WebSphere Application Server V7.0: Concepts ... - IBM Redbooks

With some additional configuration, you can create a topology where each server
in the cluster will be configured to have an active messaging engine, thus
providing workload management as well as failover (Figure 10-4). Note that
because messaging engines can run on any server, if one server goes down,
both messaging engines will run on the remaining server.
Application server Application server
Messaging
application
Messaging
Engine
Queue point
Bus
Messages
Cluster
Queue destination
Messaging
application
Messaging
Engine
Queue point
Figure 10-4 Single bus with a cluster member: Workload management
When a queue destination is assigned to the cluster, the queue is partitioned with
each messaging engine in the cluster owning a partition of the queue. A
message sent to the queue will be assigned to one partition. The messaging
engine that owns the partition is responsible for managing the message. This
means that requests sent to a destination can be served on any of the
messaging engines running on any of the servers in the cluster.
346 WebSphere Application Server V7.0: Concepts, Planning, and Design
Messages