[
https://issues.apache.org/jira/browse/HDFS-3107?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14155367#comment-14155367
]
Konstantin Shvachko commented on HDFS-3107:
-------------------------------------------
[~cmccabe] feels like some clarification is needed from you here, so that we
could avoid misunderstanding like in the other jira.
# I assume that your [veto of Sept 17 conditional on the design
document|https://issues.apache.org/jira/browse/HDFS-3107?focusedCommentId=14137882&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14137882]
had been addressed. Now with subsequent corrections in line with your
suggestions.
# [Earlier this week you
stated|https://issues.apache.org/jira/browse/HDFS-3107?focusedCommentId=14152094&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14152094]
??we should hold off on committing to trunk until we figure out the snapshot
story.??
Given the design in place, the subtask HDFS-7056 opened, and the general
acceptance of the approach by other contributors, the snapshot story seem to be
clear.
So if your statement is a veto could you please clarify the reason(s)? If not
please say so, so that people could proceed with the subtasks? I hope you can
reply by tomorrow.
> HDFS truncate
> -------------
>
> Key: HDFS-3107
> URL: https://issues.apache.org/jira/browse/HDFS-3107
> Project: Hadoop HDFS
> Issue Type: New Feature
> Components: datanode, namenode
> Reporter: Lei Chang
> Assignee: Plamen Jeliazkov
> Attachments: HDFS-3107.patch, HDFS-3107.patch, HDFS-3107.patch,
> HDFS-3107.patch, HDFS-3107.patch, HDFS_truncate.pdf, HDFS_truncate.pdf,
> HDFS_truncate_semantics_Mar15.pdf, HDFS_truncate_semantics_Mar21.pdf,
> editsStored
>
> Original Estimate: 1,344h
> Remaining Estimate: 1,344h
>
> Systems with transaction support often need to undo changes made to the
> underlying storage when a transaction is aborted. Currently HDFS does not
> support truncate (a standard Posix operation) which is a reverse operation of
> append, which makes upper layer applications use ugly workarounds (such as
> keeping track of the discarded byte range per file in a separate metadata
> store, and periodically running a vacuum process to rewrite compacted files)
> to overcome this limitation of HDFS.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
