Messaging

Part 1

Ok. Here comes the money shot. Every previous entry was just a lead up to this. What you really want to do with Websphere is create a messaging based application, if not, then why are you using it? Everything else can be done with your favorite servlet container except (really) messaging with MDB’s. Oh sure, Spring says they can do it but until I see an example of a fully transactional bean accepting a message from a iSeries MQ installation (EBCDIC -> ASCII) sucessfully using header properties and dynamic queues, I ain’t gonna believe it.

One of the biggest changes from WAS 5.1 -> WAS 6.1 was in the messaging portion of the container. You can now fully use the internal messaging provider which means you don’t have to install MQ (or whatever) on your local development machine. Another major change is they have deprecated Listener Ports (which shut down when confused) in favor of Activation Specs (basically, properties files).

Configuring a messaging based application using Jython consists of the following steps, in order:

1) Create a SI (Service Integration) Bus (Sets the name)
2) Add a SI Bus Member (Sets the properties)
3) (optional) Create MQ Client Link (Allows client connections)
4) Add Queue(s) to the SIBus
5) Add a JMS Queue Connection Factory
6) Add JMS Queues (These are tied to the SIBus Queues)
7) (optional) Add Activation Specs (Links your MDB’s to your Queues)

The next posts in the series will give examples in Jython for all the above actions. Check back or add any questions or comments.