Can we prioritise one function over another in an Azure Function App

Question

Having the Azure function (.NET Core 6) with service bus queues (2 queues) where there is a trigger function code for each queue.

Seen a issue in the GitHub which shown me that functions will be processed in Alphabetical order.

Instead of processing alphabetical order, I like to do custom order like

1. Specified function trigger should be processed as first even both triggers are waiting for messages

Is that possible to prioritize explicitly like above scenario?

Answer 1

Hi @NFSCoder-9821 ,

Thanks for posting this question in Q&A forum.

The scenario that you want to achieve is called competing consumers and there is a dedicated design pattern called competing consumers pattern. However there is a limitation with the messaging order with this pattern. The order in which consumer service instances receive messages isn't guaranteed, and doesn't necessarily reflect the order in which the messages were created.
So it is not possible to prioritize one function over another listening to the service bus queue unfortunately.

With Durable functions, you can control the orchestrator and activity function but not the starter function, your scenario involves starter function so durable functions wont help in this case.

I hope this helps! Feel free to reach out to me if you have any further queries or concerns.

Answer 2

As far as I know, unfortunately, it's not possible at the moment.

Answer 3

to control the order, use durable functions

https://learn.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-orchestrations?tabs=csharp