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https://issues.apache.org/jira/browse/HADOOP-4640?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12646899#action_12646899
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Johan Oskarsson commented on HADOOP-4640:
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I've got a working input format that can split lzo files. It requires an index
of the file to be created before the lzo file can be split.
In a fairly non scientific experiment I got 30% performance increase using this
compared to reading the uncompressed files on our 20 node cluster.
I need to clean up and test the code a bit before I'll submit it.
> Add ability to split text files compressed with lzo
> ---------------------------------------------------
>
> Key: HADOOP-4640
> URL: https://issues.apache.org/jira/browse/HADOOP-4640
> Project: Hadoop Core
> Issue Type: Improvement
> Components: io, mapred
> Reporter: Johan Oskarsson
> Assignee: Johan Oskarsson
> Priority: Trivial
>
> Right now any file compressed with lzop will be processed by one mapper. This
> is a shame since the lzo algorithm would be very suitable for large log files
> and similar common hadoop data sets. The compression rate is not the best out
> there but the decompression speed is amazing. Since lzo writes compressed
> data in blocks it would be possible to make an input format that can split
> the files.
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