If anyone has been around MB as long as I have we can remember the Event Broker which was the pub/sub engine. I’ve been hard-pressed to ever use it for EAI – there have been some specific use-cases but they usually involved large number of clients who were able to self-register. I guess that’s what the biggest roadblock was that most enterprise apps gave us an end-point/data format to write to vs. the ability to register themselves in a pub/sub broker.
Fast forward to the latest iterations of Message Broker/MQ we no longer have an event broker and the pub-sub engine has been ‘pushed’ into MQ itself. We also have a combined MQ/MB admin explorer that allows us to register topics and manage subscriptions giving us all the tools we need to use pub/sub for EAI.
In the above design we can easily add/change endpoints without affecting publishers. In fact the publishers are truly decoupled from the end-point systems and even end-point system changes do not have an impact on other subscribers. Throw in an enterprise canonical model and voila you have an enterprise architecture that allows for isolated changes and reduced QA cycles.
For those of us who have been using WebSphere Message Broker since the ‘MQSI’ days I recommend you rethink your flow design and incorporate pub/sub in your interfaces.