Zookeeper-如何在集群中获取节点崩溃事件？

Question

I am using Zookeeper as a group communication framework for clustering. In my cluster, whenever a node crashes, i want an event for the same. How to do this ? Earlier i was using JGroup as the group communication framework where each of my nodes inside the cluster use to connect to the same channel and whenever a particular node crashes, Jgroup generates an event.

Answer 1

You can have each node create an ephemeral znode in zookeeper. When a node crashes, the ephemeral znode will disappear.

Now to be notified of new nodes joining and leaving, have all the ephemeral znodes be a child of the same parent znode, and register a watch on the children of the parent znode. This watch will fire when child znodes are added and removed, allowing you to see when nodes join or leave the cluster.

Remember to re-register your watch every time it fires, and be aware that if a node joins and leaves very quickly, you may miss the event.