[jira] Commented: (HADOOP-4640) Add ability to split text files compressed with lzo

["Johan Oskarsson (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HADOOP-4640?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12646899#action_12646899 ] 

Johan Oskarsson commented on HADOOP-4640:
-----------------------------------------

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.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.