= PHP Optimizing software (APC) = May First/People Link uses [http://us2.php.net/apc the Alternative PHP Cache] PHP optimizer on all standard servers. Normally, everytime a user requests a PHP file on a web server, the server has to "compile" the php script - which means translate it into code that the processor can execute. This compilation process can be CPU intensive on busy machines. APC stores compiled PHP files in memory and re-serves the compiled files rather than re-compiling them for every request. This approach saves a lot of CPU time, making the scripts run faster. There are two good articles on the success of APC with Drupal sites: [http://blogs.activestate.com/jeffg/2007/03/apc_and_drupal_.html One by Jeffg] and another [http://2bits.com/articles/benchmarking-drupal-with-php-op-code-caches-apc-eaccelerator-and-xcache-compared.html on 2bits]. In addition, I've found a [http://realize.be/odd-and-evil-things couple] [http://drupal.org/node/48946 references] to segfaults caused by APC and PHP, which we should be wary of. If you experience trouble with APC (which will look like segfault lines in your [wiki:web_server_logs error log]), you may want to try disabling APC in your [wiki:change_php_ini_settings php.ini file] by adding: {{{ apc.enabled=0 }}}