Queue manager clusters

A cluster is a group of two or more queue managers that are logically associated and can share information with each other. Any queue manager can send a message to any other queue manager in the same cluster without you needing to set up a specific channel definition, remote queue definition, or transmission queue, because all of this information is held in the repository, to which all queue managers in the cluster have access.

For example, we can create a cluster, and then set a queue on one of its queue managers to be shared in the cluster. Now, on any other queue manager in the cluster, that queue is visible as if it were a local queue, and we can just open it and put a message directly on it.

Note that sharing a queue in a cluster (a cluster queue) is different from sharing a queue in a queue sharing group (a shared queue) on z/OS® queue managers. However, on z/OS, a cluster queue manager can also belong to a queue sharing group and can share its queue definitions with other queue managers in the queue sharing group.

Also, a queue manager on any platform can be a member of more than one cluster at the same time.

Cluster support also allows more than one queue manager to host an instance of the same queue (that is, a queue with the same name). This means that we can run more than one instance of an application, each receiving messages and running independently, thus spreading the workload between queue managers.

For more information, see Distributed queuing and clusters in the IBM MQ online product documentation.