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

By default Redis/Valkey do not have a maxmemory-policy set in their configuration file, this means once the server’s memory limit is reached it will stop responding to commands, which in turn will crash WordPress.

It’s critical to configure your server to use eviction, for example with allkeys-lru or allkeys-lfu.

If you’re unable to set a maxmemory-policy, you can use a short maxttl for Object Cache Pro, to keep expire keys after a few minutes or hours, so that your Redis/Valkey will not run out of memory. See configuration options.