Would like more control over scaling durable functions

Would be great if we could have more control over how azure functions scale when the performance of running a fanout orchestration is important.

See this post

Would be great if we could have something like this, rough and would need much more thought but something along these lines.

 var activityBatchRequest = new DurableFunctionBatchRequest<TResult>
            {
                ActivityName = "ComputeItems",
                ApproximateCpuTimePerActivity = new TimeSpan(0, 0, 0, 10),
                RequestedExecutionTime = new TimeSpan(0, 0, 0, 20),
                Activities = activities
            };
            var tasks = orchestrationContext.CallActivityBatchAsync<IEnumerable<TResult>(activityBatchRequest);

This way Azure could calculate roughly how many vm’s to scale out to so it can attempt to meet the users request time

[BenjaBobs]

@ianadavies

Hi, after poking around a bit I found that you can achieve some control with a Premium Plan.

By sending the following requests you can control the following. Note: It requires the Contributor role for plan and the functions app respectively

Instance Count:

PATCH https://management.azure.com/subscriptions/<subscriptionId>/resourceGroups/<resourceGroupName>/providers/Microsoft.Web/serverfarms/<premiumPlanName>?api-version=2018-11-01
Authorization: <bearer token>
Content-Type: application/json

{
    "id": "/subscriptions/<subscriptionId>/resourceGroups/<resourceGroupName>/providers/Microsoft.Web/serverfarms/<premiumPlanName>",
    "kind": "elastic",
    "location": "<location>",
    "name": "<premiumPlanName>",
    "properties": {
        "numberOfWorkers": 20, 
    },
    "sku": {
        "capacity": 20, 
    },
}

Pre-warmed instance count:

PATCH https://management.azure.com/subscriptions/<subscriptionId>/resourceGroups/<resourceGroupName>/providers/Microsoft.Web/sites/<functionsAppName>/config/web?api-version=2018-11-01
Authorization: <bearer token>
Content-Type: application/json

{
    "id": "/<subscriptionId>/resourceGroups/<resourceGroupName>/providers/Microsoft.Web/sites/<functionsAppName>/config/web",
    "name": "<functionsAppName>",
    "type": "Microsoft.Web/sites/config",
    "location": "<location>",
    "properties": {
        "reservedInstanceCount": 20,
        "functionsRuntimeScaleMonitoringEnabled": false
    }
}

It doesn’t help you much if you’re still set on Consumption Plan though.

[ianadavies]

@cgillum You mentioned here that you had plans to make this possible later this year. Any news on this?

I have opened this ticket on StackOverflow https://stackoverflow.com/questions/51657553/azure-durable-functions-scaling/51659347

This is becoming a real problem for us now as we are ready to demo our software to potential clients and I was expecting to be able to scale to 200 nodes since the consumption plan supported this.

Is there anyway we can connect and show you the problems we are having ?

Thanks