Title: APC Object Cache Backend Author: Mark Jaquith Published: August 4, 2010 Last modified: May 4, 2020 --- Search plugins This plugin **hasn’t been tested with the latest 3 major releases of WordPress**. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress. ![](https://s.w.org/plugins/geopattern-icon/apc.svg) # APC Object Cache Backend By [Mark Jaquith](https://profiles.wordpress.org/markjaquith/) [Download](https://downloads.wordpress.org/plugin/apc.2.0.7.zip) * [Details](https://twd.wordpress.org/plugins/apc/#description) * [Reviews](https://twd.wordpress.org/plugins/apc/#reviews) * [Installation](https://twd.wordpress.org/plugins/apc/#installation) * [Development](https://twd.wordpress.org/plugins/apc/#developers) [Support](https://wordpress.org/support/plugin/apc/) ## Description APC Object Cache provides a persistent memory-based backend for the WordPress object cache. APC must be available on your PHP install. An object cache is a place for WordPress and WordPress extensions to store the results of complex operations. On subsequent loads, this data can be fetched from the cache, which will be must faster than dynamically generating it on every page load. The APC Object Cache backend is also compatible with [Batcache](https://wordpress.org/extend/plugins/batcache/), the powerful full page caching engine that runs on WordPress.com Be sure to read the installation instructions, as this is **not** a traditional plugin, and needs to be installed in a specific location. ## Installation 1. Verify that you have PHP 5.2.4+ and a compatible APC version installed. 2. Copy `object-cache.php` to your WordPress content directory (`wp-content/` by default). 3. Done! ## FAQ Does this work as a backend for Batcache? Yes! APC 3.1.1+ supports incrementers and handles its own cleanup of expired objects, so it works just fine for Batcache. Lower versions of APC will work, but the hits trigger will be disabled. Does this support versions of WordPress earlier than 3.3? Maybe, but I’m not going to support them, and you shouldn’t still be running them! I share `wp-config.php` among multiple WordPress installs. How can I guarantee key uniqueness? Define `WP_APC_KEY_SALT` to something that is unique for each install (like an md5 of the MySQL host, database, and table prefix). ## Reviews ![](https://secure.gravatar.com/avatar/85f1e397187c7681514f0f4b99c8aa6e022b062b24575cbdc10652e02d82caa2? s=60&d=retro&r=g) ### 󠀁[Very good](https://wordpress.org/support/topic/very-good-2530/)󠁿 [Grzegorz.Janoszka](https://profiles.wordpress.org/grzegorzjanoszka/) September 7, 2017 It reduces the number of sql queries by about half and thus reduces the server load. Highly recommended if you have the correct PHP APC modules. ![](https://secure.gravatar.com/avatar/f3fbec49f0e9d50e5ea6258a9f7c79253ae512019efa10d7565b5737594f3376? s=60&d=retro&r=g) ### 󠀁[greatly speed up WordPress](https://wordpress.org/support/topic/greatly-speed-up-wordpress/)󠁿 [Vinyl Roads](https://profiles.wordpress.org/vinyl-roads/) September 3, 2016 Easy to install. Boost website (APC totally eliminates the time of retrieving the file from disk and the time spent compiling). ![](https://secure.gravatar.com/avatar/97bbe4fe76251bd8de789468d4e055a2a38da2615beb64caba53e5aff6c24084? s=60&d=retro&r=g) ### 󠀁[Excelente Five Stars- Extra Performance](https://wordpress.org/support/topic/excelente-five-stars-extra-performance-2/)󠁿 [General Seed](https://profiles.wordpress.org/autocultivo/) February 7, 2017 Works fine, thanks for it Merry Christmas [ Read all 14 reviews ](https://wordpress.org/support/plugin/apc/reviews/) ## Contributors & Developers “APC Object Cache Backend” is open source software. The following people have contributed to this plugin. Contributors * [ Mark Jaquith ](https://profiles.wordpress.org/markjaquith/) [Translate “APC Object Cache Backend” into your language.](https://translate.wordpress.org/projects/wp-plugins/apc) ### Interested in development? [Browse the code](https://plugins.trac.wordpress.org/browser/apc/), check out the [SVN repository](https://plugins.svn.wordpress.org/apc/), or subscribe to the [development log](https://plugins.trac.wordpress.org/log/apc/) by [RSS](https://plugins.trac.wordpress.org/log/apc/?limit=100&mode=stop_on_copy&format=rss). ## Changelog #### 2.0.7 * Address potential XSS issues #### 2.0.6 * Fixed a PHP notice #### 2.0.5 * Implements `wp_cache_switch_to_blog()` * Degrades to the built-in PHP-memory cache when APC is not available (now plays with WP-CLI) * Clone objects before storing them to the local cache, so changes to them don’t corrupt the cache * Clear the local PHP memory cache when the APC cache is cleared #### 2.0.4 * `die()` when people mistakenly try to activate this as a plugin, and provide a helpful message for where they should move the file #### 2.0.3 * Parity with the Memcache backend, as much as was possible * Object cloning * Requires WP 3.1+ * Fix double-equals vs triple-equals bug with boolean true values #### 2.0.2 * Perform the `md5( ABSPATH )` calculation once per load (props jdub) * Allow users of complex `wp-config.php` setups to define `WP_APC_KEY_SALT` to guarantee key uniqueness (props jdub) * Lose the `preg_replace()` call in `::key()` (props jdub) * Rename the `incr` method to `incr2` and then conditionally add `incr` via class extension (so that Batcache can properly detect incrementor support) * Convert arrays to ArrayObject objects (APC does not cache multi-level arrays or arrays of objects, so this works around that) * Require PHP 5.2+ #### 2.0.1 * Fixed bugs in wp_cache_delete() #### 2.0 * First version in SVN * Updated to support increment/decrement and feature parity with the Memcached backend (except for multiget support) ## Meta * Version **2.0.7** * Last updated **6 years ago** * Active installations **10+** * WordPress version ** 3.3 or higher ** * Tested up to **3.5.2** * Language * [English (US)](https://wordpress.org/plugins/apc/) * Tags * [apc](https://twd.wordpress.org/plugins/tags/apc/)[backend](https://twd.wordpress.org/plugins/tags/backend/) [cache](https://twd.wordpress.org/plugins/tags/cache/)[object cache](https://twd.wordpress.org/plugins/tags/object-cache/) [performance](https://twd.wordpress.org/plugins/tags/performance/) * [Advanced View](https://twd.wordpress.org/plugins/apc/advanced/) ## Ratings 5 out of 5 stars. * [ 14 5-star reviews ](https://wordpress.org/support/plugin/apc/reviews/?filter=5) * [ 0 4-star reviews ](https://wordpress.org/support/plugin/apc/reviews/?filter=4) * [ 0 3-star reviews ](https://wordpress.org/support/plugin/apc/reviews/?filter=3) * [ 0 2-star reviews ](https://wordpress.org/support/plugin/apc/reviews/?filter=2) * [ 0 1-star reviews ](https://wordpress.org/support/plugin/apc/reviews/?filter=1) [Add my review](https://wordpress.org/support/plugin/apc/reviews/#new-post) [See all reviews](https://wordpress.org/support/plugin/apc/reviews/) ## Contributors * [ Mark Jaquith ](https://profiles.wordpress.org/markjaquith/) ## Support Got something to say? Need help? [View support forum](https://wordpress.org/support/plugin/apc/) ## Donate Would you like to support the advancement of this plugin? [ Donate to this plugin ](https://txfx.net/wordpress-plugins/donate)