The Storm cluster setup

Depicted in the following figure is the Storm and Zookeeper reference cluster that we set up in Chapter 2, Getting Started with Your First Topology.

We have three-node Zookeeper clusters for a three-node Storm cluster (which has one Nimbus and two supervisors).

We are using the recommended three-node Zookeeper clusters to avoid a single point of failure in the Storm set up.

The Zookeeper cluster should have an odd number of nodes. The reason for this requirement is that the Zookeeper election logic requires the leader to have an odd number of votes, and that combination is possible only when odd nodes are in the quorum, as shown in the following figure: