I have a heavy traffic site that gets about +200 concurrent users and receives 4k+ uniques daily. My site seems to load slow for a few minutes and then fast for a few minutes and the pattern continues on.
I am running Ubuntu 10.04 LTS 32bit. It uses nginx as the webserver and php-fpm. I also have APC installed. My site uses Wordpress with caching plugin.
This is what my top looks like http://pastebin.com/JDULwAxm
This is nginx conf http://pastebin.com/GXHTw9dG
This is php-fpm conf http://pastebin.com/NWznCs3r
This is mysql conf http://pastebin.com/sXRT7Jf9
Can anyone help me optimize to make the site stable? If you think my configurations are alright then do you think it's the host's side that is at fault for the instability?