An alpha version of HBase 0.20.0 is available for download at: http://people.apache.org/~stack/hbase-0.20.0-alpha/
We are making this release available to preview what is coming in HBase 0.20.0. In short, 0.20.0 is about performance and high-availability. Also, a new, richer API has been added and the old deprecated. Here is a list of almost 300 issues addressed so far in 0.20.0: http://tinyurl.com/ntvheo This alpha release contains known bugs. See http://tinyurl.com/kvfsft for the current list. In particular, this alpha release is without a migration script to bring your 0.19.x era data forward to work on hbase 0.20.0. A working, well-tested migration script will be in place before we cut the first HBase 0.20.0 release candidate some time in the next week or so. After download, please take the time to review the 0.20.0 'Getting Started' also available here: http://people.apache.org/~stack/hbase-0.20.0-alpha/docs/api/overview-summary.html#overview_description. HBase 0.20.0 has new dependencies, in particular it now depends on ZooKeeper. With ZooKeeper in the mix a few core HBase configurations have been removed and replaced with ZooKeeper configurations instead. Also of note, HBase 0.20.0 will include "Stargate", an improved REST connector for HBase. The old, bundled REST connector will be deprecated. Stargate is implemented using the Jersey framework. It includes protobuf encoding support, has caching proxy awareness, supports batching for scanners and updates, and in general has the goal of enabling Web scale storage systems (a la S3) backed by HBase. Currently its only available up on github, http://github.com/macdiesel/stargate/tree/master. It will be added to a new contrib directory before we cut a release candidate. Please let us know if you have difficulty with the install, if you find the documentation missing or, if you trip over bugs hbasing. Yours, The HBasistas