[
https://issues.apache.org/jira/browse/HADOOP-1230?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12617891#action_12617891
]
Owen O'Malley commented on HADOOP-1230:
---------------------------------------
{quote}
* All the Job setters can only be meaningfully called before the job is
submitted, right? Perhaps we ought to explicitly check that, and throw an
exception when the job's already submitted?
{quote}
That makes sense.
{quote}
* Shouldn't Partitioner be an abstract class instead of an interface, that
uses Math.abs(key.hashCode()) by default?
* Should OutputFormat also be an abstract class instead of an interface,
like InputFormat?
{quote}
I guess so. I can't see any reasonable excuse for implementing multiple of
these interfaces in the same class.
> Replace parameters with context objects in Mapper, Reducer, Partitioner,
> InputFormat, and OutputFormat classes
> --------------------------------------------------------------------------------------------------------------
>
> Key: HADOOP-1230
> URL: https://issues.apache.org/jira/browse/HADOOP-1230
> Project: Hadoop Core
> Issue Type: Improvement
> Components: mapred
> Reporter: Owen O'Malley
> Assignee: Owen O'Malley
> Attachments: context-objs-2.patch, context-objs-3.patch,
> context-objs.patch
>
>
> This is a big change, but it will future-proof our API's. To maintain
> backwards compatibility, I'd suggest that we move over to a new package name
> (org.apache.hadoop.mapreduce) and deprecate the old interfaces and package.
> Basically, it will replace:
> package org.apache.hadoop.mapred;
> public interface Mapper extends JobConfigurable, Closeable {
> void map(WritableComparable key, Writable value, OutputCollector output,
> Reporter reporter) throws IOException;
> }
> with:
> package org.apache.hadoop.mapreduce;
> public interface Mapper extends Closable {
> void map(MapContext context) throws IOException;
> }
> where MapContext has the methods like getKey(), getValue(), collect(Key,
> Value), progress(), etc.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
