You may have read Jo’s blog entry
Methods to reduce the load of your webserver by caching content: using lighttpd, MySQL UDF, LUA and speed everything up. He explained there how to use lighttpd and its mod_cml together with MySQL to provide a caching system directly at the webserver, and not at the PHP level.
Now, our good ol‘ friend Jan Kneschke, author of god’s own webserver lighttpd (called „lighty“), mentioned in his blog („mod_cml is dead, long live mod_cml!“) that the name and functionality of mod_cml is subject to change. Why? mod_cml is not about caching only, it’s about deciding how to handle a request.
„Any status code can be returned, any content source will be able to be queried to assemble the content (files, memcache).
The main reason is to allow us to change the names like ‘trigger_handler’ and ‘CACHE_HIT’ to something more appropriate.“