Azure Blob Trigger - Processing Timeout

Question

I'm looking to use a Blob Trigger for a long running processing of a file.

I'm aware there a processing timeouts durations for and have seen 5 minutes for Http trigger on consumption plan but can't find any documentation if there timeouts imposed for Blob triggers.

Answer 1

You can use functionTimeout attribute to schedule the timeout for Blob trigger Azure function.

Refer MSDOC to know more about functionTimeout.

• In Consumption Plan, Default Timeout is 5 Minuted and Maximum Timeout is 10 Minutes.

• For long running process that is more than 10 minutes, you can use Premium or App Service Plans.

• Set the functionTimeout in host.json as shown below:

{
"functionTimeout":"01:00:00"
}

I have created a Blob Trigger Azure function:

[FunctionName("Function")]
public void Run([BlobTrigger("myqueue-items/{name}", Connection = "demo")]Stream myBlob, string name, ILogger log)
{
    log.LogInformation($"C# Blob trigger function Processed blob\n Name:{name} \n Size: {myBlob.Length} Bytes");
    System.Threading.Thread.Sleep(30000);
}

• I'm let the function will sleep for 30 seconds by adding System.Threading.Thread.Sleep(30000); in the function code.

host.json:

I have scheduled the functionTimeout for 20 seconds.

{
  "version": "2.0",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "excludedTypes": "Request"
      },
      "enableLiveMetricsFilters": true
    }
  },
  "functionTimeout": "00:00:20"
}

I can see the function getting time out after 20 seconds.

• You can schedule the functionTimeout according to your requirement.

References:

https://github.com/Azure/Azure-Functions/issues/1900