I am getting <class 'google.appengine.runtime.DeadlineExceededError'>
On Dec 18, 12:12 pm, Marzia Niccolai <[email protected]> wrote: > Hi Derrick, > > What DeadlineExceedError message are you getting, there are a few different > deadlines you can run in to with App Engine. > > The most common would be the request deadline. Any given request with App > Engine must be completed within 10 seconds. This is the runtime > DeadlineExceededError > > Various APIs, like the datastore and URLFetch also have deadlines to ensure > that those calls return within the overall request deadline. If you are > running in to this deadline, you will get the > apiproxy_errors.DeadlineExceededError. > > The problem shouldn't have anything to do with indexing, since simple > queries indexes are automatically generated, there is no need specify them > in the index.yaml (see this > article:http://code.google.com/appengine/articles/index_building.html) > > From your description I can imagine the problem is either you are requesting > too much information from the datastore (running in to > apiproxy_errors.DeadlineExceededError) in one request. The amount of data > you can return in a query will depend on the size and shape of your data, > but you can test this by reducing the amount of data you query for in one > call. > > The other issue I can see is that you are just taking too long to return the > entire request. This probably happens because it takes too long to process > all of your results before the request deadline. > > Generally in such a case we'd suggest profiling your application which will > indicate on which calls, and for how long, your app spends it's time. Some > good information on profiling can be found in our > FAQ:http://code.google.com/appengine/kb/commontasks.html#profiling > Screencast: > Optimizing Your App: Profiling and > Memcachehttp://www.youtube.com/watch?v=Zip1G6-NiMM > And the Google I/O talk 'Building a Production Quality Application on Google > App > Engine:http://sites.google.com/site/io/best-practices---building-a-productio... > > -Marzia > > On Thu, Dec 18, 2008 at 10:39 AM, Derrick <[email protected]> wrote: > > > I am consistently getting Deadline exceeded messages. The problem is > > that my individual requests are trivial: do a query or two to > > BigTable, serialize the results, and return them. > > > So, what could be causing these messages. How are deadlines actually > > measured on app engine? > > > In my case, I am sending a number (10-50) of requests in parallel. > > Each individual request retrieves a single row in a table plus one or > > two rows in related tables. > > > I would guess that that CPU time usage is measured by interrupting the > > thread serving a request at regular intervals. The question is, how > > does this interrupt ascertain whether a CPU deadline has been > > exceeded. > > > I hypothesize that when the poller wakes up, it checks to see which > > application has the cpu, and adds a tick to the count for that user. > > If the same application is using the CPU as the previous time the > > poller awoke, then the poller checks to see if the tick count exceeds > > the deadline. If so, it initiates a deadline exceeded message and > > terminates the request. > > > If this is the algorithm, then it is very problematic for me. Will > > someone from the Google App Engine team explain to us the workings of > > the Deadline measuring algorithm so that we can adjust our application > > for work on the platform. > > > Also, could the problem have anything to do with indexing? Our > > queries are dirt simple: a single query parameter, so we do not > > generate indices for them manually. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
