Version 2.0.0-beta2

The Dataflow SDK for Java 2.0.0-beta2 is the second 2.x release of the Dataflow SDK for Java, based on a subset of the Apache Beam code base.

• Breaking Changes: The Dataflow SDK 2.x for Java releases have a number of breaking changes from the 1.x series of releases and from earlier 2.x beta releases. Please see below for details.
• Update Incompatibility: The Dataflow SDK 2.x for Java is update-incompatible with Dataflow 1.x. Streaming jobs using a Dataflow 1.x SDK cannot be updated to use a Dataflow 2.x SDK. Additionally, beta releases of 2.x may not be update-compatible with each other or with 2.0.0.

Beta

This is a Beta release of the Dataflow SDK 2.x for Java and includes the following caveats:

• No API Stability: This release does not guarantee a stable API. The next release in the 2.x series may make breaking API changes that require you to modify your code when you upgrade. API stability guarantees will begin with the 2.0.0 release.
• Limited Support Timeline: This release is an early preview of the upcoming 2.0.0 release. It’s intended to let you start the eventual transition to the 2.x series as convenient for you. Beta release are supported by the Dataflow service, but obtaining bugfixes and new features will require you to upgrade to a newer release that may have backwards-incompatible changes. Once 2.0.0 is released, you should plan to upgrade from any 2.0.0-betaX releases within 3 months.
• Documentation and Code Samples: The SDK documentation on the Dataflow site continues to use code samples from the original 1.x SDKs. For the time being, please see the Apache Beam Documentation for background on the APIs in this release.

Updates since 2.0.0-beta1

This release is based on a subset of Apache Beam 0.5.0. The most relevant changes in this release for Cloud Dataflow customers include:

• PubsubIO functionality: Read and Write now provide access to Cloud Pubsub message attributes.
• New scenario: support for stateful pipelines via the new State API.
• New scenario: support for timer via the new Timer API (limited to the DirectRunner in this release).
• Change to PubsubIO construction: PubsubIO.Read and PubsubIO.Write must now be instantiated using PubsubIO.<T>read() and PubsubIO.<T>write() instead of the static factory methods such as PubsubIO.Read.topic(String). Specifying a coder via .withCoder(Coder) for the output type is required for Read. Specifying a coder for the input type or specifying a format function via .withAttributes(SimpleFunction<T, PubsubMessage>) is required for Write.

Additional breaking changes

Please see the official Dataflow SDK 2.x for Java release notes for an updated list of additional breaking changes and updated information on the Dataflow SDK 2.x for Java releases.