We are running one frontend running NGINX and several app servers running Apache2.
There are several issues we have come across but right now I'll be documenting one of them. I'll be completing this article when I get more time.
This config is built on an Ubuntu 11.04 server.
Software is nginx, php-fpm (php5-fpm).
For performance, it's recommended to run php-fpm in SOCKET mode, instead of accessing via IP:PORT. That is the method shown below.