Behavior of TerminateAsync

[lilyjma]

I have this code:

        [FunctionName("lilyDotnetDFTest_HttpStart")]
        public static async Task<HttpResponseMessage> HttpStart(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequestMessage req,
            [DurableClient] IDurableOrchestrationClient starter,
            ILogger log)
        {
            // Function input comes from the request content.
            string instanceId = await starter.StartNewAsync("lilyDotnetDFTest", null);

            log.LogInformation($"Started orchestration with ID = '{instanceId}'.");

            await starter.TerminateAsync(instanceId, "testing termination");

            return starter.CreateCheckStatusResponse(req, instanceId);
        }

I went to the statusQueryGetUri url and saw that the runtime status is terminated. However, on Azure Portal, I still see the orchestration as running:

Orchestration details show that the orchestration was terminated, but then started

@davidmrdavid explained that this is because TerminateAsync terminates running orchestrations, not scheduled ones. What the code above does is schedule an orchestration, then immediately terminates it. But at that point, there's no orchestration running yet, so there's nothing to terminate. And so what was originally scheduled would still run. Is this the expected behavior? How would I cancel a scheduled orchestration then?

[cgillum]

@lilyjma I suspect you hit some kind of race condition where the "start" and "terminate" messages are racing with each other. I don't think it's very common for people to start and then terminate their orchestration in the same function, so I assume not many people run into this. It is odd, however, that the runtime status you get from statusQueryGetUri shows Terminated even though the orchestration appears to have run.

What happens if you put an await Task.Delay(TimeSpan.FromSeconds(5)); between the start and terminate calls of your function?

[lilyjma]

Apologies for the late response.

I did what you instructed and for the specific orchestration instance, I got terminated in statusQueryGetUri, runtime status as running in orchestration trace, and awaited (after terminated) in orchestration trace detail

[davidmrdavid]

I've added an item on our taskboard (in backlog) to track an investigation for this.