Starting php-fpm: [07-Jul-2014 17:52:33] WARNING: [pool app-execute] listen.backlog(0) was too low for the ondemand process manager. I updated it for you to 128

Well that is unfortunate, not sure why using on-demand required a backlog of 128. Essentially this php-fpm pool runs jobs then the workers automatically exit. So essentially they spawn run and die.

pm = ondemand
pm.max_children = 100
pm.process_idle_timeout = 3s;