diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index f0ee2df1c90..479cfb7fbf7 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -54,6 +54,9 @@ Release 2.0.5-beta - UNRELEASED
     YARN-309. Changed NodeManager to obtain heart-beat interval from the
     ResourceManager. (Xuan Gong via vinodkv)
 
+    YARN-447. Move ApplicationComparator in CapacityScheduler to use comparator
+    in ApplicationId. (Nemon Lou via vinodkv)
+
   OPTIMIZATIONS
 
   BUG FIXES
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/CapacityScheduler.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/CapacityScheduler.java
index 1b3858cc864..3a4b5248d23 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/CapacityScheduler.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/CapacityScheduler.java
@@ -108,7 +108,7 @@ implements ResourceScheduler, CapacitySchedulerContext, Configurable {
     new Comparator<FiCaSchedulerApp>() {
     @Override
     public int compare(FiCaSchedulerApp a1, FiCaSchedulerApp a2) {
-      return a1.getApplicationId().getId() - a2.getApplicationId().getId();
+      return a1.getApplicationId().compareTo(a2.getApplicationId());
     }
   };
 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestCapacityScheduler.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestCapacityScheduler.java
index 48717ed8d02..66f9059de99 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestCapacityScheduler.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestCapacityScheduler.java
@@ -19,8 +19,10 @@
 package org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import java.io.IOException;
+import java.util.Comparator;
 import java.util.List;
 
 import junit.framework.Assert;
@@ -43,13 +45,19 @@ import org.apache.hadoop.yarn.server.resourcemanager.Task;
 import org.apache.hadoop.yarn.server.resourcemanager.resource.Resources;
 import org.apache.hadoop.yarn.server.resourcemanager.rmnode.RMNode;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.common.fica.FiCaSchedulerApp;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.event.NodeAddedSchedulerEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.event.NodeRemovedSchedulerEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.security.ClientToAMTokenSecretManagerInRM;
 import org.apache.hadoop.yarn.server.resourcemanager.security.RMContainerTokenSecretManager;
+import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.factory.providers.RecordFactoryProvider;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+import org.mockito.Mockito;
+import static org.mockito.Mockito.*;
+
 
 public class TestCapacityScheduler {
   private static final Log LOG = LogFactory.getLog(TestCapacityScheduler.class);
@@ -452,5 +460,33 @@ public class TestCapacityScheduler {
     }
     return result;
   }
+  
+    
+    @Test (timeout = 5000)
+    public void testApplicationComparator()
+    {
+      CapacityScheduler cs = new CapacityScheduler();
+      Comparator<FiCaSchedulerApp> appComparator= cs.getApplicationComparator();
+      ApplicationId id1 = RecordFactoryProvider.getRecordFactory(null).newRecordInstance(ApplicationId.class);
+      id1.setClusterTimestamp(1);
+      id1.setId(1);
+      ApplicationId id2 = RecordFactoryProvider.getRecordFactory(null).newRecordInstance(ApplicationId.class);
+      id2.setClusterTimestamp(1);
+      id2.setId(2);
+      ApplicationId id3 = RecordFactoryProvider.getRecordFactory(null).newRecordInstance(ApplicationId.class);
+      id3.setClusterTimestamp(2);
+      id3.setId(1);
+      //same clusterId
+      FiCaSchedulerApp app1 = Mockito.mock(FiCaSchedulerApp.class);
+      when(app1.getApplicationId()).thenReturn(id1);
+      FiCaSchedulerApp app2 = Mockito.mock(FiCaSchedulerApp.class);
+      when(app2.getApplicationId()).thenReturn(id2);
+      FiCaSchedulerApp app3 = Mockito.mock(FiCaSchedulerApp.class);
+      when(app3.getApplicationId()).thenReturn(id3);
+      assertTrue(appComparator.compare(app1, app2) < 0);
+      //different clusterId
+      assertTrue(appComparator.compare(app1, app3) < 0);
+      assertTrue(appComparator.compare(app2, app3) < 0);
+    }
 
 }
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestUtils.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestUtils.java
index 7ca43421d99..113e16ed7f4 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestUtils.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestUtils.java
@@ -49,6 +49,7 @@ import org.apache.hadoop.yarn.server.resourcemanager.scheduler.common.fica.FiCaS
 import org.apache.hadoop.yarn.server.resourcemanager.security.ApplicationTokenSecretManager;
 import org.apache.hadoop.yarn.server.resourcemanager.security.ClientToAMTokenSecretManagerInRM;
 import org.apache.hadoop.yarn.server.resourcemanager.security.RMContainerTokenSecretManager;
+import org.apache.hadoop.yarn.util.BuilderUtils;
 
 public class TestUtils {
   private static final Log LOG = LogFactory.getLog(TestUtils.class);
@@ -136,9 +137,7 @@ public class TestUtils {
   
   public static ApplicationAttemptId 
   getMockApplicationAttemptId(int appId, int attemptId) {
-    ApplicationId applicationId = mock(ApplicationId.class);
-    when(applicationId.getClusterTimestamp()).thenReturn(0L);
-    when(applicationId.getId()).thenReturn(appId);
+    ApplicationId applicationId = BuilderUtils.newApplicationId(0l, appId);
     ApplicationAttemptId applicationAttemptId = mock(ApplicationAttemptId.class);  
     when(applicationAttemptId.getApplicationId()).thenReturn(applicationId);
     when(applicationAttemptId.getAttemptId()).thenReturn(attemptId);