Are you implying that the GAE DAL could profit from new exceptions for BigTableDownForMaintenance & BigTableTimeOut?
On Sep 19, 11:12 am, Robin B <robi...@gmail.com> wrote: > The GAE DAL does not try to handle the 1000 fetch limit. GAE apps > must be designed differently, meaning if you need more than 1000 > results from a query, then probably what you were attempting to do is > not scalable. Queries are O(#results), so you should keep your > queries small to make your requests fast. > > Web requests should return results not compute results. > > To compute results, you should use the 'appengine task queue' to > register webhook call-backs to perform aggregation offline like a map- > reduce job. Then web requests are quick and just serve a short list > of answers. > > As far as maturity, the GAE DAL driver has been used in production for > over a year in its current form, so it is stable. Since then, Google > has added a Capability API, so you can now tell if the DB is in read- > only (maintenance) mode before attempting writes, which means you > could return a nice maintenance mode message to your users instead of > failing. Also the GAE datastore can sometimes throw spurious > 'Datastore Timeout Exceptions' which could be caught and then could > attempt exponential backoff and retry. > > Appengine apps are designed differently, and those differences are > what allow GAE apps to scale horizontally. > > Robin > > On Sep 19, 7:28 am, hcvst <hcv...@googlemail.com> wrote: > > > > > Hi, > > > I am planning to deploy to GAE and should hopefully see quite a few > > users eventually. > > Does DAL's GAE support scale well? Will I run into the 1000 fetch() > > limit or is that handled > > under the hood for example? > > Should one rather handcraft the Datastore interface with let's say > > 1000 concurrent users or > > will web2py's DAL handle it and handle it efficiently? > > It would be great if someone knowledgeable in web2py's GAE support > > could restate GAE's > > "Best practices for writing scalable applications" > > athttp://code.google.com/appengine/articles/scaling/overview.html > > in terms of web2py's DAL for GAE. It's a lot to ask for, I know, but > > it sure would be great :) > > > Thanks, > > HC --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py-users" group. To post to this group, send email to web2py@googlegroups.com To unsubscribe from this group, send email to web2py+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/web2py?hl=en -~----------~----~----~----~------~----~------~--~---
