Thanks for the suggestions. It's not an eventual consistency issue, and I get datastore timeout exceptions so there can't be a blind try- except. The code does a put() for one or more entities inside run_in_transaction(), then does a raw put() for another entity. Here's the simplified code:
logItems='' for id in ids: db.run_in_transaction(updateEntity,id,newTime) logItems+=rh.logItem('B',newTime) entity2.log+=logItems entity2.put() The put() in updateEntity() works, the entity2 put() fails without an exception. The only reason I know this is that when I compare the log data in entity2 it doesn't match the data in the updated entities. This only happens once per 10,000 times, and I was lucky to catch two recent cases - the time logged by the successful updateEntity() call corresponding to the missing entity2 entry exactly matches the "Transaction collision. Retying..." warning in the logs in both cases. There are a few questions this raises: 1. I have assumed that the "Transaction collision. Retying..." warning is caused by the updateEntity(), because it's in a run_in_transaction(). But given the entity2.put() is the one failing, perhaps that is the source? Can you get transaction collision warnings from non-transactional put()s? 2. Surely no matter what I should get an exception if the entity2.put() fails? Thanks again for your help with this. Greg. On Jul 8, 2:51 am, Robert Kluin <robert.kl...@gmail.com> wrote: > Hey Greg, > Do you have any blind try-excepts in your code? If it is silently > failing, I'd guess something issilently catching and ignoring the > exception. > > Also, as Noah mentioned, a global query immediately after a put > might not get the latest results. A get-by-key or ancestor query > will. > > Robert > > > > > > > > > > On Wednesday, July 6, 2011, Greg <g.fawc...@gmail.com> wrote: > > Hi - > > > I've just discovered that occasionally put()s in my python HR > > datastore app are failing almost silently. "Almost" because I am > > seeing a "Transaction collision. Retying..." warning logged at the > > time the write is supposed to happen, but nothing else - certainly no > > exception is raised. > > > This is severely impacting the integrity of my data. I'm currently > > running a remote checking script daily to fix the data, but this is a > > horrible band-aid and should not be required. Either the put() should > > succeed, or an exception should be raised. > > > Any ideas? > > > Cheers > > Greg. > > > -- > > You received this message because you are subscribed to the Google Groups > > "Google App Engine" group. > > To post to this group, send email to google-appengine@googlegroups.com. > > To unsubscribe from this group, send email to > > google-appengine+unsubscr...@googlegroups.com. > > For more options, visit this group > > athttp://groups.google.com/group/google-appengine?hl=en. > > -- > ------ > Robert Kluin > Ezox Systems, LLC -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.