Diagnostics

Object Cache Pro’s diagnostics provide a deep insight into its overall state.

You can access the diagnostics through:

• Tools > Site Health > Info
• WP CLI: wp redis diagnostics
• The Query Monitor plugin

The dashboard widget will also show some diagnostic information and errors, but not as many as the options above.

#Eviction Policy

To avoid Redis running out of memory and your site going down, it’s recommended to set Redis’ maxmemory-policy configuration option to allkeys-lru or allkeys-lfu.

If this causes too much CPU usage in your particular set up, you can use a reasonable maxttl for your setup. See configuration options.

#Exceptions

#PhpRedisMissingException

Object Cache Pro requires the PHP extension PhpRedis (3.1.1 or newer) to communicate with Redis.

If PhpRedis was installed in the environment (CLI, FPM, etc.), but you’re seeing the PhpRedisMissingException exception, be sure to load the extension in your php.ini and to restart your PHP and web server processes.

#PhpRedisOutdatedException

Object Cache Pro requires the PHP extension PhpRedis (3.1.1 or newer) to communicate with Redis.

If you’re seeing the PhpRedisOutdatedException exception you’re environment is using an outdated version of PhpRedis. If PhpRedis 3.1.1 was installed for that environment (CLI, FPM, etc.), be sure to load the extension in your php.ini and to restart your PHP and web server processes.