QueueTrigger Attribute Visibility Timeout

问题

If I were to get a message from queue using Azure.Storage.Queue

queue.GetMessage(TimeSpan.FromMinutes(20));

I can set the visibility timeout, however when trying to use Azure.WebJobs (SDK 0.4.0-beta) attributes to auto bind a webjob to a queue

i.e.

public static void ProcessQueueMessage([QueueTrigger("myqueue")] string message){
       //do something with queue item
}

Is there a way to set the visibility timeout on the attribute? There does not seem to be an option in JobHostConfiguration().Queues. If there is no way to override, is it the standard 30 seconds then?

回答1:

In the latest v1.1.0 release, you can now control the visibility timeout by registering your own custom QueueProcessor instances via JobHostConfiguration.Queues.QueueProcessorFactory. This allows you to control advanced message processing behavior globally or per queue/function.

For example, to set the visibility for failed messages, you can override ReleaseMessageAsync as follows:

protected override async Task ReleaseMessageAsync(CloudQueueMessage message, FunctionResult result, TimeSpan visibilityTimeout, CancellationToken cancellationToken)
{
    // demonstrates how visibility timeout for failed messages can be customized
    // the logic here could implement exponential backoff, etc.
    visibilityTimeout = TimeSpan.FromSeconds(message.DequeueCount);

    await base.ReleaseMessageAsync(message, result, visibilityTimeout, cancellationToken);
}

More details can be found in the release notes here.

回答2:

I have the same question and haven't found answer yet. But, to answer a part of your question, the default lease is 10 minutes.

Quoting the Azure Website: "When the method completes, the queue message is deleted. If the method fails before completing, the queue message is not deleted; after a 10-minute lease expires, the message is released to be picked up again and processed. This sequence won't be repeated indefinitely if a message always causes an exception. After 5 unsuccessful attempts to process a message, the message is moved to a queue named {queuename}-poison. The maximum number of attempts is configurable."

Link: http://azure.microsoft.com/en-us/documentation/articles/websites-dotnet-webjobs-sdk-get-started/ Section: ContosoAdsWebJob - Functions.cs - GenerateThumbnail method

Hope this helps!

来源：https://stackoverflow.com/questions/26937782/queuetrigger-attribute-visibility-timeout