YARN-4347. Resource manager fails with Null pointer exception. (Jian He via wangda)

hadoop-yarn-project/CHANGES.txt

@@ -18,6 +18,8 @@ Release 2.7.3 - UNRELEASED
     YARN-3840. Resource Manager web ui issue when sorting application by id (with
     application having id > 9999) (Mohammad Shahid Khan via jianhe)
 
+    YARN-4347. Resource manager fails with Null pointer exception. (Jian He via wangda)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/RMAppImpl.java

@@ -1282,7 +1282,7 @@ public class RMAppImpl implements RMApp, Recoverable {
         || appState == RMAppState.KILLED;
   }
   
-  private RMAppState getRecoveredFinalState() {
+  public RMAppState getRecoveredFinalState() {
     return this.recoveredFinalState;
   }
 

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

@@ -81,6 +81,7 @@ import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppEvent;
 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;
@@ -1039,6 +1040,9 @@ public class RMAppAttemptImpl implements RMAppAttempt, Recoverable {
     @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.
@@ -1046,8 +1050,6 @@ public class RMAppAttemptImpl implements RMAppAttempt, Recoverable {
        */
       if (appAttempt.recoveredFinalState != null) {
         appAttempt.progress = 1.0f;
-        RMApp rmApp =appAttempt.rmContext.getRMApps().get(
-            appAttempt.getAppAttemptId().getApplicationId());
         // We will replay the final attempt only if last attempt is in final
         // state but application is not in final state.
         if (rmApp.getCurrentAppAttempt() == appAttempt
@@ -1060,7 +1062,24 @@ public class RMAppAttemptImpl implements RMAppAttempt, Recoverable {
               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
@@ -1094,6 +1113,7 @@ public class RMAppAttemptImpl implements RMAppAttempt, Recoverable {
     }
   }
 
+
   private void rememberTargetTransitions(RMAppAttemptEvent event,
       Object transitionToDo, RMAppAttemptState targetFinalState) {
     transitionTodo = transitionToDo;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/TestWorkPreservingRMRestart.java

@@ -60,6 +60,7 @@ import org.apache.hadoop.yarn.server.api.protocolrecords.NMContainerStatus;
 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.rmapp.RMApp;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppState;
@@ -1160,4 +1161,45 @@ public class TestWorkPreservingRMRestart extends ParameterizedSchedulerTestBase
     nm1.setResourceTrackerService(rm2.getResourceTrackerService());
     rm2.start();
   }
+
+  // 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());
+  }
 }