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https://issues.apache.org/jira/browse/HDFS-6268?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Andrew Wang updated HDFS-6268:
------------------------------

    Status: Patch Available  (was: Open)

> Better sorting in NetworkTopology#pseudoSortByDistance when no local node is 
> found
> ----------------------------------------------------------------------------------
>
>                 Key: HDFS-6268
>                 URL: https://issues.apache.org/jira/browse/HDFS-6268
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>    Affects Versions: 2.4.0
>            Reporter: Andrew Wang
>            Assignee: Andrew Wang
>            Priority: Minor
>         Attachments: hdfs-6268-1.patch
>
>
> In NetworkTopology#pseudoSortByDistance, if no local node is found, it will 
> always place the first rack local node in the list in front.
> This became an issue when a dataset was loaded from a single datanode. This 
> datanode ended up being the first replica for all the blocks in the dataset. 
> When running an Impala query, the non-local reads when reading past a block 
> boundary were all hitting this node, meaning massive load skew.



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