Introducing MAx Cache (Beta): Apache Module for Accelerating WordPress Performance

At CloudLinux, we're committed to building performance solutions that help hosting providers run websites faster and more efficiently. As part of our AccelerateWP performance optimization solution, we're excited to announce the beta release of MAx Cache. It's an Apache module that changes how WordPress sites handle requests by running PHP only on cache misses, while cached pages for subsequent requests are served by Apache without invoking PHP. The result: significantly faster page load times.

The PHP Performance Bottleneck

Running PHP is expensive. One of the key ways to speed up websites is to completely bypass it for most requests. Traditional WordPress caching solutions often still require PHP to handle routing decisions, process user agent information, evaluate headers, and determine which cached page to serve - even when serving static content.

Previously, AccelerateWP handled all routing in PHP. While functional, this approach adds processing overhead compared to solutions where routing decisions are made at the web server level.

The Solution: MAx Cache (mod_maxcache) Apache Module

We've created mod_maxcache, an Apache 2.4 module that moves the decision-making process from PHP to C.

How It Works

The module computes cache-key inputs — including device type, WebP support, logged-in user status, dynamic cookies, and normalized query strings —  and exposes them to .htaccess rules as variables.

AccelerateWP uses these module-provided variables to build a proper cache path in the .htaccess configuration, allowing Apache to serve the correct static page without invoking PHP. 

In short, the module makes routing decisions in C and serves pre-generated pages immediately, bypassing PHP entirely for cached requests.

Key Benefits:

• Server-level routing: Decision-making happens in C at the Apache module level, not in PHP.
• PHP runs only on cache misses: The first request generates the static page, and for subsequent requests the cached version is served directly from Apache. There is no PHP execution for pages that are cached already.
• Cache key generation: Automatically handles device detection, WebP support, user authentication state, and query string normalization
• Integration options for other caching plugins: Offers integration possibilities for other caching plugins such as WPRocket, WP Super Cache, Cache Enabler, W3 Total Cache (W3TC), WP Fastest Cache to take advantage of the performance improvements offered by MAx Cache.
• Superior to RewriteRule-based solutions: Most WordPress caching plugins rely on Apache's RewriteRule module to serve cached pages, which is slow, difficult to debug, and not accurate with low trust rules. MAx Cache provides a more efficient solution without additional overhead for Apache.

Performance Impact

By moving routing logic from PHP to a native Apache module, MAx Cache reduces PHP overhead and significantly improves performance.

In our internal benchmarks, MAx Cache:

• Increased RPS by ~2x
• Improved TTFB by ~2x
• Decreased load, CPU, and memory usage for PHP pages by ~2x.

Control Panel Support

Currently, MAx Cache supports cPanel on CloudLinux 7/8/9 Shared Pro, Admin, and Solo editions. Our upcoming plans include adding support for Plesk, DirectAdmin, and no-panel installations, expanding the availability of this performance solution across different hosting environments.

How to get started

In order for MAx Cache to function on a website, it needs to be deployed at the server level, and also activated in AccelerateWP by the WordPress administrator at the website level.

Installation steps for hosting providers

1. To install packages, run the following commands:

yum install accelerate-wp cloudlinux-site-optimization-module libmaxcache --enablerepo=cloudlinux-updates-testing

yum install ea-apache24-mod_maxcache --enablerepo-cl-ea4-testing

2. Enable MAx Cache for all available domains:

cloudlinux-awp-admin maxcache enable --all