The organization of topics and the granularity of subscriptions to them is an important part of a publish/subscribe application’s architecture. A message delivered to a topic is distributed to all consumers that are subscribed to that topic. Ensuring that a clustered application gets exactly one copy of each message, and parallel processing of topics messages may require significant additional configuration, coding, and message hops. To address such limitations, WebLogic JMS provides load balancing and failover for physical JMS destination members (queues or topics) through its "Distributed Destinations" that applications can leverage.
In a typical SOA Suite production cluster deployment, load balancing the JMS topic messages against the SOA composites will be a common requirement. It is to ensure that messages are evenly distributed (load balanced) to SOA cluster members, and to avoid duplication in some scenarios. This can be achieved by configuring the SOA JMS Topic to use a "Distributed Destination" setting the appropriate forwarding policy and other advanced parameters.
Here is a sample WLST offline script:
Note that there in no support to define the UniformDistributed Queue/Topic in weblogic application extension templates' file config/jms/<%jms-module%>-jms.xml (as of the latest SOA PS6 release). Refer the "Fusion Middleware Programming JMS for Oracle WebLogic Server" guide for more details on WLS JMS Distributed Destinations.
