This sub-section of the WordPress MU information contained in this blog is dedicated to one of the most important aspects in improving WPMU’s performance : caching.
There are many different ways and levels where you can do caching in WPMU, and I will cover each of them separately :
1. DataBase query cache using mysql’s built-in cache.
2. PHP op-code cache using a dedicated software like APC, eaccelerator and the like.
3. Object cache using APC or memcached.
4. Full page cache using the WP-Cache plugin.
5. Reverse proxy cache for multi-servers architectures.