diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index 98c0b0a0752..bcaf5f29639 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -60,6 +60,9 @@ Release 2.1.1-beta - UNRELEASED
     YARN-906. Fixed a bug in NodeManager where cancelling ContainerLaunch at
     KILLING state causes that the container to hang. (Zhijie Shen via vinodkv)
 
+    YARN-994. HeartBeat thread in AMRMClientAsync does not handle runtime
+    exception correctly (Xuan Gong via bikas)
+
 Release 2.1.0-beta - 2013-08-06
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/async/impl/AMRMClientAsyncImpl.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/async/impl/AMRMClientAsyncImpl.java
index dd03d64e48c..dbea253764b 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/async/impl/AMRMClientAsyncImpl.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/async/impl/AMRMClientAsyncImpl.java
@@ -65,7 +65,7 @@ extends AMRMClientAsync<T> {
   private volatile boolean keepRunning;
   private volatile float progress;
   
-  private volatile Exception savedException;
+  private volatile Throwable savedException;
   
   public AMRMClientAsyncImpl(int intervalMs, CallbackHandler callbackHandler) {
     this(new AMRMClientImpl<T>(), intervalMs, callbackHandler);
@@ -222,18 +222,12 @@ extends AMRMClientAsync<T> {
             
           try {
             response = client.allocate(progress);
-          } catch (YarnException ex) {
-            LOG.error("Yarn exception on heartbeat", ex);
+          } catch (Throwable ex) {
+            LOG.error("Exception on heartbeat", ex);
             savedException = ex;
             // interrupt handler thread in case it waiting on the queue
             handlerThread.interrupt();
             return;
-          } catch (IOException e) {
-            LOG.error("IO exception on heartbeat", e);
-            savedException = e;
-            // interrupt handler thread in case it waiting on the queue
-            handlerThread.interrupt();
-            return;
           }
         }
         if (response != null) {
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/impl/AMRMClientImpl.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/impl/AMRMClientImpl.java
index a7035b9056c..99e896e5f57 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/impl/AMRMClientImpl.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/impl/AMRMClientImpl.java
@@ -277,6 +277,8 @@ public class AMRMClientImpl<T extends ContainerRequest> extends AMRMClient<T> {
   public void unregisterApplicationMaster(FinalApplicationStatus appStatus,
       String appMessage, String appTrackingUrl) throws YarnException,
       IOException {
+    Preconditions.checkArgument(appStatus != null,
+        "AppStatus should not be null.");
     FinishApplicationMasterRequest request =
         FinishApplicationMasterRequest.newInstance(appStatus, appMessage,
           appTrackingUrl);
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/api/async/impl/TestAMRMClientAsync.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/api/async/impl/TestAMRMClientAsync.java
index 0d96185ec4b..710f3487481 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/api/async/impl/TestAMRMClientAsync.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/api/async/impl/TestAMRMClientAsync.java
@@ -159,14 +159,26 @@ public class TestAMRMClientAsync {
 
   @Test(timeout=10000)
   public void testAMRMClientAsyncException() throws Exception {
+    String exStr = "TestException";
+    YarnException mockException = mock(YarnException.class);
+    when(mockException.getMessage()).thenReturn(exStr);
+    runHeartBeatThrowOutException(mockException);
+  }
+
+  @Test(timeout=10000)
+  public void testAMRMClientAsyncRunTimeException() throws Exception {
+    String exStr = "TestRunTimeException";
+    RuntimeException mockRunTimeException = mock(RuntimeException.class);
+    when(mockRunTimeException.getMessage()).thenReturn(exStr);
+    runHeartBeatThrowOutException(mockRunTimeException);
+  }
+
+  private void runHeartBeatThrowOutException(Exception ex) throws Exception{
     Configuration conf = new Configuration();
     TestCallbackHandler callbackHandler = new TestCallbackHandler();
     @SuppressWarnings("unchecked")
     AMRMClient<ContainerRequest> client = mock(AMRMClientImpl.class);
-    String exStr = "TestException";
-    YarnException mockException = mock(YarnException.class);
-    when(mockException.getMessage()).thenReturn(exStr);
-    when(client.allocate(anyFloat())).thenThrow(mockException);
+    when(client.allocate(anyFloat())).thenThrow(ex);
 
     AMRMClientAsync<ContainerRequest> asyncClient = 
         AMRMClientAsync.createAMRMClientAsync(client, 20, callbackHandler);
@@ -183,14 +195,14 @@ public class TestAMRMClientAsync {
         }
       }
     }
-    
-    Assert.assertTrue(callbackHandler.savedException.getMessage().contains(exStr));
+    Assert.assertTrue(callbackHandler.savedException.getMessage().contains(
+        ex.getMessage()));
     
     asyncClient.stop();
     // stopping should have joined all threads and completed all callbacks
     Assert.assertTrue(callbackHandler.callbackCount == 0);
   }
-  
+
   @Test//(timeout=10000)
   public void testAMRMClientAsyncReboot() throws Exception {
     Configuration conf = new Configuration();