Cassandra 2.2

Cassandra 2.2 is now generally available, including the following highlights:

• Microsoft Windows is now ready for production deployments.
• JSON data can now be inserted, updated, and retrieved directly to and from Cassandra.
• User-defined functions can be created from Java, Javascript, and other languages supporting the Java Scripting API.  By allowing more computation to be done in Cassandra, UDF can bring big performance gains since you no longer have to pull all the data into your application first. See the two part coverage here and here.
• A number of performance enhancements have been added, most notably including commitlog compression. Message coalescing was already available as an option starting in Cassandra 2.1.5, but is enabled by default in 2.2.
• Streaming data between nodes with leveled compaction enabled is much more efficient. This is particularly useful when rebuilding a failed node, or bringing a new datacenter online.
• Role-based access control simplifies administration for teams and departments with shared security requirements.