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https://issues.apache.org/jira/browse/HADOOP-1708?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12523118
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Sameer Paranjpye commented on HADOOP-1708:
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> Yes we knew this changes the semantics of file creates, but we did not take
> into account that semantics of deletes/renames will change too.
How not? The semantics for delete and rename for files that are being written
are consistent with the semantics of delete and rename for files that are in
the namespace and that have been completed and closed. If a client is reading a
'complete' file and that file gets deleted or renamed then the reader will
fail. Arguably, this is a flaw in the filesystem, but addressing that is a
different discussion.
All this issue does is make files visible in the namespace as they are created
and while they are being written. Delete and rename semantics for these files
are the same as for all other files.
> Would it be more consistent to forbid deletion of files that have active
> leases.
It might be, but the change should apply to all files that are being written or
read. I guess that is what you mean by files with active leases. It might be
better to fix it so that files can be deleted and renamed as they are being
operated on, with POSIX semantics. We should file a different JIRA issue for
this.
> make files visible in the namespace as soon as they are created
> ---------------------------------------------------------------
>
> Key: HADOOP-1708
> URL: https://issues.apache.org/jira/browse/HADOOP-1708
> Project: Hadoop
> Issue Type: Bug
> Components: dfs
> Reporter: dhruba borthakur
> Assignee: dhruba borthakur
> Fix For: 0.15.0
>
> Attachments: 1708-20070820a.patch, atomicCreation2.patch
>
>
> In the current DFS implementation, a file appears in the namespace only when
> the creator closes the file. Also, if the namenode or the client dies before
> closing the file, the file never appears in the namespace.
> This issue will make files appear in the namespace as soon as it is created.
> Also, it will continue to remain in the namespace even if the creator dies
> before closing the file.
> This is related to HADOOP-89. It is different from HADOOP-89 because it does
> not attempt to make data visible as soon as it is written.
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