[
https://issues.apache.org/jira/browse/HADOOP-1230?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12651303#action_12651303
]
Sharad Agarwal commented on HADOOP-1230:
----------------------------------------
Is there a need to explicitly pass Context object in map and cleanup methods?
These are expected to be called after setup. Would it be better to set Context
in a protected member variable in setup? map and cleanup are expected to use
the same reference of Context, right?
I think this will simplify the code as we would require to pass Context to only
2 methods out of 4. So may not even require to create a shorthand Mapper#Context
Going forward also if we add more methods, it will keep the method signatures
simple.
> 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.
