HttpClient async requests not completing for large batch sent out in a loop

Question

I think I\'ve managed to make a test that shows this problem repeatably, at least on my system. This question relates to HttpClient being used for a bad endpoint (no

Answer 1

I looked through the source of HttpClient using reflector. For the synchronously executed part of the operation (when it is kicked-off), there seems to be no timeout applied to the returned task, as far as I can see. There is some timeout implementation that calls Abort() on an HttpWebRequest object, but again they seem to have missed out any timeout cancellation or faulting of the returned task on this side of the async function. There maybe something on the callback side, but sometimes the callback is probably "going missing", leading to the returned Task never completing.

I posted a question asking how to add a timeout to any Task, and an answerer gave this very nice solution (here as an extension method):

public static Task WithTimeout(this Task task, TimeSpan timeout)
{
    var delay = task.ContinueWith(t => t.Result
        , new CancellationTokenSource(timeout).Token);
    return Task.WhenAny(task, delay).Unwrap();
}

So, calling HttpClient like this should prevent any "Tasks gone bad" from never ending:

Task _response = httpClient.PostAsJsonAsync