Support for snapshots feature is being worked on in the jira https://issues.apache.org/jira/browse/HDFS-2802. This is an important and a large feature in HDFS. Please see a brief presentation that describes the feature at a highlevel from the Snapshot discussion meetup we had a while back - https://issues.apache.org/jira/secure/attachment/12552861/Snapshots.pdf.
I am exicted to announce that the feature development will soon be completed. Please see the jira for the design and the details of the subtasks. This is a heads up about the merge vote mail that will soon be sent. Details of development and testing: Development has been done in a separate branch - https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-2802. The design is posted at - https://issues.apache.org/jira/secure/attachment/12551474/Snapshots20121030.pdf. The feature development has involved close to 100 subtasks and close to 20K lines of code. A lot of unit tests have been added as a part of the feature. We also have been testing this in a cluster of 5 nodes with a long running test that mimics a real cluster usage with emphasis on use cases related to snapshots. Please see the test plan https://issues.apache.org/jira/secure/attachment/12575442/snapshot-testplan.pdffor the details. Next steps, before calling for merge vote, we need to get the following done: - Add user documentation that describes the feature, and how to use it - Complete some of the pending tasks - Continue testing the feature and fix any bugs that might come up - Update the design document Thanks to everyone who has participated in design and development of this feature. Please review the work and help in testing the feature. Regards, Suresh
