Add Support to Allow Message Abandoning and Message Dead Lettering in Azure Functions Service Bus Bindings

[trin94]

Binding Type

existing binding (azure.functions.ServiceBusMessage)

Expected Behavior

it's possible to abandon or dead letter messages (without retrying)

Relevant sample code snipped

I've tried putting messages onto the dead letter queue manually, but that did not work:

import azure.functions as func
import logging

app = func.FunctionApp()


@app.function_name(name="process-my-data")
@app.service_bus_queue_trigger(
    arg_name="msg",
    queue_name="sbq-process-my-data",
    connection="MyConnection",
)
@app.service_bus_queue_output(
    arg_name="message",
    connection="MyConnection",
    queue_name="sbq-process-my-data/$deadletterqueue",
)
def process_my_data(msg: func.ServiceBusMessage, message: func.Out[str]):
    logger = logging.getLogger(__name__)
    logger.error("writing onto dlq")
    message.set(msg.get_body())
    logger.error("writing onto dlq done")

If I change message.set(msg.get_body()) to raise ValueError(), then messages are moved to the dead letter queue (after retrying which we don't want).

Additional Information

• It would be nice if the azure.functions service bus bindings add support (and documentation) for operations like abandoning and dead lettering.
• The azure.servicebus module allows to do these advanced operations:

  with (
      ServiceBusClient.from_connection_string(connection_string, logging_enable=True) as client,
      client.get_queue_receiver(queue_name) as receiver,
  ):
      receiver.dead_letter_message(...)

  Maybe it is possible using azure.functions and azure.servicebus modules together?
  If so, adding documentation and examples would really help.
• It only works in C# ?
• In general, stating in the documentation which functionality is supported in which language would help as well.

Links:

• Converge azure.functions.ServiceBusMessage with azure.servicebus.ServiceBusMessage #1172
• Manually marking Service Bus Queue Function as Failed #1383
• https://learn.microsoft.com/en-us/answers/questions/1291520/how-to-control-the-message-when-azure-function-is
• Azure Service Bus bindings for Azure Functions
• Azure Service Bus output binding for Azure Functions#Example

Edit:
Batch processing is kinda impossible without being able to control what happens to individual messages. Without fine grained control we only have the option to retry the entire batch if something fails or not retry at all 😢

[vrdmr]

Hi @trin94 - We are working on SDK bindings for Service Bus (similar to the ones like Blobs), which will enable devs to do these updates.

We'll have more updates by next month but the current draft is available at feat: support ServiceBus SDK-type bindings, that'll target #1172 for now and more updates coming up.

It would be nice if the azure.functions service bus bindings add support (and documentation) for operations like abandoning and dead lettering.

Our goal is get the feature set eventually match the ones provided by ServiceBusMessageActions in C#.