I haven't seen any one product that does all of that, but generally I want to separate heartbeating and status updates from the other queue functionality. ZooK

I haven't seen any one product that does all of that, but generally I want to separate heartbeating and status updates from the other queue functionality. ZooKeeper will do a lot of the heartbeating, presence, status changes, list clients, etc. I don't think it's designed to function as a queue though. I think with a combination of Redis and ZooKeeper you could get what you want.