You are viewing a plain text version of this content. The canonical link for it is here.
Posted to hdfs-dev@hadoop.apache.org by "Andrew Wang (JIRA)" <ji...@apache.org> on 2014/06/04 02:39:02 UTC
[jira] [Resolved] (HDFS-6268) Better sorting in
NetworkTopology#pseudoSortByDistance when no local node is found
[ https://issues.apache.org/jira/browse/HDFS-6268?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Andrew Wang resolved HDFS-6268.
-------------------------------
Resolution: Fixed
Committed new patch to branch-2, thanks for the quick review ATM.
> 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
> Fix For: 3.0.0
>
> Attachments: hdfs-6268-1.patch, hdfs-6268-2.patch, hdfs-6268-3.patch, hdfs-6268-4.patch, hdfs-6268-5.patch, hdfs-6268-branch-2.001.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.
--
This message was sent by Atlassian JIRA
(v6.2#6252)