Hi Joe, this sounds like a bug. Did you tested it with some newer version of ActiveMQ (as there was a lot of work in that area since 5.0.3)
Can you test newly released 5.4.0 http://repo1.maven.org/maven2/org/apache/activemq/apache-activemq/5.4.0/ and see if the problem still exists? If it's still there, it would be great if you could raise a Jira issue, ideally with a test case. Cheers -- Dejan Bosanac - http://twitter.com/dejanb Open Source Integration - http://fusesource.com/ ActiveMQ in Action - http://www.manning.com/snyder/ Blog - http://www.nighttale.net On Tue, Aug 17, 2010 at 2:00 AM, Joe Niski <joe.ni...@nwea.org> wrote: > i have a network of 2 brokers, let's call them "Remote" and "Central", > running on ActiveMQ 5.0.3, in a store-and-forward configuration. i inherited > this setup, i did not design it, but it seems like a generally solid > configuration. > > On the Remote broker, there are topics (e.g. "org.nwea.topics.license") that > have durable subscriptions to topics of the same name on the Central broker. > Messages that are published to topics on the Central broker find their way to > Remote really fast - as long as the Remote is online when the message is > published. Messages that are published when Remote is offline are never > picked up by the remote. > > i have a j2ee application that contains MDBs that are annotated to have > durable subscriptions to the topics on the Remote broker. > > The NetworkConnector configuration in the Remote broker's activemq.xml looks > like this: > > <networkConnectors> > <networkConnector name="${ApplianceID}" > userName="${networkConnectorUserName}" > password="${networkConnectorPassword}" > > uri="static://(ssl://${Central.ServerHostname}:${central_sslPortNumber})" > duplex="true" > dynamicOnly="true"> > <dynamicallyIncludedDestinations> > <queue physicalName="org.nwea.queues.central.>"/> > <topic physicalName="org.nwea.topics.>"/> > </dynamicallyIncludedDestinations> > <staticallyIncludedDestinations> > <queue physicalName="org.nwea.queues.central.>"/> > <topic physicalName="org.nwea.topics.>"/> > </staticallyIncludedDestinations> > </networkConnector> > </networkConnectors> > > In reading through the book "ActiveMQ in Action" and reviewing the online > docs at http://activemq.apache.org/networks-of-brokers.html, it seems that we > should use the default setting for "dynamicOnly", "false" (the docs say "if > true, only forward messages if a consumer is active on the connected broker"). > > However, when i set "dynamicOnly" to false, i see numerous startup errors and > NullPointerExceptions in the Remote activemq.log, and connection errors in > Central's logs. The Remote log simply reads: > [DemandForwardingBridge.serviceLocalException]: Network connection between > vm://remotebroker.msg02.nweacolo.pvt#24 and > ssl://msg01.se.nweacolo.pvt/192.168.1.94:51617 shutdown due to a local error: > java.lang.NullPointerException > > With "dynamicOnly" set to true, the log shows that existing durable > subscriptions are reconnecting during startup. > > Playing with the "prefetchSize" and "networkTTL" attributes for > <networkConnector> on Remote (vaguely recommended in the docs) doesn't seem > to have any effect. > > This seems very similar to this issue from February 2009: > http://old.nabble.com/Confusion-about-dynamicOnly-NetworkConnector-property-td22211600.html, > which didn't seem to get resolved. > > Any insight, recommendations, or help are most appreciated. > -- > > Joe Niski > IS Development | NWEA > NWEA.ORG<3D%22http://www.nwea.org/%22> | Partnering to Help All Kids Learn >
