Apache and mysql error logs

I was reminded today of the important of using these logs. I was trying to remember a problem that I created the other day while trying to move the moodle directory and looked in the Apache error log and found a message that jogged my memory.

In my default Wamp setup, the following logs are located at c:\wamp\logs

apache_error.log
mysql.log
access.log (moodle access log)

The access.log file is logging every access to the moodle server. It is already 411 KB in size and that is only after about a week of life and only me hitting the server. This file most be massive on active servers.

I am trying to build a db backup script using php, and was naturally causing problems. I wanted to look at the php error log to see what was being reported. I looked in the php info page

Site|Admin|Server|PHP Info

and searched for error_log and found that the variable was not set.

I opened the php.ini file, searched for the error_log variable and found that there was already a statement there that I wanted to use. On line 639:

;error_log = "c:/wamp/logs/php_error.log"

I removed the semicolon, saved the file, restarted the Apache service and reloaded my php script page that was failing then peeked in the c:\wamp\logs\ folder and there was my brand new php_error.log file.

Moral of the story?

Know what your error log settings are and where they are being written and USE THEM.