akka/akka — pull request #1829 by patriknw (2013-11-07 13:03:10+00:00)
Title: !clu #3683 Change cluster heartbeat to req/rsp protocol

* The previous one-way hearbeat was elegant, but comlicated to
understand and without giving much extra value compared to this approach.
* The previous one-way heartbeat have some kind of bug when joining
several (10-20) nodes at approximately the same time (but not exactly
the same time) with a false failure detection triggered by the extra heartbeat,
which would not heal.
* This ping-pong approach will increase network traffic slightly, but heartbeat
messages are small and each node is limited to monitor (default) 5 peers.