How does memcache with MySQL work?

Question

I am trying to understand (and probably deploy) memcached in our env.

We have 4 web servers on loadbalancer running a big web app developed in PHP. We are already us

Answer 1

There are several examples on how memcache works. Here is one of the links.

Secondly, Memcache can work with or without MySQL.

It caches your objects which are in PHP, now whether it comes from MySQL, or anywhere else, if its an PHP Object, it can be stored in MemCache.

APC gives you some more functionality than Memcache. Other than storing/caching PHP objects, it also caches PHP-executable-machine-readable-opcodes so that your PHP files won't go through the processes of loading in memory-> Being Comiled, rather, it directly runs the already compiled opcode from the memory.