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https://issues.apache.org/jira/browse/CASSANDRA-1124?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12870877#action_12870877
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Jeremy Hanna commented on CASSANDRA-1124:
-----------------------------------------

Based on the InputSplit.getLocations documentation, it looks like it is just a 
list of hostnames.

http://hadoop.apache.org/common/docs/current/api/org/apache/hadoop/mapreduce/InputSplit.html

But we're trying to see where they try to find nearby nodes if it can't use the 
node the data is local to - i.e. in the same rack or datacenter.

> Improve Cassandra to MapReduce locality sharing
> -----------------------------------------------
>
>                 Key: CASSANDRA-1124
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-1124
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Hadoop
>            Reporter: Jeremy Hanna
>            Priority: Minor
>
> Currently, the hadoop integration only passes the data's local node 
> information (ColumnFamilyRecordReader-RowIterator-getLocation).  Hadoop can 
> take advantage of full locality and it's possible that we have full locality 
> configured in Cassandra.
> So this improvement is for adding the full locality of the data into the 
> String in a way that hadoop can make use of it with its Job/Task Trackers.
> This will allow for jobs to be potentially on the same rack and/or datacenter 
> if possible.

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