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xmitq · Posted: Tue Oct 07, 2003 12:56 pm Post subject: Question on MA0C (Pub/Sub)

We have a simple pub/sub model using three machines:

Publisher SUN
Broker NT
Subscriber SUN

Both the Publisher and Subscriber are JMS applications using the TCF.
All machines have MQSeries 5.3 CSD 4 (ok WebSphere), and all messages are persistent and the subscriber is using durable subscriptions.

I have two questions:

1: When publishing to our own STREAM QUEUE, we do not have a problem. The durable subscriber can connect and retrieve the messages. However, when the subscribing application stops and restarts some time later and tries to re-subscribe using the unique id (as it did before), it fails as the unique id is already in use. Therefore the subscribing application is locked out.

When the DEFAULT STREAM queue is used for publications, the subscriber does not have any problems.

Can someone shed any light on this please?

2: Where can I find information regarding what JMS is doing under the covers during the publish event and subscribe event. During the publish event it appear the JMS under the covers is sending a message to the broker to establish if the broker is running and that the channels are running. If this 'check' fails then the publish message is not sent. Where can I go to get information on how JMS works with pub/sub.

Thanks