Graceful cancellation period on function timeout

[dmytro-gokun]

Description

When a function call is being cancelled because of the execution timeout, it does not seem that the CancellationToken passed to it being signaled. Instead, the function app simply exits. Would not it make more sense if the timeout-related shutdown was performed in a bit more 'graceful' way, i.e. CancellationToken signaled and some (configurable) graceful shutdown period allowed (e.g. 10 sec by default)?

[liliankasem]

Hi @dmytro-gokun, a cancellation token should be getting signaled on function timeout, I believe there a graceful shutdown period of a couple seconds but is not configurable.

Can you share more details about the issue you're seeing? If you're able to share a region, timestamp and invocation ID I should be able to investigate further. Thanks!

[dmytro-gokun]

@liliankasem I did some testing and I think you are right about CancellationToken and 2 second timeout. The reason i thought cancellation token was not signaled is that i have code like this:

    public class Function
    {
        [Function("Function")]
        public async Task Run(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] 
            HttpRequestData request,
            CancellationToken cancellationToken)
        {
            try
            {
                await DoWork(cancellationToken);
            }
            catch (OperationCanceledException)
            {
                Log.LogInformation("Canceled");
            }
        }
    }

with logs being set to Application Insights. So, that "Canceled" log does not end up in AI. I think the reason for that is that the worker gets restarted after the function timeout and some AI logs are lost. Not 100% sure about this though...

[liliankasem]

If the issue is with AppInsights ingestion then I think we can track these issues in your other GH issue and close this one?

• AI logs are not flushed when process exits #2379

[dmytro-gokun]

Agree