I had the same thought as Stephen about the tablet splitting, but that wouldn't last for hours and hours unless your adding new data at a very high rate durring that time. Also, I'd expect the datastore viewer to not work correctly if your in code queries were failing because of that.
How do you get new data into the system? How many entities are you trying to fetch in a batch? What kind of changes are you making to these entities? When this problem is happening, is it just the one (query) task that is impacted or are other parts of your app impacted as well? If you insert a new version of that task does it run even though the other one keeps failing? Robert On Thu, May 26, 2011 at 03:50, Waleed Abdulla <[email protected]> wrote: > Thanks Stephen. Good point about the possibility of background splitting. > But then again, the app has been running for a year without problems, and > suddenly last week that query started to timeout. I didn't do any app > updates recently to cause this. > And when the query times-out, it tends to keep timing out again and again > for hours. So even if there is a background data re-organization happening, > it shouldn't keep the table unusable for hours like that. There must be > another explanation. > Waleed > > > > On Wed, May 25, 2011 at 2:43 PM, Stephen <[email protected]> wrote: >> >> On Wed, May 25, 2011 at 8:09 PM, Waleed Abdulla <[email protected]> wrote: >> > Stephen, >> > I don't see how your suggestion would help! Can you please elaborate >> > on >> > how it's related? >> >> This doesn't apply if you're not deleting, but deleted entities (and >> index entries) aren't deleted immediately but marked deleted and >> purged later. The dead index entries must be skipped over in queries >> before locating live entries. >> >> > Also, I'm not deleting any entities. I'm just updating >> > them. And when the query is timing out, it does so even when there is no >> > load on the app. >> >> So perhaps a high rate of inserts/updates on your monotonically >> increasing eta index is overloading a tablet server and causing >> frequent splitting? I guess it might not always correspond directly >> with traffic to the app as the datastore schedules the rearranging. >> >> If you do have a high update rate, maybe try to aggressively batch >> them into large transactions? >> >> -- >> 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. > -- 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.
