We can say unequivocally that under high load, if you have a transaction around a task enqueue without any database calls, you will get the ConcurrentModificationException error.
This is how the Pipeline library is setup for FINALIZE_JOB. If you need to implement this pattern, then I would create a non-sense database call to see if that will work...we didn't need to make a database call so we took it out of the transaction, but the code that did have database operations and task enqueues within the transaction did not have this error. On Saturday, June 16, 2012 4:44:29 PM UTC-4, Michael Hermus wrote: > > I just saw the issue pop up again, so it appears that (as you correctly > predicted) Objectify had nothing to do with the issue. > > Sigh... I am not sure how to approach a resolution for this, because my > app makes significant use of this pattern. Do I perhaps need to store at > least one entity with each transaction in order to avoid this? > > On Tuesday, June 12, 2012 3:20:43 PM UTC-4, Michael Hermus wrote: >> >> Jeff, >> >> I haven't seen the problem since I made the change, and it seemed >> consistent under certain circumstances before that point. However, I have >> relatively few data points, so I wouldn't call it conclusive. If I have >> time, I will switch the transaction back to Objectify and see if that >> causes the issue to crop up again. >> >> Mike >> >> On Monday, June 11, 2012 7:20:08 PM UTC-4, Jeff Schnitzer wrote: >>> >>> Ah, sorry that wasn't clear to me. >>> >>> I'm not sure how the presence of Objectify in this chain could make >>> any difference. There's nothing special about the way Objectify >>> starts or commits a transaction. Was this behavior consistent? >>> >>> Jeff >>> >>> -- 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/-/jdreH4oxnLwJ. 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.
