Azure function not triggered by blob events

Question

I have a azure function created with ARM Template by using powershell.

Function is blobtrigger type function running on consumption plan, to copy blob from source storage to destination storage.

When I upload blob to source storage it will not copied. That means function is not executed.

When I browse function app through portal, function get invoked and do the required things as expected. Thereafter it works fine. It only happens when function app initially deployed by powershell script using ARM templates.

So I guess Issue is, when I create function app using ARM template and deployed using powershell it is in idle mode, and never triggered by blob events. Is my assumption correct or could you please help me to find the issue. Thanks.

Answer 1

Be careful here. According to the Blob Storage Documentation it mentions that there may be a delay for this trigger if on the consumption plan: (emphasis mine)

When your function app runs in the default Consumption plan, there may be a delay of up to several minutes between the blob being added or updated and the function being triggered. If you need low latency in your blob triggered functions, consider running your function app in an App Service plan.

Perhaps the behavior you are seeing is a manifestation of the above. Try converting to an App Service Plan and see if you still see the delay in the trigger.

I suspect it has nothing to do with your deployment method.