The reason I ask is if you're using Java, could you perhaps being opening a persistence manager in your instances that aren't being closed for each request and thus getting cached data in those instances by it?
On Mon, Nov 22, 2010 at 11:54 AM, Stephen Johnson <[email protected]>wrote: > What platform? Java or Python? > > > On Mon, Nov 22, 2010 at 11:03 AM, Alfred Fuller < > [email protected] <arfuller%[email protected]>> wrote: > >> This sound like what would happen if read_policy=EVENTUAL_CONSISTENCY is >> enabled. Are you setting this anywhere? >> >> >> On Fri, Nov 19, 2010 at 9:37 AM, Sanjay <[email protected]> wrote: >> >>> I'm pretty sure the data consistency is not in our application because >>> of the characteristics of the problem. I do not use Memcache or a per- >>> instance in-memory cache, and perform direct reads from the datastore >>> as the application is high-write, low-read. >>> >>> I can reproduce this problem at will by just refreshing a page that >>> reloads the data from the datastore. About 20% of the time I get an >>> incorrect value. The data is being written using a cron that fires >>> every 10 minutes, and there are no other writers to this entry. Thus >>> I'm pretty sure that it's not being performed by an incorrect write. >>> From the characteristics, it seems to me like there's an instance >>> serving the application that is stale and serving bad data. Perhaps >>> this instance is in a different datacenter than the main set of >>> instances, and thus Megastore replication has fallen behind, or is in >>> an inconsistent state? >>> >>> I've been working with AppEngine for nearly the last year, and haven't >>> seen this bizarre behavior before. >>> >>> Is there a way to escalate such issues for someone in Google to have a >>> look? >>> >>> Thanks! >>> >>> On Nov 19, 8:31 am, Robert Kluin <[email protected]> wrote: >>> > I did not see anything quite like that. It sort of sounds like you >>> > might have a cache bug. Perhaps instance variables are being used as >>> > cache? >>> > >>> > Robert >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > On Fri, Nov 19, 2010 at 04:04, Sanjay <[email protected]> wrote: >>> > > Hello, >>> > >>> > > Starting earlier today around the time of the App Engine deploy >>> > > outage, I'm seeing a lot of data inconsistency. Data written several >>> > > minutes earlier cannot be read back consistently. Even more >>> > > surprisingly, just retrying the operation multiple times yields older >>> > > versions of the same data. Is anyone else seeing this? >>> > >>> > > Thanks, >>> > > Sanjay >>> > >>> > > -- >>> > > 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]<google-appengine%[email protected]> >>> . >>> > > For more options, visit this group athttp:// >>> 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]<google-appengine%[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]<google-appengine%[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.
