I am using activemq-core-5.7.0. We are using broker-to-broker communications with conduit subscriptions to reduce redundant messaging. We have a top-tier coordinating server, call it broker A. We have two routing servers that each connect to A, call them broker B and broker C. We have remote applications that connect to both B and C for redundancy, and client applications that connect to only one of B or C. We only use topic messages for all communications between nodes. <http://activemq.2283324.n4.nabble.com/file/n4659548/network.png> Normally, all is well. However, we noticed some problems in the remaining network when nodes were lost. We were able to find steps to recreate the problem as follows. Start the nodes in the order A, B, C, Remote, Client1, Client2. Stop node C. At this point, some of the consumers from the Remote were lost from Client1, while others remained. If we send a message from Client1 on one of the topics that was lost, it doesn't leave the local broker.
Tracing into the source of the network bridge, I suspected that ConduitBridge.checkPaths was preventing one of the consumer paths from being added to the list. I've attached a unit test, ConduitMockTest.java <http://activemq.2283324.n4.nabble.com/file/n4659548/ConduitMockTest.java> , that uses JUnit, EasyMock, and activemq, that shows how messages may stop forwarding depending on the order the consumers are added and removed from the network bridge. When I comment out the check for checkPaths, my test and our application seem to work. However, ThreeBrokerQueueNetworkTest.testDuplicateQueueSubs fails. I traced back the addition of checkPaths as a fix for AMQ-2327 <https://issues.apache.org/jira/browse/AMQ-2327> , but cannot understand why duplicate paths would be suppressed like this, when there is a flag to suppress duplicate subscriptions for topics and queues and this is checked elsewhere. Can anyone add any insights into why checkPaths exists, or what could be wrong with the attached test case for addAndRemoveSameOrder()? -- View this message in context: http://activemq.2283324.n4.nabble.com/Topic-consumers-are-lost-in-a-cyclic-network-tp4659548.html Sent from the ActiveMQ - User mailing list archive at Nabble.com.
