How to combine the grouping aspect of Sessions with Batch receiving messages in an Azure Function

Othello Clemens 0

I have a use case where incoming servicebus messages need to be grouped by sessionId (the ordered processing is not really needed), where a function instance can receive a batch of messages of a session at the same time by using ServiceBusReceivedMessage[]. This can work but by doing so the concurrency of the sessions gets lost. User's image

Is there another feature that can provide the grouping aspect and has the concurrency that sessions can give me?

MayankBargali-MSFT 68,656 Reputation points

2024-02-28T10:25:04.0366667+00:00

@Othello Clemens Thanks for reaching out.

The session concept came when you needed to read the messages in the FIFO order for the same session. In case you don't need order of the session then is their specific requirement why you want to use the session enabled entity. If you don't need ordering, then you can create the non-session enable entities. For more details about why message sessions are used you can refer to this document.

In function service bus trigger if you are triggering on session enabled entity then the same instance will process all the session one a time but different session on the same entity can be process parallelly by the different instance of your function app. There is no configuration as it is not meant to be same session to be processed parallelly. It will one be processed one at a time.

You need to create a non-session enabled entity if you don't want to process the messages not in order.
Othello Clemens 0 Reputation points

2024-02-28T10:45:50.4666667+00:00

@MayankBargali-MSFT Thanks for your answer.

Like I mentioned in my post, i do not need the ordering requirement, but i need to ensure grouping of my messages while still keeping concurrency if i am using batching to receive multiple messages of the same "group" at the same time.
MayankBargali-MSFT 68,656 Reputation points

2024-02-28T10:57:44.8866667+00:00

@Othello Clemens Thanks for your response. If you could share more details why you need grouping or what you are trying to achieve finally from grouping, then I could think/suggest of alternative options in case if it is possible whether that would be possible from non-session entities with your custom business logic to track it.

To answer below question: Is there another feature that can provide the grouping aspect and has the concurrency that sessions can give me?

No there is no option to have concurrency with session enabled entities.
Othello Clemens 0 Reputation points

2024-02-28T12:08:19.03+00:00

@MayankBargali-MSFT My Function receives messages with contract info that has to be updated with the sessionId equal to the contractId, the messages with the same contractid need to be combined and this combination needs to be processed. If we only use batching then there can be instances where we update the same contract in parrallel instances of the function. This needs to be avoided.
MayankBargali-MSFT 68,656 Reputation points

2024-03-01T02:22:44.1066667+00:00

@Othello Clemens Thanks for sharing more details. Let me check if there could be any alternative way of achieving the same result or not.
Schneider, Michael 40 Reputation points

2024-04-25T14:25:40.1566667+00:00

@Othello Clemens @MayankBargali-MSFT Did you found any solution for your Scenario?