This is the first GA release in the 2.9 release line. It includes 30 New Features with 500+ subtasks, 407 Improvements, 790 Bug fixes new fixed issues since 2.8.2. For major features and improvements for Apache Hadoop 2.8.2 please refer: overview of major changes. For details of 790 bug fixes, improvements, and other enhancements since the previous 2.8.2 release, please check: release notes and changelog
Please note: Although this release has been tested on fairly large clusters, production users can wait for a subsequent point release which will contain fixes from further stabilization and downstream adoption.
2017 Dec 17