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Differences in Durable and Non durable subscriptions of a topic endpoint

rdesojurdesoju Member Posts: 59

I observed a difference in message delivery pattern with the below setup:
1. a topic endpoint (Non-Exclusive)
2. Two Non Durable Subscribers
3. Two Durable Subscribers
(note: each subscriber was given a unique name so that there is no connection conflict)

When Producer published messages, Two non-durable subscribers received all copies of messages. However, messages are delivered alternatively to durable subscribers and hence each durable subscriber received half of the messages. Client program had an id (custom sequence number generated inside producer) in each message. So, DurableSubscriber1 received 1,3,5,7,9....and DurableSubscriber2 received 2,4,6,8 and so on.

Two questions:
1. Is this an expected behavior?
2. Is there any configuration setting using which we can make all DurableSubscribers receive all messages?
Please suggest.


Best Answers

  • rdesojurdesoju Posts: 59
    Accepted Answer

    Hi @marc ,
    Thank you very much for the great explanation :) !
    I have below questions after going through the information:
    1. Fan out with multiple durable subscriptions does not work without having the 'Queues' (in the middle) subscribe to the topic. Correct?
    2. Both durable and non-durable subscriptions does not show the same behavior. In case of non-durable subscriptions, all subscribers are able to receive all messages. However, in case of durable subscription, subscribers are receiving only sub set of messages in a round robin fashion as mentioned. May I know what is the reasoning behind treating these two subscription models differently?



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