WebSphere WebSphere Application Server Version 6.1.x Feature Pack for Web Services Operating Systems: AIX, HP-UX, i5/OS, Linux, Solaris, Windows, z/OS

Workload sharing with queue destinations

You can configure multiple messaging engines in a cluster bus member to share any workload associated with queue destinations deployed to the cluster.

See Service integration high availability and workload sharing configurations for more information about configuring messaging engines to share workload.

A queue destination deployed to the cluster is partitioned across the set of messaging engines associated with the cluster. The availability characteristics of a partition are the same as those of the messaging engine it is localized by.

Sending to a partitioned queue destination

If the producer of a message addressed to a destination is connected to a messaging engine that has a local partition of the destination, the message is handled by the local messaging engine, in other words the message is sent to the local partition.

If the producer of a message addressed to a destination is connected to a messaging engine that does not have a local partition of the destination, the message is forwarded to a messaging engine that does have a partition. Messages are workload balanced across the available partitions (partitions in messaging engines that are currently active).

Receiving from a partitioned queue destination

When a consumer session is created, the consumer is bound to one partition of the destination. If the consumer is connected to a messaging engine that has a local partition of the destination, the consumer will be bound to that partition. If the consumer is connected to a messaging engine that does not have a partition of the destination, the consumer will be bound to a partition in another messaging engine selected dynamically by the workload manager. Once bound, a consumer receives messages from the bound partition only. If the partition to which a consumer is bound does not have any messages, the consumer does not receive messages from alternative partitions, even if such partitions contain messages.

Typically you would only create a partitioned destination where the message processing load for a destination cannot be supported by a single server and there are multiple consumers. A typical use is a cluster of message-driven beans (MDBs). Each partition of the destination feeds messages to the MDBs in the local cluster server, so to ensure that all MDBs are supplied with messages, add messaging engines to the cluster and configure them so that there is a messaging engine running in each server. If you configure a partitioned destination in a cluster that does not have local consumers, it is important to have at least one consumer for each partition of the destination, to ensure that all messages are consumed. You can achieve this by configuring a sufficient number of consuming applications and configuring their ConnectionFactories to spread their connections across the messaging engines in the cluster.

Related concepts
Queue destinations
Workload sharing configuration

Concept topic

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Timestamp icon Last updated: 27 November 2008
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