The tasks can be run out-of-order (relative to how they were inserted). The marker number is used to identify and discard 'stale' updates, so if the aggregation already contains the information at state 18, when the information from state 17 arrives it will be skipped.
Robert On Fri, Mar 11, 2011 at 12:24, Lucas <[email protected]> wrote: > 1.let say student is updated and marker is incremented from 16 to > 17 . 2 tasks are fired call taskA, and taskB > 2. then student is update again and market is incremented from 17 to > 18. another 2 tasks are fired call task C, and task D. > Is there any gurantee task set (A, B) will be execute before task set > (C, D) ? because task queue wiki mentioned there is no guarantee for > the sequence of execution . if this ordering is not gurantee, in mean > in high load side, if task C and D are executed before task A, B. > data consistency has problem. > Is this the reason, in Brett''s talk, he suggested do transaction 1/ > second to minimize this from happening? > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > 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. > > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. 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.
