I'm running nginx 1.0.4 with Passenger 3.0.11 and Rails applications and I've noticed that on every request I made, it takes about 5 seconds to respond for the first request, if I reload it, after the first request completes, it's fast but if I wait for a minute for example, again the new first request takes time.

Is this normal or could be something wrong with my configs?

OS: MacOSX 10.7.3