Redis Support Comes to Trellis

WordPress sites can benefit significantly from object caching, which stores database query results in memory to reduce server load and improve page response times. Starting with Trellis v1.26.0, we’ve added built-in support for Redis object caching to make it easier than ever to boost your site’s performance.

What’s new

The latest Trellis release introduces comprehensive object cache support that works seamlessly with your existing WordPress sites. Here’s what we’ve added:

Redis Support: A new Redis role that installs and configures Redis server with sensible defaults optimized for WordPress object caching. The configuration includes memory management, persistence options, and security settings tailored for production use.

Environment Variable Integration: Automatic configuration of WordPress environment variables (WP_REDIS_HOST, WP_REDIS_PORT, etc.) based on your site configuration, eliminating manual setup.

Conditional Installation: Redis and Memcached are only installed when actually needed by your sites.

Redis Configuration

Enabling Redis object caching is straightforward. In your wordpress_sites.yml, add an object_cache section to any site:

wordpress_sites:
  example.com:
    # ... existing configuration
    object_cache:
      enabled: true
      provider: redis
      database: 0

Trellis handles the rest, including:

• Installing Redis server and PHP extension
• Configuring Redis with optimized settings
• Setting up environment variables for your WordPress site
• Managing cache prefixes to avoid conflicts between sites

Separate from FastCGI Cache

One important distinction: object caching is separate from FastCGI caching (which caches full page HTML). The existing cache.enabled option continues to control FastCGI caching, while the new object_cache.enabled option controls Redis/Memcached object caching. You can use both together for maximum performance benefits.

Production-ready defaults

The Redis configuration comes with production-ready defaults including:

• Memory limits and eviction policies
• Persistence configuration for data durability
• Security settings with disabled dangerous commands
• Optimized data structure settings

For advanced users, the configuration is fully customizable through Ansible variables.

Getting started

To start using object caching:

1. Update to Trellis v1.26.0
2. Add object_cache configuration to your sites
3. Re-provision your servers with trellis provision
4. Install a WordPress object cache plugin like Redis Object Cache

For complete setup instructions and configuration options, check out our Redis documentation.

Whether you’re running a high-traffic WordPress site or just want to optimize performance, object caching support in Trellis makes it easier to implement this powerful optimization technique.