I once worked with ldirectord (I was shown at a local yet huge startup how they work) and I can say it's pretty awesome. You may integrate what it does at a rou

I once worked with ldirectord (I was shown at a local yet huge startup how they work) and I can say it's pretty awesome. You may integrate what it does at a router-level (newer top-class Cisco routers with modified IOS can do client-persistent –if needed– packet balancing, without having to forward also the responses) It's pretty awesome to just redirect incoming (usually small) packets and let indivual machines (placed in other farms, if needed) send the response without worrying about it.