A WebLogic Server cluster consists of multiple Managed Server instances running simultaneously and working together to provide increased scalability and reliability. A JMS distributed destination usually has a set of members distributed across multiple Managed Server instances, with each member hosted by a separate JMS server instance. For more information, see Understanding WebLogic Server Clustering in Administering Clusters for Oracle WebLogic Server.
The following topics provide information about how the JMS resource adapter load balances outbound WebLogic JMS communication:
The JMS resource adapter supports RMI object load balancing using WebLogic JMS connection factories to create connections and sessions that point to different WebLogic Server instances.
For more information, see Load Balancing in a Cluster in Administering Clusters for Oracle WebLogic Server.
Load balancing to WebLogic distributed destinations (DDs) is automatically supported without additional configuration. DDs appear to the JMS resource adapter as a single, logical destination. Both a distributed destination and its members are advertised in WebLogic JNDI. When messages are load balanced to a member of a distributed destination on a WebLogic Server instance that is different from the instance that the JMS resource adapter's managed connection points to, the Interposed Transaction Manager (ITM) of the managed connection is able to enlist the messages sent to a different WebLogic Server instance, transparently relaying XA calls to the corresponding transaction coordinator on that instance, if necessary.
Note:
Individual distributed topic members must be referenced when creating, using, and unsubscribing a durable subscription.