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Yongjun Zhang commented on HDFS-12544: -------------------------------------- Hi [~manojg], One thought, about snapshotDiff to scoped dir, if we have a move operation "mv x y", where x is in the scoped dir, and y is not in scoped dir, but both are in snapshot root hierarchy. There are two issues: # If we do snapshotDiff on snapshot root, we will get a "rename" operation, this helps distcp to do a "sync" without copying renamed file. With the change of this jira, we will lose the optimization. If the different sub-dirs are very independent, then we are fine. We can document this though. # With this change, it's expected that we get a "delete" entry when doing snapshotDiff at the source dir and "new" entry when doing snapshotDiff at the target dir. Would you please confirm if this is the case? # If the result of 2 is not as expected, we need to have new patch rev to fix it. Thanks. > SnapshotDiff - support diff generation on any snapshot root descendant > directory > -------------------------------------------------------------------------------- > > Key: HDFS-12544 > URL: https://issues.apache.org/jira/browse/HDFS-12544 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs > Affects Versions: 3.0.0-beta1 > Reporter: Manoj Govindassamy > Assignee: Manoj Govindassamy > Attachments: HDFS-12544.01.patch, HDFS-12544.02.patch, > HDFS-12544.03.patch > > > {noformat} > # hdfs snapshotDiff <snapshot_root_path> <from_snapshot_name> > <to_snapshot_name> > {noformat} > Using snapshot diff command, we can generate a diff report between any two > given snapshots under a snapshot root directory. The command today only > accepts the path that is a snapshot root. There are many deployments where > the snapshot root is configured at the higher level directory but the diff > report needed is only for a specific directory under the snapshot root. In > these cases, the diff report can be filtered for changes pertaining to the > directory we are interested in. But when the snapshot root directory is very > huge, the snapshot diff report generation can take minutes even if we are > interested to know the changes only in a small directory. So, it would be > highly performant if the diff report calculation can be limited to only the > interesting sub-directory of the snapshot root instead of the whole snapshot > root. -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org