There are many changes in WebSphere Process Server message bindings that have brought enhancements and convergence with the Java Messaging Service (JMS)-style of messaging. These message bindings include WebSphere MQ / WebSphere MQ Java Messaging Service (JMS) / JMS / Generic JMS bindings.
Introduction to WebSphere MQ Resource Adapters (RA)
The applications that need to connect to WebSphere MQ have to use the WebSphere MQ JMS J2C resource adapter (RA). This resource adapter helps in both inbound and outbound communications. The previous version of WebSphere Application Server had a WebSphere MQ JMS provider, which was used for interaction with WebSphere MQ. The WebSphere MQ JMS provider provided a set of client libraries that were located under the <WPS62_HOME>/lib/WMQ/java/lib directory. However, with WebSphere Process Server V7.0, the resource adapter is located in the <WPS70_HOME>/InstalledConnectors/wmq.jmsra.rar directory. The upgrades for the resource adapter are applied through WebSphere Application Server fix packs.
Activation specifications replace listener ports
For WebSphere MQ JMS bindings, previous versions used a facility known as Listener Ports for inbound communication. With the introduction of the resource adapter, the Activation Specifications are used instead. This approach alleviates the problems that are associated with Listener Ports and converges more towards the JMS-style of messaging.
The WebSphere Process Server V7.0 Fix Pack 3 resolves issues around the Event Sequencing functionality with the message endpoints in activation specifications.
- You can set the WAS_EndpointInitialState property on the activation specs to configure the initial status of the message endpoints.
- You can activate or deactivate the message endpoints through the administrative console on messaging exports
- You can use the wsadmin scripts to activate or deactivate message endpoints.
Dynamic response queues for message correlation
WebSphere Process Server V7.0 introduced the dynamic response queues for message correlation. Each request that passes through the messaging import will create a dynamic queue for storing the response. The target application has to honor the ReplyToDestination property and send the response to the dynamic queue. This mechanism does not require CALLBACK queues to store the correlation messages.
Failed event management in WebSphere MQ / WebSphere MQ JMS bindings
A new failed event type MQ is created starting from WebSphere Process Server V7.0. The appropriate connection factory needs to be created and should be provided it in the Event Reply Connection Factory settings on the WebSPhere MQ JMS Import and Export bindings. Whenever there are system exceptions on WebSphere MQ Bindings, a failed event of MQ type is created and stored in the recovery database.
For more information about enhancements in the message bindings, read through the Message binding enhancements in WebSphere Process Server V7.0.