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https://issues.apache.org/jira/browse/HDFS-3702?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Lei (Eddy) Xu updated HDFS-3702:
--------------------------------
             Assignee: Lei (Eddy) Xu
     Target Version/s: 2.7.0
    Affects Version/s:     (was: 2.0.0-alpha)
                           (was: 1.0.3)
                       2.5.1
               Status: Patch Available  (was: Open)

> Add an option for NOT writing the blocks locally if there is a datanode on 
> the same box as the client
> -----------------------------------------------------------------------------------------------------
>
>                 Key: HDFS-3702
>                 URL: https://issues.apache.org/jira/browse/HDFS-3702
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: hdfs-client
>    Affects Versions: 2.5.1
>            Reporter: Nicolas Liochon
>            Assignee: Lei (Eddy) Xu
>            Priority: Minor
>         Attachments: HDFS-3702.000.patch
>
>
> This is useful for Write-Ahead-Logs: these files are writen for recovery 
> only, and are not read when there are no failures.
> Taking HBase as an example, these files will be read only if the process that 
> wrote them (the 'HBase regionserver') dies. This will likely come from a 
> hardware failure, hence the corresponding datanode will be dead as well. So 
> we're writing 3 replicas, but in reality only 2 of them are really useful.



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