App Engine - Task Queue Retry Count with Mapper API

问题

here is what I'm trying to do: I set up a MapReduce job with the new Mapper API. This basically works fine. The problem is that the Task Queue retries all tasks that have failed. But actually I don't want him to do that. Is there a way to delete a task from the queue or tell it that the task was completed successfully? Perhaps passing a 200 status code?

I know that I can fetch the X-Appengine-Taskretrycount, but that doesn't really help since I don't know how to stop the task. I tried using a 'pass' in the try .. except block but that didn't work either.

Any help would be much appreciated :)

Thanks, Chris

回答1:

In your task handler do this

class yourTaskWorker(webapp.RequestHandler):
    def post(self):
        logging.info('yourTaskWorker (post)...')        
        if int(self.request.headers['X-Appengine-Taskretrycount']) == 0:
            logging.info('running task...')
            # call whatever functions you want here
        else:
            logging.info('this task failed before, not going to retry.')
            # obviously call nothing here, the task will "pass" without error and go away

Hope this helps!!

回答2:

As of http://code.google.com/p/appengine-mapreduce/source/detail?r=114 change, context object has task_retry_count attribute.

来源：https://stackoverflow.com/questions/3342072/app-engine-task-queue-retry-count-with-mapper-api