Gossip actor jam

[rogeralsing]

Gossip Actor can get into bad state. I've seen the gossip loop go into a failed state where it never recovers. when this happens, other nodes cannot talk to this node either, and basically the cluster jams up

I believe this is related to the slow shutdown phase seen also, where stopping the gossip heartbeats takes a long time. basically the gossip actor is unresponsive.