How to move a service bus messge to deadletter in service bus queue trigger function

Question

How can we move a service bus queue message to the dead letter through service bus queue trigger function

Answer 1

https://github.com/Azure/azure-webjobs-sdk/issues/1986#issuecomment-433960534

In v3, you can bind to the MessageReceiver class, which exposes methods like DeadLetter, Abaondon, Complete, etc. Example:

public static async Task ProcessMessage(
   [ServiceBusTrigger("myqueue")] string message, int deliveryCount,
   MessageReceiver messageReceiver,
   string lockToken)
{
   . . .
   await messageReceiver.DeadLetterAsync(lockToken);
   . . .
}

In this example, the message is bound as a string and the various message properties including lockToken are bound as params. You can also bind the message as a Message Type and access the requisite message properties from there. In v2 the ServiceBus SDK exposed these message methods directly on the BrokeredMessage class itself, but in the latest version of their SDK those methods no longer exist, meaning you have to bind to MessageReceiver to access them.

Edit you also need to set AutoComplete to false when you do this. https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-service-bus-trigger?tabs=csharp#configuration

Answer 2

In latest versions (5.5.1 for me), you must use the ServiceBusMessageActions class from the Microsoft.Azure.WebJobs.ServiceBus namespace. It looks like this:

[FunctionName("MyFunction")]
public static async Task Run(
    [ServiceBusTrigger("myQueue", Connection = "myConnection")]
    ServiceBusReceivedMessage message,
    ServiceBusMessageActions messageActions)
{
    ...
    await messageActions.DeadLetterMessageAsync(message);
    ...
}

The NuGet package you want to use is Microsoft.Azure.WebJobs.Extensions.ServiceBus.

Answer 3

I have not tried it but what you can do is set the MaxDeliveryCount property on the queue to 1 and then throw an exception in the function as soon as it is triggered. That way the message's delivery count will increase by 1 and Service Bus will automatically dead letter the message.

Answer 4

Reading the Dead Letter Queue messages is by creating the Azure Function Trigger in the Azure portal. In the Function, provide the name of the DLQ as “QueueName/$DeadLetterQueue” as shown in the below image

Note: If you want to access the undelivered message from the Topic then, the syntax of reading the Dead Letter Queue will be “TopicName/Subscriptions/SubscriptionName/$DeadLetterQueue”.

Now, define what should be done with the DLQ messages. Here, as shown in the below screenshot, we are sending the DLQ messages of “myqueue” to the Topic named of “queue” using the Azure Service Bus

In this manner, we can handle the DLQ messages as required very easily using the Azure Functions.