Queue Azure Function Processing Queue Items Simultaneously

Question

Hello,

I created a Queue and an Azure Function with a queue trigger and it's all working perfectly. 

What I'm noticing though from my logs is that if I quickly add 10 items to the queue, it seems as if the Azure Function will process them all at the same time.  I was hoping this would actually process them 1 at a time so that once the first item is de-queued it processes it, then de-queues the second one.  I think what's happening is it's picking up all 10 and then running them simultaneously.

Does anyone know if this is accurate or if there is a way to process the one at a time?

Thanks

Answer 1

Hi, I think if you have to process one at a time, you should probably use an durable functions. You can probably use an activity function to do the job and orchestrator to call that sequentially. Or probably use a timer triggered function to try it to do sequentially. Others can add if there are better approach to do it.

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Sujith

Answer 2

You can try to set batchSize property in host.json to 1. Details:

https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-queue#trigger---concurrency

Alexey

Answer 3

Thanks Alexey, this works!