[JamesDLevine]

Seems kind of generic, but applicable.

In my environment we've also observed latencies associated with some of the appservers referenced, so we rolled our own thin one with low-overhead in mind. We use multiprocessing as our means to saturate multiple cores, and avoid the nuisances associated with general-purpose multithreading.

The deck covers load-balancing but doesn't cover other patterns, such as the async variety. We increasingly use queues of various sorts. Zmq & mongrel2 offer really exciting possibilities, though we haven't tried the latter at scale so far.