Azure Blob Trigger function app : running same instance for multiple blobs upload

Question

I have created a Blob triggered function app in Python. My requirement is to run a separate instance for each blob upload (for parallel processing), but it's not happening. Even I have modified the host.json as below as per the below link: https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-blob

{ "version": "2.0", "extensions": { "blobs": { "maxDegreeOfParallelism": "4" } } }

Still, the same instance is running and processing files one by one. Am I missing something here?

Answer 1

I'm afraid we can't implement this requirement. As far as I know, we can just set the function app to scale out to maximum n(in your case is 4) instances, but we can't scale out instances manaually.

When you modify the configuration to allow the function app to scale out for multiple instances, it can just scale out automatically when lots of requests coming. If there are only 4 request, only one instance will be started in most cases.

Here is another post I did research in the past which is similar problem with this case for your reference.