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| urbank |
 Posted: Mon Feb 19, 2007 4:48 am Post subject: How to detect broken subscriber connections |
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Novice
Joined: 14 Feb 2007
Posts: 16
Location: St. Gallen / Switzerland
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Environment:
Java / JDK 1.5.0
Webshpere MQ 6.x
JMS / Publish Subscribe
How can we find out about broken subscriber connections?
Which of the java-jms-subscriber-objects could be asked about its state?
For example, if we stop the WS-Manager and restart it (and 'strmqbrk') , our JMS subscriber clients lose their connections but from the application point of view, everthing seems to work fine (no exceptions), but messages remain in the queue.
For publishers, we get an exception if we can not send a message over existing broken connections and in that case we are can perform a reconnect.
Thanks for any help.
Last edited by urbank on Mon Feb 19, 2007 4:58 am; edited 2 times in total |
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| jefflowrey |
| Posted: Mon Feb 19, 2007 4:53 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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You can use the command line sample program amqspsd to perform a publish/subscribe dump with the base MQ Broker.
With Message Broker you can use the ConfigMgr Proxy API - there is a sample Java program in the Broker Info Center.
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| urbank |
| Posted: Mon Feb 19, 2007 6:05 am Post subject: |
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Novice
Joined: 14 Feb 2007
Posts: 16
Location: St. Gallen / Switzerland
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Thanks jefflowrey.
Sorry about asking the same again (just to make sure):
There are no java-classes to check subscription states with IBM Websphere MQ?
What parameters do I need with amqspsd to see dynamic information (about actual subscribers)?
We always see the same information about topics, if we have connected subscribers (the application runs) or not (the application is stopped and no subscribers are visual in MQ explorer).
Regards |
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| jefflowrey |
| Posted: Mon Feb 19, 2007 6:11 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
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The Base MQ broker is not written in Java.
There is a sample java version of amqspsd in the MQ sample code on the IBM website (rather than the MQ sample code that comes with the product) - if I recall correctly.
Maybe your applications are creating durable subscriptions.
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| urbank |
| Posted: Mon Feb 19, 2007 8:32 am Post subject: |
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Novice
Joined: 14 Feb 2007
Posts: 16
Location: St. Gallen / Switzerland
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ThanX.
Where can I get the com.ibm.mq.pcf.jar which is necessary to run the DumpBroker example?
Yes, we create durable subscriptions.
Last edited by urbank on Tue Feb 20, 2007 1:11 am; edited 1 time in total |
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| jefflowrey |
| Posted: Mon Feb 19, 2007 8:36 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
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That's the MS0b support pack.
The sample is not going to show you anything that amqspsd doesn't.
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| urbank |
| Posted: Mon Feb 19, 2007 11:48 pm Post subject: |
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Joined: 14 Feb 2007
Posts: 16
Location: St. Gallen / Switzerland
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Is this conclusion correct?
The only way to make sure that a subscriber is connected (in the environment described above with durable subscribers without Message Broker) is to reconnect from time to time.
Thanks a lot for your help! |
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| jefflowrey |
| Posted: Tue Feb 20, 2007 3:14 am Post subject: |
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Joined: 16 Oct 2002
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The subscriber should always know if it's connected or not - it should either get an error when trying to use it's connection, or it should get an error when the connection breaks.
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| urbank |
| Posted: Tue Feb 20, 2007 9:21 am Post subject: |
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Novice
Joined: 14 Feb 2007
Posts: 16
Location: St. Gallen / Switzerland
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Because we use JMS, we just have instances of the following classes:
TopicConnection
TopicSession
TopicSubscriber
We have implemented the MessageListener - Interface and we usually get the onMessage() method called, everything works fine so far.
If the MQServer stops and restarts, our subscriber classes do not get any events but are in a state, in which they do not get any messages any more (the onMessage() method is not called any more, even if there are messages in the queue, to which they are connected).
The question is: how could we find out (in our Java code by calling a method or what ever), if the subscriber is in this broken state?
Thanks a lot again. |
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| jefflowrey |
| Posted: Tue Feb 20, 2007 10:10 am Post subject: |
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Grand Poobah
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Using an ExceptionListener.
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| urbank |
| Posted: Thu Feb 22, 2007 12:37 am Post subject: |
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Joined: 14 Feb 2007
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| Thanks a lot jefflowrey, this is exactly what I was looking for. |
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