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https://issues.apache.org/jira/browse/HDFS-9208?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14947256#comment-14947256
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Chris Nauroth commented on HDFS-9208:
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Hello [~kihwal].
I had filed HADOOP-12390 related to this problem specifically for {{hdfs dfs
-put -p}}. I proposed fixing it at the application layer by supporting
additional flags for preserving specific attributes.
Instead of fixing it in applications, I think I prefer your option #3 here to
allow explicit changes to atime at the NameNode layer. I don't see any harm in
allowing that. A single fix at the NameNode layer would help all applications
that might suffer from this problem.
> Disabling atime may fail clients like distCp
> --------------------------------------------
>
> Key: HDFS-9208
> URL: https://issues.apache.org/jira/browse/HDFS-9208
> Project: Hadoop HDFS
> Issue Type: Bug
> Reporter: Kihwal Lee
> Assignee: Mingliang Liu
>
> When atime is disabled, {{setTimes()}} throws an exception if the passed-in
> atime is not -1. But since atime is 0, distCp fails when it tries to set the
> mtime and atime.
> There are several options:
> 1) make distCp check for 0 atime and call {{setTimes()}} with -1. I am not
> very enthusiastic about it.
> 2) make NN also accept 0 atime in addition to -1, when the atime support is
> disabled.
> 3) support setting mtime & atime regardless of the atime support. The main
> reason why atime is disabled is to avoid edit logging/syncing during
> {{getBlockLocations()}} read calls. Explicit setting can be allowed.
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