We have a HttpTrigger Azure function app and this is calling a durable function. This durable function is returning a HttpResponseData after calling the CreateCheckStatusResponseAsync.

We weren't able to create a custom response and getting the response from CreateCheckStatusResponseAsync only.

Please advice how to customise this response.

This is the sample code:

// Function app
[Function("HelloCities_HttpStart")]
public static async Task<HttpResponseData> HttpStart([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequestData req,
        [DurableClient] DurableTaskClient client,
        FunctionContext executionContext)
{
    ILogger logger = executionContext.GetLogger("HelloCities_HttpStart");

    // Function input comes from the request content.
    string instanceId = await client.ScheduleNewOrchestrationInstanceAsync(nameof(HelloCities));

    logger.LogInformation("Started orchestration with ID = '{instanceId}'.", instanceId);

    // Returns an HTTP 202 response with an instance management payload.
    // See 
    return await client.CreateCheckStatusResponseAsync(req, instanceId);
}

The response that we are expecting should be like this:

But the response we are getting instead is:

We have a HttpTrigger Azure function app and this is calling a durable function. This durable function is returning a HttpResponseData after calling the CreateCheckStatusResponseAsync.

We weren't able to create a custom response and getting the response from CreateCheckStatusResponseAsync only.

Please advice how to customise this response.

This is the sample code:

// Function app
[Function("HelloCities_HttpStart")]
public static async Task<HttpResponseData> HttpStart([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequestData req,
        [DurableClient] DurableTaskClient client,
        FunctionContext executionContext)
{
    ILogger logger = executionContext.GetLogger("HelloCities_HttpStart");

    // Function input comes from the request content.
    string instanceId = await client.ScheduleNewOrchestrationInstanceAsync(nameof(HelloCities));

    logger.LogInformation("Started orchestration with ID = '{instanceId}'.", instanceId);

    // Returns an HTTP 202 response with an instance management payload.
    // See https://learn.microsoft/azure/azure-functions/durable/durable-functions-http-api#start-orchestration
    return await client.CreateCheckStatusResponseAsync(req, instanceId);
}

The response that we are expecting should be like this:

But the response we are getting instead is:

• c#
• azure
• azure-functions

1 Answer 1

When you call await client.ScheduleNewOrchestrationInstanceAsync it's only scheduling the Orchestration to start. That will take a finite amount of time.

Meanwhile, you immediately proceed to checking the Orchestration status, even though it probably hasn't had time to start yet.

There are a few solutions.

1. Not very elegant: add a Task.Delay of a few seconds after scheduling the Orchestration, to allow time for it to start. This is pretty bad, because there's no guarantee how long you need to wait so it will sometimes fail; and it will slow your HTTP request.

2. Better: make your Function return a 202 Accepted response^1 with another URL (another Function) that they can call to check the status of the Orchestration, and move that code into there.