Before You Create a Universal Messaging Cluster
Before you create or update a Universal Messaging cluster:

Ensure that the server instances that you want to add to the cluster are running.

Verify that the permissions on the server machines allow connections to the other servers in the cluster.

Ensure that the /naming/defaultContext channel exists only on one or none of the nodes that will form the cluster. The
Universal Messaging server instance used as a JNDI provider uses the /naming/defaultContext channel to store JMS references and JNDI objects. If channels exists on multiple nodes, you cannot create the cluster.