Why do we get this in our log?

Question

Hello!
          (We use Wblogic 8.1.3)
          We have a Messaging Bridge that before was configuerd like:
          <MessagingBridge Name="MODELLISTBridge" QOSDegradationAllowed="true"
          QualityOfService="Exactly-once"
          SourceDestination="MODELLISTSource" Started="true"
          TargetDestination="MODELLISTTarget" Targets="BeanServer"/>
          ####<Dec 19, 2006 4:26:12 PM CET> <Info> <MessagingBridge> <inv1437> <BeanServer> <ExecuteThread: '7' for queue: 'weblogic.kernel.Default'> <<WLS Kernel>> <> <BEA-200031> <Bridge "MODELLISTBridge" is configured to allow degradation of its quality of service in cases where the configured quality of service can not be reached.>
          ####<Dec 19, 2006 4:26:12 PM CET> <Info> <MessagingBridge> <inv1437> <BeanServer> <ExecuteThread: '7' for queue: 'weblogic.kernel.Default'> <<WLS Kernel>> <> <BEA-200030> <Bridge "MODELLISTBridge" is configured to work in "Exactly-once" mode, and it is actually working in "Duplicate-okay" mode.>
          ####<Dec 19, 2006 4:27:12 PM CET> <Info> <MessagingBridge> <inv1437> <BeanServer> <ExecuteThread: '11' for queue: 'weblogic.kernel.Default'> <<WLS Kernel>> <> <BEA-200020> <Bridge "MODELLISTBridge" is stopped.>
          Now it is configuerd like:
          <MessagingBridge Name="MODELLISTBridge" QOSDegradationAllowed="true"
          QualityOfService="Duplicate-okay"
          SourceDestination="MODELLISTSource" Started="true"
          TargetDestination="MODELLISTTarget" Targets="BeanServer"/>
          Now we get this in our log:
          ####<Dec 19, 2006 4:22:11 PM CET> <Info> <MessagingBridge> <inv1437> <BeanServer> <ExecuteThread: '4' for queue: 'weblogic.kernel.Default'> <<WLS Kernel>> <> <BEA-200031> <Bridge "MODELLISTBridge" is configured to allow degradation of its quality of service in cases where the configured quality of service can not be reached.>
          ####<Dec 19, 2006 4:22:11 PM CET> <Info> <MessagingBridge> <inv1437> <BeanServer> <ExecuteThread: '4' for queue: 'weblogic.kernel.Default'> <<WLS Kernel>> <> <BEA-200030> <Bridge "MODELLISTBridge" is configured to work in "Duplicate-okay" mode, and it is actually working in "Duplicate-okay" mode.>
          ####<Dec 19, 2006 4:23:11 PM CET> <Info> <MessagingBridge> <inv1437> <BeanServer> <ExecuteThread: '0' for queue: 'weblogic.kernel.Default'> <<WLS Kernel>> <> <BEA-200020> <Bridge "MODELLISTBridge" is stopped.>
          Seems like the server does not like any of our settings?
          What should we do?
          How ever the messges get deliverd any way.
          Best regards
          Fredrik

Answer 1

Hi,
          Exactly-once messaging for the bridge requires (A) configuring the use of the "XA" bridge adapters for both the source and target destinations and (B) that both source and target destinations are configured to reference a connection factory that is configured with "XA transactions enabled" (or the equivalent for non-WebLogic vendors).
          The first example you wrote about configured a preference for "exactly-once" mode but also you enabled the bridge to degrade to "dups-ok" mode if the (A) and (B) requirements couldn't be met.
          The second example simply configured things to only run in "dups-ok" mode (and not to try "exactly-once" mode).
          See the bridge doc (or basically any bood or doc on messaging), for the difference in QOS between "exactly-once" and "dups-ok". Tolerance for duplicate messages is application dependent - some apps can tolerate dups, others can't.
          Tom