Can I run some code in a WebJob after the timeout has been reached?

Question

I have a continuos WebJob using the ServiceBusTrigger. I also set a timeout of 10 minutes. If the function finishes before, it sends a response to another queue.

But in case of a timeout, it just exits. Is it possible to run some code when timeout is reached? Like a callback function. So I can send a proper message that the process timed out.

    [Timeout("00:10:00")]
    public static async Task ProcessPreflightQueueMessage([ServiceBusTrigger("%preflightQueue%")] string message, CancellationToken token, ILogger logger)
    { ... }

Answer 1

Yes you could, while the function timeout, it will throw TaskCanceledException, you could catch it and do your stuff.

Here is my test.

public class Functions
{
    [Timeout("00:00:30")]
    public static async Task TimeoutJob(
        [QueueTrigger("myqueue")] string message,
        CancellationToken token,
        TextWriter log)
    {

        try
        {
            await log.WriteLineAsync(message);
            log.WriteLine($"-- [{DateTime.Now.ToString()}] Processing Begin --");
            await Task.Delay(TimeSpan.FromMinutes(1), token);
            log.WriteLine($"-- [{DateTime.Now.ToString()}] Complete Time-consuming jobs --");
        }
        catch (TaskCanceledException)
        {
            log.WriteLine("timeout");
        }
        log.WriteLine($"-- [{DateTime.Now.ToString()}] Processing End -- ");
    }

}