPU usage of Apache since it opens child process.

How can I get the total CPU usage of Apache?

Answer 1

Try the following, but make sure to update the Apache-process name with your actual one (mine is httpd):

ps u -C httpd | awk '{sum += $3} END {print sum}'

This will get a list of all apache processes running and sum the %CPU column of ps‘s output using awk.