Hi Eric, I think you and I have run into the same problem. Please check below.
Farshad http://www.nabble.com/Question-about-Queue-destinations-in-network-of-brokers-td25776018.html Eric Van wrote: > > ActiveMQ 5.3.0_SNAPSHOT (Sep 8th according to the snapshots listing) > > I'm running into an issue with the store and forward feature of > activemq, which I using in an attempt to create a highly available > distributed queue. I'm trying to figure out if the issue is a > misconfiguration on my part, expected behavior of activemq, or a bug. > > The summary of the problem is that given 2 brokers, B1 and B2, which > each have one consumer, C1 and C2, which are subscribed to the same > queue. If I stop a consumer on one of the brokers, the pending > messages from that broker are not always forwarded to the other broker > which still has a consumer, leading to those messages getting > indefinitely stuck. > > The steps I use to reproduce this scenario are as follows (Note: all > producing and consuming is performed over the stomp transport): > > Couple notes about the consumers: > - they have a prefetchSize of 40 > - the processing of messages can take some time, so for the purposes > of this exercise, I've created a simple consumer that sleeps for 10 > seconds before sending the message ack (using client-individual ack > mode) > > 1. start both brokers (B1 and B2). The consumers (C1 and C2) are not > yet running. > 2. produce a few thousand messages to B1 > Note: B1 now has a few thousand pending messages and B2 has 0. > 3. start consumer C2 (listing for messages from B2) > Note: messages are are successfully received and begin processing > (monitoring the brokers shows pending messages decreasing). Now B2 > has all the pending messages and B1 has 0. > 4. start consumer C1 (listing for messages from B1) > Note: no messages are received, which is another issue I have since > B2 now has thousands of pending messages which C1 could help > process, but instead sits idle while C2 is forced to handle all the > messages. > 5. stop consumer C2 > Note: now I have thousands of messages sitting on B2 and 0 on B1 > where a C1 is alive and ready to handle them. So at this point, > despite having a consumer running, thousands of messages are stuck > in the queue. > 6. stop consumer C1 > Note: now I have no consumers. Stopping and restarting C1 has no > effect on the pending messages sitting on B1's queue. > 7. stop both brokers > 8. start B1, then start B2 > 9. start C1 > Note: now all messages have migrated from B2 to B1 and C1 is again > processing messages. > > So after step 5, the only way to recover from the stuck messages is to > restart the brokers. > > Below is my current connector config which I have on both brokers. > I've tried playing with the various properties of the connector, but > it seems as though no matter what I try the above scenario continues > to occur. > > <networkConnector > name="default-nc" > uri="multicast://default?group=${broker.group}" > dynamicOnly="true" > networkTTL="25" > suppressDuplicateQueueSubscriptions="true"/> > > > So, is this an activemq bug? Am I mis-using activemq? Is there some > other way to achieve a highly available distributed queue? > > Any help in this regard is greatly appreciated. > > -- > eric > > -- View this message in context: http://www.nabble.com/Issue-creating-a-distributed-queue-using-store-and-forward.-tp25790672p25803310.html Sent from the ActiveMQ - User mailing list archive at Nabble.com.
