You should be using NewRelic by now, but do you regularly check out their blog? They have a great series of tech tips for Ruby going on right now, celebrating RailsConf. The most recent one is “Debugging Stuck Ruby Processes – what to do before you kill -9”
There are 7 great articles in the series so far, and more to come!
If you just haven’t gotten around to checking out NewRelic yet, now’s the time. As always, your free account is waiting for you.