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From Ted Yu <yuzhih...@gmail.com>
Subject collision in the naming of '.snapshot' directory between hdfs snapshot and hbase snapshot
Date Tue, 16 Apr 2013 02:13:32 GMT
This afternoon Huned ad I discovered an issue while playing with HBase
Snapshots on top of Hadoop's Snapshot branch (

HDFS (built from HDFS-2802 branch) doesn't allow paths with .snapshot as a
component while HBase tries to create paths with .snapshot as a component.
This leads to issues in HBase, and one of HDFS or HBase needs to give up
the .snapshot reserved keyword. HBase released Snapshots feature in 0.94.6
(quite recently) and it may not be too late to change HBase to use a
different path component in an upcoming new release.

In HBase these path names are not user visible. If there is a deployment of
0.94.6, one could provide a migration tool that renames .snapshot to
.hbase-snapshot or something to be able to move to the Snapshot release of
Hadoop. On the other hand, .snapshot in HDFS is a user visible name and is
a convention that is used by many file systems. It's a matter of
familiarity with such path names that would help users in using HDFS

I am including the hdfs-dev in this email. Would appreciate if we could
work together and come up with a solution.

You can find sample output from hdfs command here:


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