MAPREDUCE-2474. Add docs to the new API Partitioner on how to access the Job Configuration. Contributed by Harsh J Chouraria.
git-svn-id: https://svn.apache.org/repos/asf/hadoop/mapreduce/trunk@1099847 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/CHANGES.txt b/CHANGES.txt
index 18b9e56..5922b2c 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -74,6 +74,9 @@
MAPREDUCE-2420. JobTracker should be able to renew delegation token over
HTTP (Boris Shkolnik via jitendra)
+
+ MAPREDUCE-2474. Add docs to the new API Partitioner on how to access the
+ Job Configuration. (Harsh J Chouraria via todd)
OPTIMIZATIONS
diff --git a/src/java/org/apache/hadoop/mapreduce/Partitioner.java b/src/java/org/apache/hadoop/mapreduce/Partitioner.java
index bff3371..3b846c2 100644
--- a/src/java/org/apache/hadoop/mapreduce/Partitioner.java
+++ b/src/java/org/apache/hadoop/mapreduce/Partitioner.java
@@ -20,6 +20,7 @@
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configurable;
/**
* Partitions the key space.
@@ -31,6 +32,9 @@
* which of the <code>m</code> reduce tasks the intermediate key (and hence the
* record) is sent for reduction.</p>
*
+ * Note: If you require your Partitioner class to obtain the Job's configuration
+ * object, implement the {@link Configurable} interface.
+ *
* @see Reducer
*/
@InterfaceAudience.Public
