[
https://issues.apache.org/jira/browse/HDFS-7056?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14195015#comment-14195015
]
Konstantin Shvachko commented on HDFS-7056:
-------------------------------------------
Guo, wanted to comment on your design doc. Very comprehensive design, thanks.
Feels like you have been working on the implementation.
Our implementation is mostly in line with your design, except section 5.2.9. We
make a copy of the origninal replica in tmpDir, then move it into finalized
dir. That way incomplete replica in case of DN failure will be cleaned up
automatically. We also implemented the optimized case, when the replica can be
truncated in-place if there are no snapshots or upgrades.
The deletion of a file and a snapshot are quite accurate.
> Snapshot support for truncate
> -----------------------------
>
> Key: HDFS-7056
> URL: https://issues.apache.org/jira/browse/HDFS-7056
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: namenode
> Affects Versions: 3.0.0
> Reporter: Konstantin Shvachko
> Assignee: Plamen Jeliazkov
> Attachments: HDFS-7056.patch, HDFSSnapshotWithTruncateDesign.docx
>
>
> Implementation of truncate in HDFS-3107 does not allow truncating files which
> are in a snapshot. It is desirable to be able to truncate and still keep the
> old file state of the file in the snapshot.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
