We are using the broker ActiveMQ Artemis 2.26.0, and I'm trying to set up a redelivery mechanism on a queue.
I would like for some messages to be retried for 72h maximum with progressive back-off. After 72h the message should be sent to a DLQ.
The doc states that both mechanisms of message redelivery and dead-letter queue can be combined, so I tried the following, using the examples provided with ActiveMQ Artemis:
broker.xml:
<address-settings>
<!--override the redelivery-delay for the example queue-->
<address-setting match="exampleQueue">
<redelivery-delay>30000</redelivery-delay>
<redelivery-delay-multiplier>2.5</redelivery-delay-multiplier>
<dead-letter-address>deadLetterQueue</dead-letter-address>
<max-redelivery-delay>259200000</max-redelivery-delay>
</address-setting>
</address-settings>
<addresses>
<address name="deadLetterQueue">
<anycast>
<queue name="deadLetterQueue"/>
</anycast>
</address>
<address name="exampleQueue">
<anycast>
<queue name="exampleQueue"/>
</anycast>
</address>
</addresses>
It seems that with this configuration the message are sent to deadLetterQueue after 10 redeliveries (default value of max-delivery-attempts).
How do I combine these values to fit my scenario?
TL; DR; you need to set a max-delivery-attempts value greater then 10
The total delivery delay is a geometric series so it is <redelivery-delay>*(1-<redelivery-delay-multiplier>^<max-delivery-attempts>)/(1-<redelivery-delay-multiplier>)
In your case the total delivery delay is 30000*(1-2.5^10)/(1-2.5)=190714863 that is less then 72h (259200000) so to fit your scenario you need to set a max-delivery-attempts value greater then 10, i.e. with max-delivery-attempts = 11 the total delivery delay is 476817158 (132h) that is greater than 72h.