You can specify the default JMS Host in the Admin Console Java Message Service page. If the Java Message Service type is LOCAL, then Enterprise Server will start the default JMS host when the Enterprise Server instance starts.
To use an MQ broker cluster, delete the default JMS host, then add all the MQ brokers in the cluster as JMS hosts. In this case, the default JMS host becomes the first JMS host in the JMS host list.
You can also explicitly set the default JMS host to one of the JMS hosts. When the Enterprise Server uses a Message Queue cluster, the default JMS host executes MQ-specific commands. For example, when a physical destination is created for a MQ broker cluster, the default JMS host executes the command to create the physical destinations, but all brokers in the cluster use the physical destination.