This task aims to backport
HDFS-12882 and some connecting commits to branch-3.0 without introducing API incompatibilities.
In order to be able to cleanly backport, first
HDFS-7878, then HDFS-12877 should be backported to that branch as well (both can be executed cleanly, and with build success).
Also, this patch would also introduce API backward incompatibilities in hadoop-hdfs-client, and we should modify it to a compat change (similar as in
HDFS-13830 fought with this problem).
- is blocked by
HDFS-7878 API - expose a unique file identifier