Attention, developers! Google’s kicked out their first SDK release of 2010. Version 1.3.1 comes with a handful of new features, as well as notable improvements to the Datastore.
 

Datastore Razzle

  • Datastore Query Cursors - Cursors enable applications to bookmark their progress so that it can be resumed later. Google says this works great in combination with paging URLs, as well as processing in the Task Queue API. 
  • No more 1000 result limit - Whether you're doing a fetch, iterating, or using a Cursor, there's no longer a limits on the number of results.
  • Reduced error rate with Automatic Datastore Retries - Apparently developers are tired of dealing with Datastore's sporadic errors (no surprise there). So now, App Engine automatically retries all datastore calls -- with the exception of transaction commits -- when applications encounter a datastore error. 

Version 1.3.1 Dazzle

For Python: Complete with the AppStats RPC instrumentation library. AppStats lets users profile the performance of calls from their app to the App Engine backend services to identify and isolate issues such as ineffective caching, bottlenecks, and redundant RPC calls in their app. (Google says a Java version is in beta testing now.)

For Java: The new unit-testing framework for your App Engine apps enables users to test application code in a "natural, fully supported manner", and also allows the integration of App Engine apps into other existing testing and automation frameworks. 

Changes in 1.3.1 also include Custom Admin Console pages, Support for wildcard domain mappings, and Java precompilation on by default for all applications. 

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