I think i solved the problem. The Entry.exists call was inside an async urlfetch callback. I had this : http://groups.google.com/group/google-appengine-python/browse_thread/thread/0230d030d8407de7 problem with Datastore puts inside callbacks. But the gets seemed to work because they didnt raise any Exceptions, instead they were returning inconsistent results. It got fixed when i rearranged some of the stuff so that the put can be done outside callback.
On Dec 19, 10:04 am, johnP <j...@thinkwave.com> wrote: > z33m - just looked at your thread, and see that the query in question > is similar to > info = cls.all().get() > > My situation was similar. Before allowing a person to be deleted, I > check if the person has any data, by doing something similar to: > has_data = person.data_set.get() > if has_data: > return error message saying clear data before deleting > else: > delete person > > So one case was where a person got deleted, but there was data. > Understood - there can be something in my code. But after tracing the > logs, speaking with the user to be sure he acted as expected, and > looking carefully enough to be pretty sure that the code is generally > OK led me to a preliminary conclusion to wait and see if something > similar reoccurs. btw - this incident occurred pretty close to an > Appengine deployment period. > > In general, these kinds of cases are fairly rare. And experience > shows that whenever I'm sure that the datastore's at fault, I > eventually find the real bug in my code :) > > johnP > > On Dec 18, 7:32 pm, z33m <mailsforaz...@gmail.com> wrote: > > > > > This is actually not the first time for me either. I've had a similar > > problem some months back > > :http://groups.google.com/group/google-appengine/browse_thread/thread/... > > . Not sure if they are related or not. But in either case the > > Datastore seemed to return inconsistent data. > > > On Dec 19, 1:24 am, johnP <j...@thinkwave.com> wrote: > > > > That's an interesting question. I've had two or three instances in > > > the past few months where *it appeared* that a query returned None > > > when it should have returned something (or an error, at least). I'm > > > not sure if this was the case, and do not claim it to be the case:) > > > But in analyzing chains of events, it seemed that this could have been > > > the root cause for certain situations. > > > > That's why I too am interested the answer to this question. > > > > johnP > > > > On Dec 18, 12:05 pm, z33m <mailsforaz...@gmail.com> wrote: > > > > > Hi, > > > > > Im writing a simple feed crawler using tasks. Feed entries are stored > > > > in Entry model. I use guids to check whether an entry exists or not, > > > > to avoid entries from begin crawled more than once.. But my checking > > > > mechanism seems to be failing.. > > > > > Here is the check function and Entry model that i use.. > > > > > class Entry(db.Model): > > > > guid = db.StringProperty() > > > > title = db.TextProperty() > > > > > @classmethod > > > > def exists(cls, guid): > > > > query = db.Query(cls, keys_only = True) > > > > key = query.filter('guid =', guid).get() > > > > if key: > > > > logging.info('True : %s' % guid) > > > > return True > > > > else: > > > > logging.info('False : %s' % guid) > > > > return False > > > > > and i get strange logs like this > > > > > I 12-18 11:29AM 06.720 True :http://www.techcrunch.com/?p=129969 > > > > I 12-18 11:29AM 06.721 False :http://www.techcrunch.com/?p=129937 > > > > I 12-18 11:29AM 06.722 False :http://www.techcrunch.com/?p=129963 > > > > I 12-18 11:29AM 06.723 False :http://www.techcrunch.com/?p=129883 > > > > .... all other entries are False .... > > > > > I 12-18 11:19AM 00.745 True :http://www.techcrunch.com/?p=129969 > > > > I 12-18 11:19AM 00.754 True :http://www.techcrunch.com/?p=129937 > > > > I 12-18 11:19AM 00.763 True :http://www.techcrunch.com/?p=129963 > > > > I 12-18 11:19AM 00.770 True :http://www.techcrunch.com/?p=129883 > > > > .... all other entries are True .... > > > > > am i doing something wrong? .. how is it possible that the same query > > > > that returned a key 10min ago return None now? -- 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-appeng...@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.
