Merge -c 1499906 from branch-1 to branch-1.2 to fix MAPREDUCE-5368. Reduce memory footprint of JobTracker by using non-default values for hash-tables to store Locality and Avataar for TaskAttempts. Contributed by zhaoyunjiong.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2@1499907 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -49,6 +49,10 @@ Release 1.2.1 - Unreleased
     MAPREDUCE-5375. Use short name for renewing delegation tokens. (Venkat
     Ranganathan via acmurthy)
 
+    MAPREDUCE-5368. Reduce memory footprint of JobTracker by using non-default
+    values for hash-tables to store Locality and Avataar for TaskAttempts.
+    (zhaoyunjiong via acmurthy)
+
 Release 1.2.0 - 2013.05.05
 
   INCOMPATIBLE CHANGES

src/mapred/org/apache/hadoop/mapred/TaskInProgress.java

@@ -131,9 +131,9 @@ class TaskInProgress {
   private String user;
 
   private Map<TaskAttemptID, Locality> taskLocality = 
-      new ConcurrentHashMap<TaskAttemptID, Locality>();
+      new ConcurrentHashMap<TaskAttemptID, Locality>(4, 0.75f, 2);
   private Map<TaskAttemptID, Avataar> taskAvataar = 
-      new ConcurrentHashMap<TaskAttemptID, Avataar>();
+      new ConcurrentHashMap<TaskAttemptID, Avataar>(4, 0.75f, 2);
 
   /**
    * Constructor for MapTask