Solving a WebSphere MQ Pub/Sub problem: Ready, Set, Go!
Gregory(Greg)Bowman 1000007M77 Visits (6127)
Whenever you encounter a problem, whether it is in development, test, or production, it seems you are always in a race against time to resolve it. If you are not prepared to run that race, you may find yourself crossing the finish line in the dark after everyone else has gone home. This holds true for almost any problem you may encounter. Problems within WebSphere MQ Publish and Subscribe (PUB/SUB) are no exception to that rule, but there are some things you can do to train yourself for that race if there ever comes a time when you have to run it. In particular, here are some things you can do to be READY if you find yourself racing with a WebSphere MQ Publish and Subscribe (PUB/SUB) issue.
One thing you should know to be prepared is that there were major changes to PUB/SUB between WebSphere MQ v6 and v7. Here are links to two items that will give you some idea of some of the changes:
Once you have an idea of some of the basics of PUB/SUB and some of the differences between v6 and v7, you will be better prepared to SET yourself up to get off to a fast start if you have a race against a PUB/SUB problem. If you ever encounter a PUB/SUB problem you can jump out ahead in the race by being prepared to collect the documentation that will be required to investigate the problem. In order to be prepared to collect this documentation quickly, you should practice collecting it at a time when you are not having a problem. This is an easy way to be sure you know how to do it and to be sure you are getting some output from the commands.
When you have any kind of problem in WebSphere MQ and you are not sure where to start, regardless of the problem type, you should always start in the same place. There is a technote entitled MustGather: Read first for WebSphere MQ. There are entries there for various types of problems and there are recent additions to the tables in that document to include WebSphere MQ PUB/SUB problems. In the PUB/SUB topic, there are instructions on how to collect the documentation, but please take note that you perform those tasks differently between WebSphere MQ v6 and v7.
There is also a webcast with some additional hints and tips of ways to get information about v7 Pub/Sub problems. You can refer to this link if you would like to view that information: Webcast replay: WebSphere MQ V7 Publish/Subscribe Troubleshooting Tools & Techniques
One other way to be prepared is to spend some time beforehand to try to avoid the problem. This will take some effort but it will benefit you in many ways. The most obvious way is that it may prevent problems from happening. If you never have the problem you have already won that race. If you take the time to familiarize yourself with PUB/SUB and be sure it is set up properly, you will be more comfortable working with the interfaces. This may not prevent every problem, but if you do have a problem, you would be more likely to recognize where the problem may be. In order to help you be sure you have things set up properly and to help you familiarize yourself with the interfaces, here is a list of items that you can use to help check your PUB/SUB environment. Please note that there are many more items in the WebSphere MQ Support data bases dealing with PUB/SUB but these are just a few that are specifically designed to help you step through your setup and configuration:
As Ralph Waldo Emerson once wrote:
"Without ambition one starts nothing. Without work one finishes nothing. The prize will not be sent to you. You have to win it."
If you follow the links above you can READY yourself with the knowledge of what PUB/SUB is and how it works. With a small amount of time and practice, you can SET yourself up to collect the documentation quickly. With a little help from the guides above you can GO into any PUB/SUB problem feeling prepared and confident. Those few things will help you WIN that race against time if a PUB/SUB problem ever dares to go against you.