This release contains many improvements, new features, bug fixes and optimizations.
Notably, this contains the first working version of HBase.
See the release notes (above) for details.
When upgrading an existing HDFS filesystem to a 0.15.x release from an earlier release, you should first start HDFS with ‘bin/start-dfs.sh -upgrade’. See the Hadoop Upgrade page for details.2007 Oct 29