Sunday, February 15, 2009

Google App Engine 2, Conclusion of Foray #1 into the cloud.

In the previous post I mentioned several limitations of Google App Engine. In the time that's passed since then (less than a week), Google has announced that several of these restrictions are no more with the release of 1.1.9. Specifically:
  • It is now permissible to use urllib, urllib2 or httplib to make HTTP requests. (previously users were restricted to using urlfetch. Python programmers will be familiar w/ urllib, urllib2, and etc, and welcome this (they won't have to revise modules that use urllib2, as I did with my Blip API wrapper).
  • The dreaded 10-second deadline for a request has been expanded to 30 seconds. While it's still not good form (actually, it's horrible form) to keep a user waiting for 30 seconds, this prevents errors if a website or API you are querying behind the scenes is slow.
  • No more 'high CPU request' warnings. Note that just as George Carlin once observed that buying a 'safe car' doesn't excuse you from the responsibility of learning how to drive, it's also true that this is not Google's way of saying 'to hell with everything, write wasteful code now'
  • The old 1MB limit on requests and responses was raised to 10MB
The take-away point here is that Google listens to user feedback (up to a point: Ruby/PHP/etc users can still suck it, as far as Google App Engine goes), which is encouraging to those investing time and effort in learning the platform.

Unfortunately I ran into some other issues with my application. While my restructuring (using naive, wrote it myself Javascript b/c I wasn't yet familiar with jQuery or the like) led to something much more robust, and the addition of a simple progress bar made waiting for Blip to respond more tolerable, in testing I ran into an issue with the API failing on a call to pull back certain users' 'blips'. Further investigation revealed a 500 error was being returned from the Blip API due to certain characters being present in the string for the blip.

The good people of Blip were, as has always been my experience, quick to respond, and a fix is on the way, but it's not in place yet. As I mentioned in the previous post, the API is still private beta, so this is more a 'shame on me' matter, but as also mentioned in the previous post, this exercise is mostly an excuse to play around with Python and Google App Engine in order to learn more about it and generally 'keep brain from freezing', and as far as that goes, success was had. We'll re-visit it once has a fix in place.

For now, some good resources I've found for learning about the Google App Engine follow.

Web App Wednesday - Michael Bernstein puts out a new web app, plus the code, every week.

Giftag - BestBuy used Google App Engine to put together Giftag, a gift registry add-on for Firefox and Explorer. The blog is a good source of GAE info.

App Engine Fan - This guy has been experimenting with GAE since it was first released, recording the results of his efforts in this blog.

App Engine Samples - code samples from Google itself.

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