I'm using the "WP super cache" WordPress plugin on a Ubuntu 12.04 server and found it is incompatible with php APC.
After installing and activating the WordPress plugin, the blog was down and users were getting a error page:
HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfil the request.
I noticed a segmentation fault in the Apache error log (
In the troubleshooting section of the WP super cache FAQ I noticed a description of my problem:
- The "white screen of death" or a blank page when you visit your site is almost always caused by a PHP error but it may also be caused by APC. Disable that PHP extension if you have trouble and replace with eAccelerator or Xcache.
So I commented out the apc Apache extension and restarted Apache:
> sudo emacs /etc/php5/apache2/conf.d/apc.ini ;extension=apc.so > sudo service apache2 restart
Sure enough, that fixed the problem - the blog was back up and caching enabled.
The thing is, I actually want APC cache to run as well. The opcode cache is useful. I know I could use another opcode cache but does anyone know a APC setting I can change to allow this plugin to work with APC?
Note: I also tried Ubuntu 10.10, 11.04, 11.10 and had exactly the same issue.