By Dave.Cabelus-Oracle on Aug 30, 2013
In WebLogic 12.1.2, we enhanced the way that you can configure JMS servers, stores, and subdeployments so that the JMS subsystem can automatically scale with the Managed Servers in a cluster. We call this Elastic JMS. My friend Maciej Gruszka calls it Magic JMS!
Here are some details:
JMS Servers: In releases before WebLogic Server 12.1.2, each JMS Server was individually configured and targeted at a single Managed Server. It didn’t matter whether or not that Managed Server was part of a cluster. Starting in WebLogic Server 12.1.2, you can target a JMS Server at a cluster. Under the covers, WebLogic spins up a JMS Server on each managed server in the cluster. If you add or remove servers from the cluster, JMS Servers are added or removed automatically.
WebLogic Persistent Stores: Like JMS Servers, in releases before WebLogic Server 12.1.2, each WebLogic Persistent Store (file store or JDBC store) was individually configured and targeted to a single Managed Server, clustered or not. In WebLogic Server 12.1.2, you can target a WebLogic Persistent Store at a cluster. Under the covers, WebLogic creates a store instance on each Managed Server in the cluster. Each instance of a file store uses the same path to either a shared file system or to a local file. Each instance of a JDBC store uses the same JDBC data source, but gets its own underlying tables.
Subdeployments: A subdeployment defines the list of JMS Servers that will host a queue or topic. In releases before WebLogic Server 12.1.2, when you defined a subdeployment for a distributed queue or topic, you listed each JMS Server in the cluster. When you scaled up the cluster by adding a Managed Server and a corresponding JMS Server, you also needed to update the subdeployment with the new JMS Server. Starting in WebLogic Server 12.1.2, subdeployments are much simpler. You can list a single JMS Server that is targeted at the cluster. When you scale up the cluster, the distributed queue is automatically extended to the new JMS Server instance without any changes to the subdeployment.
Pulling it all together: By using cluster targeted JMS Servers and Persistent Stores, you get some nice benefits:
Check out the documentation at http://docs.oracle.com/middleware/1212/wls/JMSAD/dynamic_messaging.htm or see my video at for more details.