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https://issues.apache.org/jira/browse/MAPREDUCE-4868?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Allen Wittenauer updated MAPREDUCE-4868:
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Fix Version/s: (was: 2.4.0)
(was: 3.0.0)
> Allow multiple iteration for map
> --------------------------------
>
> Key: MAPREDUCE-4868
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-4868
> Project: Hadoop Map/Reduce
> Issue Type: Improvement
> Components: mrv2
> Affects Versions: 3.0.0, 2.0.3-alpha
> Reporter: Jerry Chen
> Original Estimate: 168h
> Remaining Estimate: 168h
>
> Currently, the Mapper class allows advanced users to override "public void
> run(Context context)" method for more control over the execution of the
> mapper, while Context interface limit the operations over the data which is
> the foundation of "more control".
> One of use cases is that when I am considering a hive optimziation problem, I
> want to go two passes over the input data instead of using a another job or
> task ( which may slower the whole process). Each pass do the same thing but
> with a different parameters.
> This is a new paradigm of Map Reduce usage and can be archived easily by
> extend Context interface a little with the more control over the data such as
> reset the input.
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