Redis Object Cache

Object caching backend using Redis for persistent storage. Implements all methods specified by WordPress Core. Supports multisite.

The plugin supports both the Redis PECL module and the Predis library to connect to Redis.

You must install the Redis server before using this plugin!

1. Install and configure Redis. There is a good tutorial here.
2. Install the Redis PECL module or place the Predis library in the /wp-content/predis directory.
3. Add object-cache.php to the wp-content directory. It is a drop-in file, not a plugin, so it belongs in the wp-content directory, not the plugins directory.
4. By default, the script will connect to Redis at 127.0.0.1:6379. See the Connecting to Redis FAQ for further options.

Connecting to Redis

By default, the plugin uses 127.0.0.1 and 6379 as the default host and port when creating a new client instance; the default database of 0 is also used. Three constants are provided to override these default values.

Specify WP_REDIS_BACKEND_HOST, WP_REDIS_BACKEND_PORT, and WP_REDIS_BACKEND_DB to set the necessary, non-default connection values for your Redis instance.

Prefixing Cache Keys

The constant WP_CACHE_KEY_SALT is provided to add a prefix to all cache keys used by the plugin. If running two single instances of WordPress from the same Redis instance, this constant could be used to avoid overlap in cache keys. Note that special handling is not needed for WordPress Multisite.