You are viewing a plain text version of this content. The canonical link for it is here.
Posted to common-dev@hadoop.apache.org by "Runping Qi (JIRA)" <ji...@apache.org> on 2006/05/17 01:09:07 UTC
[jira] Updated: (HADOOP-115) Hadoop should allow the user to use
SequentialFileOutputformat as the output format and to choose key/value
classes that are different from those for map output.
[ http://issues.apache.org/jira/browse/HADOOP-115?page=all ]
Runping Qi updated HADOOP-115:
------------------------------
Attachment: patch_115.txt.2006_05_16
My patch is attached.
Change highlights:
JobConf.java:
Added set/getMapOutputKey/ValueClass methods
Modified getOutputKeyComparatorClass
MapTask.java:
call getMapOutputKey/ValueClass instead of getOutputKey/ValueClass
MapReduce.java:
call getMapOutputKey/ValueClass instead of getOutputKey/ValueClass
MapOutputFile.java:
call getMapOutputKey/ValueClass instead of getOutputKey/ValueClass
I've run a job with a combiner, with UTF8 as the map output value class, and CrawledDoc as the output value class.
The job completed successfully.
> Hadoop should allow the user to use SequentialFileOutputformat as the output format and to choose key/value classes that are different from those for map output.
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: HADOOP-115
> URL: http://issues.apache.org/jira/browse/HADOOP-115
> Project: Hadoop
> Type: Improvement
> Components: mapred
> Reporter: Runping Qi
> Assignee: Runping Qi
> Attachments: hadoop-115_ReduceTask.patch, hadoop-115_tk.patch, patch_115.txt.2006_05_16
>
> When map tasks write intermediate data out, they always use SequencialFile RecordWriter with key/value classes from the job object.
> When the reducers write the final results out, its output format is obtained from the job object. By default, it is TextOutputFormat, and no conflicts.
> However, if one wants to use SequencialFileFormat for the final results, then the key/value classes are also obtained from the job object, the same as the map tasks' output. Now we have a problem. It is impossible for the map outputs and reducer outputs use different key/value classes, if one wants the reducers generate outputs in SequentialFileFormat.
> A simple fix would be to add another two attributes to JobConf class: mapOutputLeyClass and mapOutputValueClass. That allows the user to have different key/value classes for the intermediate and final outputs.
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
http://www.atlassian.com/software/jira