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From "Gelesh (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (MAPREDUCE-4974) Optimising the LineRecordReader initialize() method
Date Thu, 07 Feb 2013 05:13:13 GMT

    [ https://issues.apache.org/jira/browse/MAPREDUCE-4974?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13573199#comment-13573199
] 

Gelesh commented on MAPREDUCE-4974:
-----------------------------------

As [~snihalani] has mentioned, a buggy programs that may call next KeyValue..
condition though being a little hypothetical, but still possible.

1) Inorder to avoid that, shall we have the null assignment of key & value in close()
method.?
2) Also shall, we have compressionCodecs also assigned as null  ?

Either me or [~ak.arun@aol.com] would upload a re work on the same.
                
> 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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