Appendix B. Road Map
HBase is still being heavily developed. Here is a road map of what is planned in the next releases.
HBase 0.92.0
This upcoming version is being called the Coprocessor Release. The planned availability date is Q3 2011. It adds the following major features:
- Coprocessors
Coprocessors represent a major new feature in HBase. Coprocessors enable users to write code that runs within each region, accessing data directly where it resides. See Coprocessors for details.
- Distributed log splitting
The write-ahead log (WAL) is now split completely distributed on all region servers in parallel. This brings HBase on a par with Bigtable.
- Running tasks in the UI
Previously it was difficult to know what the servers were working on in the background, such as compactions or splits. This is now visualized in the web-based UIs that the master and region servers provide. See Web-based UI for details.
- Performance improvements
Many miscellaneous performance enhancements were added to this release to make it the best performing HBase ever. More than 260 fixes went into 0.92.0 (see https://issues.apache.org/jira/browse/HBASE/fixforversion/12314223 for the full list).
Development for 0.92.0 is still ongoing, even while this book is going into print. Check with the aforementioned link online to see the complete list of features once this version is released.
HBase 0.94.0
Current plans for this version, which is preliminarily being called the Security Release, call for an early 2012 release date. This version is scheduled to include the following new features. See https://issues.apache.org/jira/browse/HBASE/fixforversion/12316419 for more information.
- Security
- Secondary indexes
This coprocessor-backed extension allows you to create and maintain secondary indexes based on columns of tables.
- Search integration
This feature lets you create and maintain a search index, for example, based on Apache Lucene, per region, so that you can perform searches on rows and columns.
- HFile v2
This introduces a new storage format to overcome current limitations with the existing file format.
Other interesting issues are also being worked on and may find their way into this release. One of them is the pluggable block cache feature: it allows you to facilitate a memory manager outside the Java JRE heap. This will reduce the amount of garbage collection churn a large heap causes—which is one of the concerns when running a large-scale HBase cluster with heavy read and write loads.