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From "Surenkumar Nihalani (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (MAPREDUCE-4974) Optimising the LineRecordReader initialize() method
Date Thu, 07 Feb 2013 00:10:13 GMT

    [ https://issues.apache.org/jira/browse/MAPREDUCE-4974?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13573022#comment-13573022
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Surenkumar Nihalani commented on MAPREDUCE-4974:
------------------------------------------------

I am referring to a buggy program that calls nextKeyValue even after we return false. I just
wanted to be sure that the check in the while loop will guard us from calling in.readLine().
in.readLine when passed a null Text type, we will hit NPE. That's the case I am trying to
be safe about.
                
> Optimising the LineRecordReader initialize() method
> ---------------------------------------------------
>
>                 Key: MAPREDUCE-4974
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4974
>             Project: Hadoop Map/Reduce
>          Issue Type: Improvement
>          Components: mrv1, mrv2, performance
>    Affects Versions: 2.0.2-alpha, 0.23.5
>         Environment: Hadoop Linux
>            Reporter: Arun A K
>            Assignee: Gelesh
>              Labels: patch, performance
>             Fix For: 0.20.204.0, 0.24.0
>
>         Attachments: MAPREDUCE-4974.1.patch
>
>   Original Estimate: 1h
>  Remaining Estimate: 1h
>
> I found there is a a scope of optimizing the code, over initialize() if we have compressionCodecs
& codec instantiated only if its a compressed input.
> Mean while Gelesh George Omathil, added if we could avoid the null check of key &
value. This would time save, since for every next key value generation, null check is done.
The intention being to instantiate only once and avoid NPE as well. Hope both could be met
if initialize key & value over  initialize() method. We both have worked on it.

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