Dead Letter Pipeline Configuration

[phatboyg]

Allow the dead letter pipeline to be configured.

By default, the dead letter pipeline moves the message to the _skipped queue.

• Allow the pipeline to be configured
• Add extension methods to add the default filters

Azure Service Bus

• Add a filter to move the message to the built-in dead letter queue

[elepner]

We use MT with ASB very actively. If you implement the feature for sending messages to the built-in DLQ,I will be in seventh heaven. Let me know if I can help somehow.

[elepner]

Is it possible to add more description into this issue where I can start extending the code and how the API should look like approximately. I'd love to make PR for ASB DLQ but I don't know where to start.

[wasabii]

I want to concur with elepner. I understand why it is a separate thing. So it's addressable. But it breaks the expectations of existing management tools.

A pattern I can imagine would be to address it with query args: fooqueue?deadletter

[Crozin]

1. AWS SQS also have a native support for dead-letter queues that's basically what MT's .Use[Scheduled]Redelivery is. Not sure if there is any significant value supporting it with native mechanisms?
2. MT _skipped queue is very limited in its configuration - at least when used with AWS transport. Something I might want to configure could include things like QueueAttributes (think AWS tags for the queue, encryption etc.). The same applies for _error queue as well.

[jpeckham]

was there a way to do this with a ReceiveEndpoint that has a topic subscription. I tried with this code:

       cfg.ReceiveEndpoint("goodbye-consumer", ep =>
       {
           ep.Subscribe("goodbye-topic", "goodbye-consumer");
           /* puts into the queue's dlq "goodbye-consumer/$DeadLetterQeueue"
            * but you cannot re-deliver because it has auto forward rule from hello-topic */
           ep.ConfigureDeadLetterQueueDeadLetterTransport();
           ep.ConfigureDeadLetterQueueErrorTransport();
           ep.ConfigureConsumer<GoodByeConsumer>(context);
       });

If i fault and go into the dlq of the queue and try to 'receive messages' in azure service bus explorer i get an error.

My thinking is that there should be a way for them to go to the Topic's DLQ: goodbye-topic/$DeadLetterQueue. That is the typical management strategy of Azure Service bus. Enter the azure service bus explorer of the topic, see the DLQ items and re-send them to the topic. (Arguably i think it's dumb choice on MS part because it goes to every subscriber, but it is the way it works)

EDIT: might be a bug with service bus although i never had autoforward on this queue or the DLQ to my knowledge. Deleting everything and starting over fixed it and redelivery to the queue is superior than the topic.
https://stackoverflow.com/questions/67737252/azure-service-bus-error-cannot-create-a-message-receiver-on-an-entity-with-aut