Move all messages from deadletter queue back into main queue of subscription

Question

My service consumes messages from an Azure Service Bus subscription. A dependency of my service was down for a while, which caused a lot of messages to end up in the deadletter queue (DLQ). Now that the service is back up, I want to reprocess all messages from the DLQ. How can I move/resubmit all messages from the DLQ back in to the main queue.

Restrictions:

• It's thousands of messages, so manually handling them isn't feasible.
• The topic has about ten subscriptions. I don't want to resubmit the messages to the topic, because then all subscriptions would receive the messages, leading to double-processing.
• I don't want to run the service against the DLQ directly, because some messages are broken and cause permanent errors, i.e. they would end up in the DLQ again, which would lead to an infinite loop. Moreover, the broken messages are put back at the front of the queue, effectively starving healthy messages that come after the broken ones.

Answer 1

I realize this is a while after the original post but if anyone else stumbles on this problem, there is a fairly handy solution baked into the Service Bus Explorer (which I have found to be incredibly handy with ASB development).

After connecting to your Service Bus and finding the needed namespace, find the desired topic and subscription with the deadletters in it. From there Right Click and Receive Deadletter Queue Messages and hit OK.

From there, highlight which you would like to send back to the main queue and hit Resubmit Selected Messages in Batch Mode.