Agree with John, we see spurious duplicate tasks with about the same rate. We also leverage datastore transactions as the ultimate semaphore to ensure that we don't execute multiply (in our case, we just have a model with no attributes using the taskname as the key name; in a transaction we just make sure we haven't already seen the task then write the new key down if not).
BTW, we use our open source Fantasm (code.google.com/p/fantasm) to perform this gate check automatically. j On Thursday, 27 December 2012 14:42:55 UTC-6, Mahron wrote: > > Thanks for your insight and stats. > > The tasks are either idempotent or multiple execution is acceptable up > to a certain point. > > But if two workers can be returned the same tasks if called > simultaneously(in normal conditions), then I have a problem, as > multiple execution would happen far too often. According to the doc I > assume it is not suppose to happen but I would like to have > confirmation. > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/T12uOztHbK8J. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
