OPcache is a caching engine which is built in to PHP 5.5 and later.
From php.net:
- OPcache improves PHP performance by storing precompiled script bytecode in shared memory, thereby removing the need for PHP to load and parse scripts on each request.
At DreamHost, DreamPress uses OPcache as a replacement for XCache.
How to enable OPcache for PHP 5.6 and above
OPcache is already compiled with PHP 5.5 , 5.6 and 7.0. To enable it on your site, create a PHP.ini file. In that file add the following depending on which version of PHP you're using:
PHP 5.6
zend_extension=/usr/local/php56/lib/php/extensions/no-debug-non-zts-20131226/opcache.so
PHP 7.0
zend_extension=/usr/local/php70/lib/php/extensions/no-debug-non-zts-20151012/opcache.so
How to check if OPcache is functioning
Checking in a phpinfo.php file
You can confirm if OPcache is functioning by creating and viewing a phpinfo.php file. View the following article for details:
When viewing your phpinfo.php file, you should see the following:
If you do not see OPcache listed, view the troubleshooting section in the PHP.ini article for assistance:
Checking via the command line
To see if the module was installed correctly, you can run the following command. You should see the OPcache settings appear:
[server]$ php-5.6 -i | grep opcache
Runtime configuration options
View the following link for a list of available runtime configurations you can use:
Using OPcache with WordPress
DreamPress
OPcache has replaced XCache for all DreamPress sites. OPcache is enabled by default which you can see in a phpinfo.php file as mentioned above.
WordPress plugin
The OPcache Dashboard plugin is useful to reset OPcache when WordPress has updated. It also allows you to view how much memory OPcache is currently using.
