Message Ordering with Message Listeners

Question

          We have three Message Listeners listeners listening to JMS Queue
          for processing messages sent to the queue. Let us assume the listeners as L1,L2
          and L3. And lets says there are three
          messages that have been submitted to the queue in the order M1,M2 and M3. M1 goes
          to L1,M2 to L2 and M3 to L3. Everything is fine. When L2 finishes processing M2
          faster than the other two listeners, M4 which is submitted later does not get
          processed
          by L2. Instead it gets processed by L1. This is a very bizarre
          behaviour as it does not utilize the available lsitener L2.
          Is there any configuration setting which can change this behaviour??Or is this
          a Weblogic 7.0 Bug. Any help on this greatly appreciated.
          Thanx,
          Sankas
          

Answer 1

          Zach,
          Thanx a lot for your response. I have been trying to crack this
          for the past few days and does not seem to work. I have tried your suggestion
          of 3listeners and 6 messages. It did not do the trick. I even tried 10 messages.
          Still messages 1,4 and 7 go to the first listener even though it is not ready
          to process them.
          And thanx for the neat explaination on the MessagesMaximum thing. Actually I tried
          setting to 0 and the server does not start up properly.
          To me this issue seems to be pretty big. At least from our
          implementation point of view as the messages are not delivered
          to the available listener. Is'nt there a workaround for this??
          By telling the server that it does not want to be send any more incoming messages.
          I have tried all sorts of closes and stops on the connection and session objects.
          None of them work as the spec says they wait until the Message Listener returns
          and by
          the time it returns messages are already cached on the listener.
          So I would greatly appreciate if BEA can come up with a workaround for this
          as it is very crucial for our deployment. I am little bit surprised if this issue
          hasn't come up before.
          Thanx,
          Sankas
          "Zach" <[email protected]> wrote:
          >When you set the value to 1, there is one message in-flight at all times.
          >That is your listener has 1 message and 1 is on the way. If you have
          >3
          >listeners and send 4 messages then you will still see the behavior you
          >describe. Try sending at least 6 messages for your 3 listeners.
          >
          >In the next release we have modified this to allow you to set the value
          >to
          >zero. No messages are pre-delivered/in-flight.
          >
          >_sjz.
          >
          >"Sankas" <[email protected]> wrote in message
          >news:[email protected]...
          >>
          >> Shean,
          >> I tried making the MessagesMaximum=1 change you suggested and
          >> it does not seem to do what you have said. Is there anything
          >> else that need to be changed?If you want to look at my listener
          >> code I can email it to you.
          >> Thanx,
          >> samkas
          >>
          >> "Sankas" <[email protected]> wrote:
          >> >
          >> >Shean,
          >> > Thanx a lot for your prompt reply. I will try the
          >> >configuration change of MessagesMaximum=1. Also is it possible
          >> >if I close the session of the message listener once I receive a
          >> >message. And open it once the listener is ready to process the
          >> >next message.
          >> >
          >> >Thanx,
          >> >Sankas
          >> >
          >> >
          >> >"Shean-Guang Chang" <[email protected]> wrote:
          >> >>For async consumer WLS JMS can buildup a message pipeline for each
          >consumer,
          >> >>which is tunable on the connection factory (MessagesMaximum).
          >> >>In your case you should set the message pipeline to 1 then L2 will
          >get
          >> >>M4.
          >> >>The pipeline is used to speedup message delivery to async consumer
          >and
          >> >>WLS
          >> >>JMS will try to fill up each async consumer's pipeline in round-robin.
          >> >>Thanks!
          >> >>
          >> >>"Sankas" <[email protected]> wrote in message
          >> >>news:[email protected]...
          >> >>>
          >> >>> We have three Message Listeners listeners listening to JMS Queue
          >> >>> for processing messages sent to the queue. Let us assume the
          >listeners
          >> >>as
          >> >>L1,L2
          >> >>> and L3. And lets says there are three
          >> >>> messages that have been submitted to the queue in the order M1,M2
          >> >and
          >> >>M3.
          >> >>M1 goes
          >> >>> to L1,M2 to L2 and M3 to L3. Everything is fine. When L2 finishes
          >> >>processing M2
          >> >>> faster than the other two listeners, M4 which is submitted later
          >does
          >> >>not
          >> >>get
          >> >>> processed
          >> >>> by L2. Instead it gets processed by L1. This is a very bizarre
          >> >>> behaviour as it does not utilize the available lsitener L2.
          >> >>> Is there any configuration setting which can change this
          >behaviour??Or
          >> >>is this
          >> >>> a Weblogic 7.0 Bug. Any help on this greatly appreciated.
          >> >>> Thanx,
          >> >>> Sankas
          >> >>
          >> >>
          >> >
          >>
          >
          >