Azure Service Bus - cancelled scheduled messages getting re-queued

Question

I'm using the latest Java bindings (v3.1.3) for Azure Service Bus: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/servicebus

When I create a new queue client, schedule a message, and cancel it...

QueueClient sendClient = new QueueClient(new ConnectionStringBuilder(connectionString, queueName), ReceiveMode.PEEKLOCK);
long sequenceNumber = sendClient.scheduleMessage(message, instant);
...
sendClient.cancelScheduledMessage(sequenceNumber)

...the code appears to work as intended: The active message count goes to 0. But as soon as the scheduled message gets to the time it was supposed to be scheduled (I tested with 10 seconds and 100 seconds in the future), the message sometimes gets re-queued with a new sequence number. I'm not getting any errors when scheduling or cancelling the messages. Is there something I can do to make sure cancelled messages don't get re-queued?

The same message with a different sequence number would indicate it's a duplicate. Wherever it's your code or the SDK, I cannot see from the shared snippet above. To rule out an issue with the API, raise an issue under the repo with the repro code you've provided. Cheers. — Sean Feldman

Joey Cai Joey Cai · Accepted Answer · 2019-12-31T08:24:08

You can schedule messages either by setting the ScheduledEnqueueTimeUtc property when sending a message through the regular send path, or explicitly with the ScheduleMessageAsync API. The latter immediately returns the scheduled message's SequenceNumber, which you can later use to cancel the scheduled message if needed.

Cancels the enqueuing of an already sent scheduled message, if it was not already enqueued. This is an asynchronous method returning a CompletableFuture which completes when the message is cancelled.

So, I suggest that you could use cancelScheduledMessageAsync to cancel scheduled message.

Azure Service Bus - cancelled scheduled messages getting re-queued

1 Answers