Workload balancing in clusters

If a cluster contains more than one instance of the same queue, IBM® MQ selects a queue manager to route a message to. It uses the cluster workload management algorithm, and a number of cluster workload-specific attributes, to determine the best queue manager to use.

Suitable destinations are chosen, by the cluster workload management algorithm, based on the availability of the queue manager and queue, and on a number of cluster workload-specific attributes associated with queue managers, queues, and channels. These attributes are described in the subtopics.

Note: Specify the cluster workload channel attributes on the cluster-receiver channels at the target queue managers. Any balancing you specify on the matching cluster-sender channels is likely to be ignored. See Cluster channels.

After you configure the cluster workload-specific attributes, if the configuration does not behave as you expected, explore the details of how the algorithm chooses a queue manager. See The cluster workload management algorithm. If the results of this algorithm do not meet your needs, you can write a cluster workload user exit program, and use this exit to route messages to the queue of your choice in the cluster. See Writing and compiling cluster workload exits.