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https://issues.apache.org/jira/browse/HDFS-9208?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14948658#comment-14948658
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Kihwal Lee commented on HDFS-9208:
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Really #3 is the only option. I was wrong about atime being 0. When {{INode}}
is created, the atime and mtime are set to identical value. option 1) and 2)
are not possible.
> 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 not -1, 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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