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From "Vinay (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (MAPREDUCE-5656) bzip2 codec can drop records when reading data in splits
Date Thu, 28 Nov 2013 01:55:35 GMT

    [ https://issues.apache.org/jira/browse/MAPREDUCE-5656?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13834447#comment-13834447
] 

Vinay commented on MAPREDUCE-5656:
----------------------------------

I have one doubt here,

Say, last record ended between delimiters and {{needAdditionalRecord}} is true and one more
record is read to buffer.
What if this record also ended between delimiters..? 
Now also {{needAdditionalRecord}} will be true and this will try to read one more record right..?
This will be duplicated in next split.

may be we need to set {{needAdditionalRecord}} only if its not already been set to true. Right?

> bzip2 codec can drop records when reading data in splits
> --------------------------------------------------------
>
>                 Key: MAPREDUCE-5656
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-5656
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>    Affects Versions: 2.0.4-alpha, 0.23.8
>            Reporter: Jason Lowe
>            Assignee: Jason Lowe
>            Priority: Critical
>         Attachments: HADOOP-9622-2.patch, HADOOP-9622-testcase.patch, HADOOP-9622.patch,
MAPREDUCE-5656.patch, blockEndingInCR.txt.bz2, blockEndingInCRThenLF.txt.bz2
>
>
> Bzip2Codec.BZip2CompressionInputStream can cause records to be dropped when reading them
in splits based on where record delimiters occur relative to compression block boundaries.
> Thanks to [~knoguchi] for discovering this problem while working on PIG-3251.



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