Overview

This is a WordPress object cache backend that supports the MemCachier caching service. It requires Memcached ver. 2.2.0 PECL package or greater for SASL support.

It is a fork of tollmanz object cache, adding SASL and binary protocol support for cloud based caches.

Installation

1. Make sure you have libmemcached installed, built with SASL. See the Memcached Requirements.

2. Install the Memcached ver. 2.2.0 PECL package.

3. Define the Memcached servers and SASL credentials in your wp-config.php, as follows:

    global $memcached_servers;
    $memcached_servers = array( array( 'host', port ) );
   
    global $memcached_username;
    $memcached_username = 'sasl_username';
   
    global $memcached_password;
    $memcached_password = 'sasl_password';
   

4. Alternatively, set the environment variables, MEMCACHE_SERVERS, MEMCACHE_USERNAME and MEMCACHE_PASSWORD. The expected format for MEMCACHE_SERVERS is 'server1:port1,server2:port2,server3:port3'.

Note: If running on Heroku or AppFog, just install the MemCachier add-on and your conifguration environment variables will be set.

4. Move object-cache.php to wp-content/object-cache.php

5. To test the WordPress object cache setup, add the following code as an MU plugin:

   <?php
   $key   = 'dummy';
   $value = '100';
   
   $dummy_value = wp_cache_get( $key );
   
   if ( $value !== $dummy_value ) {
   	echo "The dummy value is not in cache. Adding the value now.";
   	wp_cache_set( $key, $value );
   } else {
   	echo "Value is " . $dummy_value . ". The WordPress Memcached Backend is working!";
   }

After adding the code, reload your WordPress site twice. On the second load, you should see a success message printed at the top of the page. Remove the MU plugin after you've verified the setup.

Credits

• wordpress-memcached-backend
• RedisLabs SASL support