hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Abdul Qadeer (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-3646) Providing bzip2 as codec
Date Wed, 06 Aug 2008 20:54:48 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-3646?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12620421#action_12620421

Abdul Qadeer commented on HADOOP-3646:

Hi Chris,

As I am writing code to support splitting for bzip2, I want to discuss these
changes with watchers/developers for feedback.  Should I re-open 3646 for it
or make
a new JIRA entry?

Abdul Qadeer

> Providing bzip2 as codec
> ------------------------
>                 Key: HADOOP-3646
>                 URL: https://issues.apache.org/jira/browse/HADOOP-3646
>             Project: Hadoop Core
>          Issue Type: Improvement
>          Components: conf, io
>    Affects Versions: 0.19.0
>            Reporter: Abdul Qadeer
>            Assignee: Abdul Qadeer
>             Fix For: 0.19.0
>         Attachments: HADOOP-3646-version4.patch, HADOOP-3646-version5.patch, HADOOP-3646.patch,
HADOOP-3646.patch, HADOOP-3646version3.patch
>   Original Estimate: 1008h
>  Remaining Estimate: 1008h
> Hadoop recognizes gzip compressed input and automatically decompresses the data before
providing it to the mapper. But Hadoop can not split a gzip stream due to the very nature
of the gzip compression. Consequently one gzip stream (e.g a whole file) can go to only one
mapper.  On the contrary Bzip2 compressed stream can be split across its block delimiters.
> We are interested in extending Hadoop to support splittable bzip2 with a codec.  (https://issues.apache.org/jira/browse/HADOOP-1823
 uses input reader to split the bzip2 files, which must be provided by the user and can handle
FileInputFormat.  If a user wants to use some other input format or wants to do custom record
handling, he must write a new input reader!)
> We have a patch now that provides a basic bzip2 codec equivalent to the current gzip
codec.  We are in the process of extending that to support splitting.

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

View raw message