Announcing App Engine 1.4.3. Release

Just in time for spring, we have a new App Engine release to bring our Java and Python runtimes even closer to parity. For Python, we’ve launched a test library to match the existing Java testing framework, and for Java we’ve introduced the Deferred and Remote APIs. This release also introduces a new Blobstore writing feature, the experimental release of the Prospective Search API in Python, and a few goodies for Task Queue and Cron users.


  • Prospective Search API: The experimental Prospective Search API allows Python runtime users to detect and take action on datastore entities that match certain criteria when they are written. For the experimental release, users will be allowed 10,000 subscriptions with the Prospective Search API. Pricing will be announced once the feature is fully launched.
  • Testbed Unit Test Framework: The Testbed suite for Python provides an easy interface for using App Engine API stubs in integration tests similar to the previously existing Java Testing Framework. You can create tests for your application that do not rely on calling App Engine production services, which speeds up the time your tests take to complete, and eliminates dependencies for your test on external services. Here at Google, we’re well known for our testing culture, and we hope that this API will allow you to develop more stable code more quickly.


  • Concurrent Requests: Until now, Java applications relied on starting additional instances to dynamically scale up for higher traffic levels. Now with support for concurrent requests, each application instance may serve multiple user requests at the same time. To start, ensure your application’s code is threadsafe, then enable concurrent requests by adding the flag to your appengine-web.xml.
  • Java Remote API and Deferred API support: The Remote API and Deferred API libraries have been supported in Python for awhile, and now they can be used with Java, too! The Remote API allows you to perform operations on your application’s datastore from your local machine. This is particularly useful for work that is not well-suited to App Engine’s request/response model. The Deferred API allows users to more easily write and execute ad hoc tasks. Our docs contain more information and examples on how to use the Remote API and Deferred API in Java App Engine.

New and changed APIs

  • Files API: The new Files API in Python and Java allow you to pragmatically read and write data using Blobstore. This API can be used to generate reports, export data, or do anything that your heart desires that requires large, binary objects.

Serving Changes

  • Task Queue and Cron update: We’ve addressed some of your top requested items for Task Queues and Cron. With this release, you can now configure the specific application version to which a task queue or cron job will send requests. For those wanting to schedule cron jobs with a range syntax like “every 5 minutes from 11:00 to 17:00”, that too is available in the 1.4.3 release. Last, but not least, the Admin Console Task Queues page now displays a more accurate estimate of queue size for queues containing more than 2000 tasks.

Coming soon

Finally, we have a pre-announcement about the 1.4.4 release. In 1.4.0, we introduced a feature that allowed users to download code that they’ve deployed to App Engine. In 1.4.2 we released admin roles allowing for Owners. When 1.4.4 is released, we plan on including a change that allows both the person who uploaded the code to download it, as well as the Owner(s) of the project (as listed in the Admin Console). In preparation for this, be sure to properly assign roles to all developers on your App Engine application in the Admin Console. Alternatively, you will still be able to permanently disable the code download feature for your application.

That’s it for now, for additional information read the full release notes, including all new features and issues fixed for Java and Python. All feedback is welcome and encouraged in our groups.

Leave a Reply