Normaly when you are troubleshooting an Apache server you are checking parameters that don’t have monitors for them.
With the “observate” aproach the best place too look at is:
# tail -f /var/log/apache/access.log
Things to check:
Let’s do in a basic way with:
# tail -f /var/log/apache/access.log|egrep '404|500|503|504'
But there is an advaced tool that read the logs and give you insights regarding the response codes, this tool is
Apachetop, it allows you to overlook, after that for more details you have the real logs, tail and grep as your friends.
On next post we will descrive other tools and techniques to check and test and monitor apache web servers, but we wanted to start with this “observate aproach”.