Getting started

Install CachePilot from your beta account, activate it and check the result. Autopilot does the setup on its own; this page shows what happens and how to verify it.

Requirements

• PHP 8.3 or later with the phpredis extension
• WordPress 6.4 or later, tested up to 7.1
• Redis 6.0 or later
• An approved account in the CachePilot beta

The details, including what CachePilot does not support, are on the page requirements.

How CachePilot finds Redis

On activation CachePilot tries these places in this order and takes the first Redis server that answers. Each attempt waits at most 0.3 seconds.

1. CACHEPILOT_HOST or WP_REDIS_HOST in wp-config.php, together with port, password and database constants
2. The environment variable REDIS_URL
3. The environment variables REDIS_HOST, REDIS_PORT and REDIS_PASSWORD
4. Unix sockets at /var/run/redis/redis.sock, /var/run/redis/redis-server.sock, /run/redis/redis-server.sock, /run/redis/redis.sock and /tmp/redis.sock
5. 127.0.0.1 on port 6379
6. localhost on port 6379
7. The host name redis on port 6379, only inside a container

When a server answers, CachePilot installs the object cache drop-in and starts Autopilot. An existing object-cache.php of another plugin is backed up first.

define( 'WP_REDIS_HOST', '127.0.0.1' );
define( 'WP_REDIS_PORT', 6379 );
define( 'WP_REDIS_PASSWORD', 'your-redis-password' );
define( 'WP_REDIS_DATABASE', 0 );

Check the installation

With WP-CLI, one command writes a value through the object cache and directly to Redis, reads it back and deletes it:

wp cachepilot test

It prints the ping time, then Object cache write and read: ok and Redis write, read and delete: ok, and ends with Success: Redis and the object cache work. For the connection details run:

wp cachepilot status

To check the page cache, request a page without being logged in and look for the header X-CachePilot-Cache: HIT. The first request stores the page, the second comes from the cache:

curl -sI https://example.com/ | grep -i x-cachepilot

What Autopilot does next

• It switches on the modules that fit your plugins, for example WooCommerce, ACF, WPML, WCML or WP Rocket.
• One minute after it switches on Page Cache or Minify, the safety check loads your pages and switches the module off again if something breaks.
• 30 seconds after a plugin, theme or WordPress update it analyses the site again and empties the page cache.
• Every hour it repairs a missing, foreign or outdated drop-in and warns when Redis memory is full.
• Once a week it e-mails the site admin, but only when it changed something or a problem needs attention.