App Engine
12 Aug 2008This is a quick screencast to show you the data export solution I've created for Google App Engine that lets you backup your application's datastore and restore it either locally on your development machine or on the same Google App Engine application on the deployment environment or on a different Google App Engine application (which you can use as a staging environment).
A new version of the Google App Engine Helper for Django has been released.
Release notes (Wed 6 August 2008) follow:
Google App Engine, we need to have a talk about your datastore keys.
Your keys can have names but they cannot start with a number. Keys can also have IDs, which are numeric. We can read those, but can't set them.
When I put an entity into the datastore for the first time, you assign it a numeric ID. I'd love to be able to create an entity on a different instance with the same ID you've assigned it but I can't. I'd love to be able to create an entity with the same key that you've assigned it (again, on a separate instance -- say the local SDK or a different app), but I can't set keys directly.
One of the things that I love about Python is that it has all the documentation you ever need (all right, almost) in the code itself. Many moons ago, the very first framework I wrote in ActionScript (Flash 5) used the same technique by placing documentation on the activation objects of functions (and it would be cool to see that practice make a comeback in AS3.)
In Python, to find out what properties an object has, you just ask for a listing. The following, for example, shows you all properties and methods on the os module.
Amazon S3 has been down for several hours now and as Jonathan Boutelle (who, by the way is speaking at the Singularity Web Conference) writes, when S3 goes down, the Internet goes down. Along with images on Twitter, SlideShare, SmugMug, and a host of other sites, images on Pistach.io ads are also down. We've also had intermittent issues with Amazon's SimpleDB. I feel that these issues only serve to highlight the age-old danger of having all your eggs in one basket. Especially a proprietary basket. This is why I applaud Google in releasing the Google App Engine SDK as open source.
The launch of services like Amazon's EC2, S3, SimpleDB and Google's Google App Engine herald the birth of the Commodity Web, wherein web infrastructure is infinitely available and metered just like electricity, water, and gas. For the most part, we don't think about the limits or availability of commodities (as the impending ecological nightmare we've woven for ourselves would attest to, if nothing else.) But when we do try those limits, or when the systems of delivery break down (as in blackouts, for example), the extent of our reliance on these utilities becomes painfully clear.