Ikai, We see daily DeadlineExceededErrors on app id 'steprep' from 6.30am to 7.30am (log time).
Can you look into that as well? Thanks, j On Dec 14, 3:32 pm, "Ikai L (Google)" <ika...@google.com> wrote: > Do you see that it's consistent at the same times? What's your application > ID? I'll look into it. > > > > > > On Mon, Dec 14, 2009 at 11:28 AM, Dave Peck <davep...@gmail.com> wrote: > > Hello, > > > I have an app (citygoround.org) that, especially in the morning, often > > has 10-15 minutes of outright downtime due to server errors. > > > Looking into it, I see that right before the downtime starts, a few > > requests log the following warning message: > > > > Request was aborted after waiting too long to attempt to service > > your request. > > > Most likely, this indicates that you have reached your > > simultaneous dynamic request limit. > > > I'm certainly not over my limit, but I can believe that the request in > > question could take a while. (I'll get to the details of that request > > in a moment.) > > > Immediately after these warnings, my app has a large amount of time > > (10+ minutes) where *all requests* -- no matter how unthreatening -- > > raise a DeadlineExceededError. Usually this is raised during the > > import of an innocuous module like "re" or "time" or perhaps a Django > > 1.1 module. (We use use_library.) > > > My best theory at the moment is that: > > > 1. It's a cold start, so nothing is cached. > > 2. App Engine encounters the high latency request and bails. > > 3. We probably inadvertently catch the DeadlineExceededError, so the > > runtime doesn't clean up properly. > > 4. Future requests are left in a busted state. > > > Does this sound at all reasonable? I see a few related issues (2396, > > 2266, and 1409) but no firm/completely clear discussion of what's > > happening in any of them. > > > Thanks, > > Dave > > > PS: > > > The specifics about our high latency request are *not* strictly > > relevant to the larger problem I'm having, but I will include them > > because I have a second "side" question to ask about it. > > > The "high latency" request is serving an image. Our app lets users > > upload images and we store them in the data store. When serving an > > image, our handler: > > > 1. Checks to see if the bytes for the image are in memcache, and if so > > returns them immediately. > > 2. Otherwise grabs the image from the datastore, and if it is smaller > > than 64K, adds the bytes to the memcache > > 3. Returns the result > > > I'm wondering if using memcache in this way is a smart idea -- it may > > very well be the cause of our latency issues. It's hard to tell. > > > Alternatively, the issue could be: we have a page that shows a large > > number (~100) of such images. If someone requests this page, we may > > have a lot of simultaneous image-producing requests happening at the > > same time. Perhaps _this_ is the root cause of the original "Request > > was aborted" issue? > > > Just not sure here... > > > -- > > > 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<google-appengine%2Bunsubscrib > > e...@googlegroups.com> > > . > > For more options, visit this group at > >http://groups.google.com/group/google-appengine?hl=en. > > -- > Ikai Lan > Developer Programs Engineer, Google App Engine -- 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.
