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https://issues.apache.org/jira/browse/HADOOP-1869?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12626799#action_12626799
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Raghu Angadi commented on HADOOP-1869:
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+1 for me.. in this jira or a different one, does not matter. sticking to 
posix-like when possible helps since that interface has already gone through 
the arguments..

Actually I wanted to edit my comment make it clear that I am not too opposed to 
setAccessTime()...

> access times of HDFS files
> --------------------------
>
>                 Key: HADOOP-1869
>                 URL: https://issues.apache.org/jira/browse/HADOOP-1869
>             Project: Hadoop Core
>          Issue Type: New Feature
>          Components: dfs
>            Reporter: dhruba borthakur
>            Assignee: dhruba borthakur
>             Fix For: 0.19.0
>
>         Attachments: accessTime1.patch, accessTime4.patch, accessTime5.patch
>
>
> HDFS should support some type of statistics that allows an administrator to 
> determine when a file was last accessed. 
> Since HDFS does not have quotas yet, it is likely that users keep on 
> accumulating files in their home directories without much regard to the 
> amount of space they are occupying. This causes memory-related problems with 
> the namenode.
> Access times are costly to maintain. AFS does not maintain access times. I 
> thind DCE-DFS does maintain access times with a coarse granularity.
> One proposal for HDFS would be to implement something like an "access bit". 
> 1. This access-bit is set when a file is accessed. If the access bit is 
> already set, then this call does not result in a transaction.
> 2. A FileSystem.clearAccessBits() indicates that the access bits of all files 
> need to be cleared.
> An administrator can effectively use the above mechanism (maybe a daily cron 
> job) to determine files that are recently used.

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