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From "Owen O'Malley (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-1722) Make streaming to handle non-utf8 byte array
Date Thu, 05 Feb 2009 08:49:59 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-1722?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12670669#action_12670669
] 

Owen O'Malley commented on HADOOP-1722:
---------------------------------------

I'd suggest that we generalize this a little bit more and make the MRInputWriter and MROutputWriter
take the input and output stream. And then instead of:

stream.map.input.typed.bytes=true -> stream.map.input=typed.bytes

So that if someone wants to add another encoder it is trivial to do so.

At some point, we probably should make the AutoInputFormat more complete and promote it into
mapreduce.lib, but clearly that can happen in a different patch.

I'm not that convinced that people will use the typed bytes format outside of python, where
the library is already present, but it does give them an option, which is currently not there.

> Make streaming to handle non-utf8 byte array
> --------------------------------------------
>
>                 Key: HADOOP-1722
>                 URL: https://issues.apache.org/jira/browse/HADOOP-1722
>             Project: Hadoop Core
>          Issue Type: Improvement
>          Components: contrib/streaming
>            Reporter: Runping Qi
>            Assignee: Klaas Bosteels
>         Attachments: HADOOP-1722-v2.patch, HADOOP-1722-v3.patch, HADOOP-1722-v4.patch,
HADOOP-1722-v4.patch, HADOOP-1722.patch
>
>
> Right now, the streaming framework expects the output sof the steam process (mapper or
reducer) are line 
> oriented UTF-8 text. This limit makes it impossible to use those programs whose outputs
may be non-UTF-8
>  (international encoding, or maybe even binary data). Streaming can overcome this limit
by introducing a simple
> encoding protocol. For example, it can allow the mapper/reducer to hexencode its keys/values,

> the framework decodes them in the Java side.
> This way, as long as the mapper/reducer executables follow this encoding protocol, 
> they can output arabitary bytearray and the streaming framework can handle them.

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