Topic: Apache2 serves PHP source sometimes

[gomtuu]

I have a production Linux/Apache2/PHP4 web server that's not working quite right. Every once in a while (something like once every few thousand requests), Apache serves the PHP source of a page instead of executing it and serving the result. Note that this only happens very occasionally; over 99% of the time it works just like it should. So it's not a "you forgot to turn on PHP" problem. I've tried searching Google and this forum, but all I seem to be able to find is basic configuration stuff that would prevent PHP from working at all. I also posted this to a PHP forum and got no replies, so I hope someone here can at least point me somewhere helpful.

I don't see anything in Apache's logs or syslog that would indicate a problem. The Apache logs do show that when this happens, the size of the content served is equal to the PHP source file's size. But it otherwise looks normal. If there's any clue in the logs, I haven't found it.

If anyone can help at all, I'd appreciate it. It's not just annoying, but a potential security issue as well, so I'd like to get it fixed.

Linux 2.6.18-amd64
Apache 2.2.3
PHP 4.4.4

Thanks,
gomtuu

[tdonovan]

Since no one else seems to have reported it, and there is no information except "it happens occasionally" and "the log shows nothing helpful"
- I doubt you will get an answer based on that information alone.

Setting the Apache LogLevel to debug in your httpd.conf file might provide better information in your error log. This will make your log file grow very rapidly - so only leave it at debug until the error occurs once.

If you have a development machine, it would be a good idea to set it up as close to your production configuration as you can, then try to reproduce the problem by stress testing with something like Apache flood.

If you can reproduce the problem on your development system - you could then try removing and updating software components until the problem disappears. That should narrow down the cause. Some suggestions:

* Remove any 3rd-party modules you are using (remove them one at a time so you learn which one causes the problem)
* upgrade PHP to a more recent version (version 5.2.5 is the current release)
* upgrade Apache to a more recent version (version 2.2.8 is the current release)

I hope these suggestions are helpful.

-tom-