Last week we announced our 1.3.6 release with lots of new, exciting features to try out. After it was released, developers dug into all the new functional and discovered a pair of issues that required a quick fix. Today we are releasing version 1.3.7 of the SDK in both Java and Python to fix two issues that shipped with last week’s release 1.3.6.
The first issue was with the Python SDK, which was missing the functionality to assign a namespace based on the Google Apps domain. With this release the function google_apps_namespace() should exist and function as documented.
The second issue we fixed was with the Java SDK. The getServingUrl() function for the new dynamic image resizing service was throwing a SecurityException in the SDK. This issue has now been fixed and this function should work as expected.
Thank you to all the people who reported these issues. Please visit the download page to get the new version of the SDK.
Today marks the 1.3.6 release of App Engine for Java and Python. In this release we have made available several exciting new features, relaxed quota and datastore limitations, and added various issue fixes.
We are pleased to announce support for multi-tenancy for applications via the Namespaces API. With multi-tenancy, multiple client organizations (or “tenants”) can all run the same application, segregating data using a unique namespace for each client. This allows you to easily serve the same app to multiple different customers, with each customer seeing their own unique copy of the app. No changes in your code are necessary to use this API-- just a little extra configuration. Further, the API is also designed to be very customizable, with hooks into your code that you can control, so you can set up multi-tenancy in any way you choose.
Check out our application examples for Java and Python to demonstrate how to use the Namespaces API in your application. The API works will all of the relevant App Engine APIs (Datastore, Memcache, and Task Queues). Check out our docs for Java and Python to learn more.
This release also includes a new, high-performance image serving system for your applications, based on the same infrastructure we use to serve images for Picasa. This feature allows you to generate a stable, dedicated URL for serving web-suitable image thumbnails. You simply store a single copy of your original image in Blobstore, and then request a high-performance per-image URL. This special URL can serve that image resized and/or cropped automatically, and serving from this URL does not incur any CPU or dynamic serving load on your application (though bandwidth is still charged as usual). It’s easy to use, just call the Python function get_serving_url, or the Java function getServingUrl and supply a Blob key (with optional serving size and/or crop arguments), and you can now serve dozens or hundreds of thumbnails on a single page with ease. To enable high performance image serving in your deployed application, you'll need to enable billing.
Since launch, many developers have asked to be able to serve custom error pages instead of those automatically served by App Engine. We are happy to announce today we are supporting static HTML error pages that can be served for you automatically for over quota, DoS, timeout and other generic error cases, that you previously could not control. You can configure custom error handlers in your app.yaml or appengine-web.xml file. Check out the Java or Python docs for more information.
We have also continued the trend of lifting some system limitations that have been in place since launch. The Datastore no longer enforces a 1000 entity limit on for count and offset. Queries using these will now safely execute until they return or your application reaches the request timeout limit. Also, based on your feedback, we have raised nearly all of the burst quotas for free apps to the same level as the burst quotas for billed apps. Check out the docs for more information on quota limits.
In addition to all of the new features, we’ve included several bug fixes which you can read all about in the release notes for Java and Python.
-- Posted by the App Engine team
We recently announced the Mapper API, a first step in a broader effort to provide full MapReduce capabilities on App Engine. While we still have some work ahead of us, there’s already a lot that can be done with today’s Mapper API. One area of particular interest is report generation.
Most applications create and maintain large numbers of detail records: entities in data models, transaction history or event logs. In order to glean useful information out of these vast data sets, your application has to iterate over your entities, summarize and breakdown the results. That’s where the Mapper API comes in.
The Mapper API uses the Task Queue to enable your application to rapidly iterate over its data sets, whether small or very, very large. The API takes care of the tedious bookkeeping involved in efficiently scheduling and keeping track of all those tasks. The Task Queue, in turn, automatically ‘pushes’ the work to your app.
Christopher O’Donnell (@markitecht), a technology product designer and developer from Cambridge, Massachusetts, was kind enough to share with us some of the motivations and implementation details behind his own project. In a new guest article, Modern Funnel Analytics Using Mapper, Christopher makes extensive use of the Mapper API to illustrate the process of generating rollup reports. With his approach, he's able to provide both summarized results and drill down capabilities.
If you like Christopher’s article, you should also checkout out the many other interesting articles on the Google App Engine home page. And, if you have an interesting App Engine article or story you'd like to share, let us know. We'd love to hear about it.
Posted by Fred Sauer, App Engine Team
"As you know, we were massively against the clock with the launch of the cycle hire scheme, and we needed something we could get going with fast that would effortlessly scale to perhaps tens of thousands of mobile users. App Engine seemed the perfect choice from what we had read of it before the meeting, and after your presentation it was obviously the way to go. Your recommendation to use Python was scary given neither of us knew a thing about it, but then again we only knew Java from Android not from web development so we didn't have the domain knowledge of building Java web services. So we went with Python, and it worked out really well. I'm astounded how we actually delivered this product in a very short space of time when we both have full schedules working on projects for our clients and other demanding outside interests. Particularly satisfying was having a solution that was agile and flexible enough to enable us to display live cycle availability data within hours of it becoming unexpectedly available at the launch, so we were live in the field with real-time data that very same launch morning, a feature our competitors are still struggling to replicate."
"The single coolest thing about this project is that it was possible to go from a state of knowing nothing whatsoever about App Engine or Python (other than the mile-high view) to having a working and useful application inside of eight hours. We're long-time geeks but we're not geniuses. For us to pick up a new language, a new SDK, a new environment, a new way of doing things, and produce anything of value at all in such a short time speaks volumes about the value, potential, and quality of App Engine and Python.After installing the App Engine SDK, yes, the very first thing I did was your online tutorial. I did "Hello World" to find my feet then continued into webapp, since a clean URL handler with easy ways to get at HTTP variables seemed essential. Then I immediately jumped into learning about data storage. And wow, what an enlightenment that turned out to be! Goodbye SQL, don't think I'm going to miss ya.... :-)Since the app's purpose is to manage just ~400 simple objects representing Cycle Hire Stations, each of which contains only Plain Old Data types — no object references or anything possibly messy — I felt I knew enough to implement it now, and so I dived in. And it was so easy! I started with a handler to rebuild the datastore from scratch. Then I wrote a "get" type of handler to retrieve information about groups of hire stations (returning the data in JSON). Finally I wrote an "update" handler so that updated information about cycle hire stations could be posted, and that was it. Job done.One thing that initially confounded me was an HTTP 500 error caused by our "reset" handler exceeding the 30-second request limit. For a while I was ready to despair; HTTP 500s to anyone with much ASP experience usually means a hideous low-level bug somewhere! However, once we discovered the problem, this was easy to fix by splitting the work into multiple requests (/reset1, /reset2, etc.) It's an admin function that only we'd ever be using, so no harm done and no need to work out anything more clever.I know we've barely scratched the surface of what can be done with App Engine. We've yet to use Memcache, background tasks, batched updates, or anything beyond simple cloud-based data storage. But that simple thing alone seemed then, and still seems, not far short of miraculous. To not have to worry about databases, servers, uptime, upgrades and above all scaling... to not have to think about any of that at all is such an immense freedom. I'm completely hooked on it and am unlikely to go back to my traditional server tools of MySQL and PHP.
"We formed Little Fluffy Toys Ltd as a vehicle for Android development where we do consultancy work as well as our own stuff like the Cycle Hire Widget and Social Wallpaper. Whilst all custom development enquiries are very welcome, we're also interested in hearing from people or organisations that would like us to customise Cycle Hire Widget for their particular domain, whether it's cycles with availability in another city, coffee shops with opening hours in a geographic region, or dieting group meetings at pertinent times nearby. You name it, there are a gazillion applications for it!"