diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index 52c6669865..aaa222d6dc 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -1065,6 +1065,8 @@ Release 2.7.3 - UNRELEASED
 
   BUG FIXES
 
+    YARN-4347. Resource manager fails with Null pointer exception. (Jian He via wangda)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/RMAppImpl.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/RMAppImpl.java
index 41254d8124..bcfce9a89a 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/RMAppImpl.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/RMAppImpl.java
@@ -1382,7 +1382,7 @@ public static boolean isAppInFinalState(RMApp rmApp) {
         || appState == RMAppState.KILLED;
   }
   
-  private RMAppState getRecoveredFinalState() {
+  public RMAppState getRecoveredFinalState() {
     return this.recoveredFinalState;
   }
 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/RMAppAttemptImpl.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/RMAppAttemptImpl.java
index 48144c35c0..88a89b5854 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/RMAppAttemptImpl.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/RMAppAttemptImpl.java
@@ -83,6 +83,7 @@
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppEventType;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppFailedAttemptEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppImpl;
+import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppState;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.event.RMAppAttemptContainerFinishedEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.event.RMAppAttemptRegistrationEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.event.RMAppAttemptStatusupdateEvent;
@@ -1102,6 +1103,9 @@ private static class AttemptRecoveredTransition
     @Override
     public RMAppAttemptState transition(RMAppAttemptImpl appAttempt,
         RMAppAttemptEvent event) {
+      RMApp rmApp = appAttempt.rmContext.getRMApps().get(
+          appAttempt.getAppAttemptId().getApplicationId());
+
       /*
        * If last attempt recovered final state is null .. it means attempt was
        * started but AM container may or may not have started / finished.
@@ -1109,8 +1113,6 @@ public RMAppAttemptState transition(RMAppAttemptImpl appAttempt,
        */
       if (appAttempt.recoveredFinalState != null) {
         appAttempt.progress = 1.0f;
-        RMApp rmApp =appAttempt.rmContext.getRMApps().get(
-            appAttempt.getAppAttemptId().getApplicationId());
 
         if (appAttempt.submissionContext
             .getKeepContainersAcrossApplicationAttempts()
@@ -1130,7 +1132,24 @@ public RMAppAttemptState transition(RMAppAttemptImpl appAttempt,
               appAttempt, event);
         }
         return appAttempt.recoveredFinalState;
-      } else {
+      } else if (RMAppImpl.isAppInFinalState(rmApp))  {
+        // Somehow attempt final state was not saved but app final state was saved.
+        // Skip adding the attempt into scheduler
+        RMAppState appState = ((RMAppImpl) rmApp).getRecoveredFinalState();
+        LOG.warn(rmApp.getApplicationId() + " final state (" + appState
+            + ") was recorded, but " + appAttempt.applicationAttemptId
+            + " final state (" + appAttempt.recoveredFinalState
+            + ") was not recorded.");
+        switch (appState) {
+        case FINISHED:
+          return RMAppAttemptState.FINISHED;
+        case FAILED:
+          return RMAppAttemptState.FAILED;
+        case KILLED:
+          return RMAppAttemptState.KILLED;
+        }
+        return RMAppAttemptState.FAILED;
+      } else{
         // Add the current attempt to the scheduler.
         if (appAttempt.rmContext.isWorkPreservingRecoveryEnabled()) {
           // Need to register an app attempt before AM can register
@@ -1164,6 +1183,7 @@ public RMAppAttemptState transition(RMAppAttemptImpl appAttempt,
     }
   }
 
+
   private void rememberTargetTransitions(RMAppAttemptEvent event,
       Object transitionToDo, RMAppAttemptState targetFinalState) {
     transitionTodo = transitionToDo;
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/TestWorkPreservingRMRestart.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/TestWorkPreservingRMRestart.java
index 2ef427ed52..05713877c2 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/TestWorkPreservingRMRestart.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/TestWorkPreservingRMRestart.java
@@ -59,6 +59,7 @@
 import org.apache.hadoop.yarn.server.resourcemanager.TestRMRestart.TestSecurityMockRM;
 import org.apache.hadoop.yarn.server.resourcemanager.recovery.MemoryRMStateStore;
 import org.apache.hadoop.yarn.server.resourcemanager.recovery.RMStateStore.RMState;
+import org.apache.hadoop.yarn.server.resourcemanager.recovery.records.ApplicationAttemptStateData;
 import org.apache.hadoop.yarn.server.resourcemanager.recovery.records.ApplicationStateData;
 import org.apache.hadoop.yarn.server.resourcemanager.reservation.ReservationSystemTestUtil;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
@@ -1367,4 +1368,44 @@ public void testContainerCompleteMsgNotLostAfterAMFailedAndRMRestart() throws Ex
     assertEquals(1,loadedAttempt1.getJustFinishedContainers().size());
   }
 
+  // Test that if application state was saved, but attempt state was not saved.
+  // RM should start correctly.
+  @Test (timeout = 20000)
+  public void testAppStateSavedButAttemptStateNotSaved() throws Exception {
+    MemoryRMStateStore memStore = new MemoryRMStateStore() {
+      @Override public synchronized void updateApplicationAttemptStateInternal(
+          ApplicationAttemptId appAttemptId,
+          ApplicationAttemptStateData attemptState) {
+        // do nothing;
+        // simulate the failure that attempt final state is not saved.
+      }
+    };
+    memStore.init(conf);
+    rm1 = new MockRM(conf, memStore);
+    rm1.start();
+
+    MockNM nm1 = new MockNM("127.0.0.1:1234", 15120, rm1.getResourceTrackerService());
+    nm1.registerNode();
+
+    RMApp app1 = rm1.submitApp(200);
+    MockAM am1 = MockRM.launchAndRegisterAM(app1, rm1, nm1);
+    MockRM.finishAMAndVerifyAppState(app1, rm1, nm1, am1);
+
+    ApplicationStateData appSavedState =
+        memStore.getState().getApplicationState().get(app1.getApplicationId());
+
+    // check that app state is  saved.
+    assertEquals(RMAppState.FINISHED, appSavedState.getState());
+    // check that attempt state is not saved.
+    assertNull(appSavedState.getAttempt(am1.getApplicationAttemptId()).getState());
+
+    rm2 = new MockRM(conf, memStore);
+    rm2.start();
+    RMApp recoveredApp1 =
+        rm2.getRMContext().getRMApps().get(app1.getApplicationId());
+
+    assertEquals(RMAppState.FINISHED, recoveredApp1.getState());
+    // check that attempt state is recovered correctly.
+    assertEquals(RMAppAttemptState.FINISHED, recoveredApp1.getCurrentAppAttempt().getState());
+  }
 }