1 Reply Latest reply on Apr 28, 2015 9:36 AM by Justin Bertram

    Does HornetQ support Retained Publications?

    Alan Gibson Newbie

      Hello all,

       

      I have a pretty straightforward question: Does HornetQ support "retained publications"?

       

      IBM provides a pretty good definition *:

       

      By default, after a publication is sent to all interested subscribers it is discarded. However, a publisher can specify that a copy of a publication is retained so that it can be sent to future subscribers who register an interest in the topic.

       

      Deleting publications after they have been sent to all interested subscribers is suitable for event information, but is not always suitable for state information. By retaining a message, new subscribers do not have to wait for information to be published again before they receive initial state information. For example, a subscriber with a subscription to a stock price would receive the current price straight away, without waiting for the stock price to change (and hence be republished).

       

      The queue manager can retain only one publication for each topic, so the existing retained publication of a topic is deleted when a new retained publication arrives at the queue manager. However, the deletion of the existing publication might not occur synchronously with the arrival of the new retained publication. Therefore, wherever possible, have no more than one publisher sending retained publications on any topic.

       

      Unfortunately, Google hasn't come up with a definitive answer as to whether HornetQ has such a feature.

       

      Thanks in advance,

       

      Alan

       

      * IBM Knowledge Center