How to Configure the Redis Object Cache Plugin on WordPress Hosting at DomainsFoundry

This guide explains how to configure the Redis Object Cache plugin by Rhubarb Group on WordPress hosting provided by DomainsFoundry.

Redis object caching can improve WordPress performance by reducing database queries and speeding up dynamic page generation.

About the Plugin

This guide is specifically for the Redis Object Cache plugin:

Redis Object Cache

Official plugin documentation is available here

Install the Redis Object Cache Plugin

  1. Log into your WordPress Admin area
  2. Go to Plugins > Add New
  3. Search for Redis Object Cache
  4. Install and activate the plugin

Configure Redis for DomainsFoundry Hosting

DomainsFoundry WordPress hosting uses a Unix socket connection for Redis.

Add the following configuration to your wp-config.php file before:

/* That's all, stop editing! Happy publishing. */

Add:

define( 'WP_REDIS_SCHEME', 'unix' );
define( 'WP_REDIS_PATH', '/tmp/redis.sock' );
define( 'WP_REDIS_PORT', 0 );

Optional Recommended Configuration

For improved compatibility and performance, you may also add:

define( 'WP_CACHE', true );
define( 'WP_REDIS_CLIENT', 'phpredis' );

Example full configuration:

define( 'WP_CACHE', true );

define( 'WP_REDIS_CLIENT', 'phpredis' );

define( 'WP_REDIS_SCHEME', 'unix' );
define( 'WP_REDIS_PATH', '/tmp/redis.sock' );
define( 'WP_REDIS_PORT', 0 );

Enable Object Cache

Once the configuration has been added:

  1. Log into WordPress Admin
  2. Go to Settings > Redis
  3. Click Enable Object Cache

If configured correctly, the plugin should report a successful Redis connection.

Troubleshooting

Connection Failed

If Redis cannot connect:

  • Verify the wp-config.php entries are correct
  • Ensure the configuration is added before the “Happy publishing” comment
  • Confirm Redis is enabled on your hosting account

OOM Command Not Allowed Error

If you encounter:

OOM command not allowed when used memory > 'maxmemory'

this indicates the Redis memory allocation has been exhausted. Contact the DomainsFoundry support team for assistance.