2 Replies Latest reply on Nov 22, 2011 5:43 AM by Andy Taylor

    Is it possible to reset a messagegroup

    magnus.hagstrom Newbie



      I have been testing out message grouping in hornetq, and wants to know if its possible to reset messagegroups on hornetq. I found a note on jboss messaging saying :


      The router will always try to route messages with the same JMSXGroupID to the same receiver.

      + * If the JMSXGroupID is not set, the receivers will be chosen by round robin.             

      + * To reset the receiver associated to a given JMSXGroupID, the producer can send a message

      + * with the JMSXGroupSeq header to 0


      Is it possible to something like this on hornetQ?


      My scenario I tested was this. Simulating taking down for ex. an App. Server


      Start hornetq

      Start 3 consumers.

      Send 10 msg with 3 different messagegroups.


      So far its all good.

      Now close down 1 consumer.

      Resend 10 msg with 3 different messagegroups.

      The 2 consumers left consumes all messages.

      Start up consumer 3 again

      Resend 10 msg with 3 different messagegroups.

      Now the 2 consumers are still consuming all messages, the new consumer dont get any messages.


      The only way I could get the load to spread evenly again was to recycle HornetQ.



      Another thing I stumbled on was that if I killed a consumer with kill -9 <pid>, none of the consumers left would get any messages until I started up that consumer again. This was tested on 2.1.0 Final, I will retest that on 2.2.5 later on and file a question on that when I tested it. Just mentioned it incase anyone reads and knows if it is a knowned bug.