We have news portal. We have 5 identical dedicated boxes. 2xE5620, 16GB ram, 4x146gb 15k sas raid10. at this time bottleneck is mysql.
One box is load balancer (nginx), two boxes (C,D) is nginx & phpfpm, one is mysql backup and one box is mysql.
At this moment caching is on box C and D. we use memcached, where are stored result from mysql. Sometimes in page is white boxes (no content loaded). I already made atomic inserts into memcached and made full debugging of memcached operations.
So, i think that maybe must made static files. When new article is published, then create static html file for it and use server side includes for comment count displaying and same comment content displaying. Then nginx can cache mostly used files and serve them from memory. With static pages we could also speed up page loading time.
I am thinking about cookie less domain, but i am not sure if that helps, because network pipe not bottleneck.
Question is: what caching system/model to use?