How to check which point is cause of problem with MQ?

Question

I use MQ for send/receive message between my system and other system. Sometime I found that no response message in response queue, yet other system have already put response message into response queue (check from log). So, how to check which point is cause of problem, how to prove message is not arrive to my response queue.

In addition, when message arrive my queue it will be written to log file.

Answer 1

You can view this in real-time using the QStats interface. The MO71 SupportPac is a desktop client that you can configure to connect similar to WebSphere MQ Explorer. One of the options it has is queue statistics. Each time you view the queue stats, WMQ resets them to zero. So the procedure is this:

1. Start MO71 and browse the queues.
2. Filter on the one queue of interest.
3. View the queue stats a couple of times.
4. You will see them reset to zero.
5. Now run your test.
6. View the queue stats again.

If the remote program actually put a message, you will see that the queue now shows one or more messages PUT.

If your program successfully executed a GET of the message, you will see GET counts equal to the number of PUT counts.

If GET and PUT both zero, the remote program never PUT the response message.

There are a few other approaches to this but this is the easiest. The opposite end of the spectrum is SupportPac MA0W which will show you every API call against that queue, or by PID, or whatever. It shows all the options so if a program tries to open the queue with the wrong options (i.e. open a remote queue for input) it shows that. But MA0W is a installed as an exit and requires the QMgr to be bounced so it's a little invasive.