We're working on moving from v0.9.5 to 2.1 right now and as you can imagine there have been quite a few changes :).
One of the improvements we've been looking forward to is the different approach to heartbeats since we had observed the bottleneck in ZK's transaction log. I've seen references to this change in this list: https://issues.apache.org/jira/browse/STORM-2693 Could anyone describe the default behavior of heartbeats in 2.1 vs 1.2? I understand that in 1.2 you can use Pacemaker to remove the dependency on ZK for heartbeats. But I haven't seen any up-to-date information on how a cluster should be set up today. If we are trying to avoid the ZK bottleneck do we still need to use Pacemaker? Or do we get that for free now? Thanks, Andrew
