Apache Cookbook

Appendix B. Troubleshooting

The Apache web server is a very complex beast. In the vanilla package it includes over 30 functional modules and more than 12 dozen configuration directives. This means that there are significant opportunities for interactions that produce unexpected or undesirable results. This appendix covers some of the more common issues that cause problems, as culled from various support forums.

Troubleshooting Methodology

In the Error Log

The Apache software does quite a reasonable job of reporting the details when it encounters problems. The reports are recorded in the server’s error log, which is usually stored in one of the following places:

• /usr/local/apache/logs/error_log

• /var/log/apache/error_log

• /var/log/httpd-error.log

• /var/log/httpd/error_log

• C:\Program Files\Apache Group\error.log

Where the error log is put depends upon how you installed and configured the server; the wealth of possible locations in the list above is because popular prepackaged installation kits (from Red Hat, SuSE, etc.) each has its own preferred location. Of course, the definitive location can be determined by examining your httpd.conf file for the ErrorLog directive(s).

So the very first thing you should do when Apache appears to be misbehaving is see if the server has any comments to make.

If the messages in the error log don’t make the cause of the problem immediately clear, or if there aren’t any messages that seem to relate to the problem, it’s a good idea to crank the logging ...