YARN-2405. NPE in FairSchedulerAppsBlock. (Tsuyoshi Ozawa via kasha)

hadoop-yarn-project/CHANGES.txt

@@ -249,6 +249,8 @@ Release 2.6.0 - UNRELEASED
     YARN-2035. FileSystemApplicationHistoryStore should not make working dir
     when it already exists. (Jonathan Eagles via zjshen)
 
+    YARN-2405. NPE in FairSchedulerAppsBlock. (Tsuyoshi Ozawa via kasha)
+
 Release 2.5.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/FairSchedulerAppsBlock.java

@@ -110,6 +110,10 @@ public class FairSchedulerAppsBlock extends HtmlBlock {
       String percent = String.format("%.1f", appInfo.getProgress());
       ApplicationAttemptId attemptId = app.getCurrentAppAttempt().getAppAttemptId();
       int fairShare = fsinfo.getAppFairShare(attemptId);
+      if (fairShare == FairSchedulerInfo.INVALID_FAIR_SHARE) {
+        // FairScheduler#applications don't have the entry. Skip it.
+        continue;
+      }
       //AppID numerical value parsed by parseHadoopID in yarn.dt.plugins.js
       appsTableData.append("[\"<a href='")
       .append(url("app", appInfo.getAppId())).append("'>")

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/FairSchedulerInfo.java

@@ -25,12 +25,14 @@ import javax.xml.bind.annotation.XmlTransient;
 import javax.xml.bind.annotation.XmlType;
 
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FSAppAttempt;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler;
 
 @XmlRootElement(name = "fairScheduler")
 @XmlType(name = "fairScheduler")
 @XmlAccessorType(XmlAccessType.FIELD)
 public class FairSchedulerInfo extends SchedulerInfo {
+  public static final int INVALID_FAIR_SHARE = -1;
   private FairSchedulerQueueInfo rootQueue;
   
   @XmlTransient
@@ -44,9 +46,18 @@ public class FairSchedulerInfo extends SchedulerInfo {
     rootQueue = new FairSchedulerQueueInfo(scheduler.getQueueManager().
         getRootQueue(), scheduler);
   }
-  
+
+  /**
+   * Get the fair share assigned to the appAttemptId.
+   * @param appAttemptId
+   * @return The fair share assigned to the appAttemptId,
+   * <code>FairSchedulerInfo#INVALID_FAIR_SHARE</code> if the scheduler does
+   * not know about this application attempt.
+   */
   public int getAppFairShare(ApplicationAttemptId appAttemptId) {
-    return scheduler.getSchedulerApp(appAttemptId).getFairShare().getMemory();
+    FSAppAttempt fsAppAttempt = scheduler.getSchedulerApp(appAttemptId);
+    return fsAppAttempt == null ?
+        INVALID_FAIR_SHARE :  fsAppAttempt.getFairShare().getMemory();
   }
   
   public FairSchedulerQueueInfo getRootQueueInfo() {

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

@@ -22,20 +22,29 @@ import com.google.common.collect.Maps;
 import com.google.inject.Binder;
 import com.google.inject.Injector;
 import com.google.inject.Module;
+import org.apache.hadoop.util.StringUtils;
+import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.api.records.Resource;
+import org.apache.hadoop.yarn.api.records.YarnApplicationState;
 import org.apache.hadoop.yarn.server.resourcemanager.RMContext;
 import org.apache.hadoop.yarn.server.resourcemanager.RMContextImpl;
 import org.apache.hadoop.yarn.server.resourcemanager.ResourceManager;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.MockRMApp;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
+import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppMetrics;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppState;
+import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.RMAppAttempt;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FSAppAttempt;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairSchedulerConfiguration;
 import org.apache.hadoop.yarn.server.resourcemanager.security.ClientToAMTokenSecretManagerInRM;
 import org.apache.hadoop.yarn.server.resourcemanager.security.NMTokenSecretManagerInRM;
 import org.apache.hadoop.yarn.server.resourcemanager.security.RMContainerTokenSecretManager;
 import org.apache.hadoop.yarn.webapp.test.WebAppTests;
+import org.junit.Assert;
 import org.junit.Test;
 
 import java.io.IOException;
@@ -75,12 +84,67 @@ public class TestRMWebAppFairScheduler {
     WebAppTests.flushOutput(injector);
   }
 
+
+  /**
+   *  Testing inconsistent state between AbstractYarnScheduler#applications and
+   *  RMContext#applications
+   */
+  @Test
+  public void testFairSchedulerWebAppPageInInconsistentState() {
+    List<RMAppState> appStates = Arrays.asList(
+        RMAppState.NEW,
+        RMAppState.NEW_SAVING,
+        RMAppState.SUBMITTED,
+        RMAppState.RUNNING,
+        RMAppState.FINAL_SAVING,
+        RMAppState.ACCEPTED,
+        RMAppState.FINISHED
+    );
+    final RMContext rmContext = mockRMContext(appStates);
+    Injector injector = WebAppTests.createMockInjector(RMContext.class,
+        rmContext,
+        new Module() {
+          @Override
+          public void configure(Binder binder) {
+            try {
+              ResourceManager mockRmWithFairScheduler =
+                  mockRmWithApps(rmContext);
+              binder.bind(ResourceManager.class).toInstance
+                  (mockRmWithFairScheduler);
+
+            } catch (IOException e) {
+              throw new IllegalStateException(e);
+            }
+          }
+        });
+    FairSchedulerPage fsViewInstance =
+        injector.getInstance(FairSchedulerPage.class);
+    try {
+      fsViewInstance.render();
+    } catch (Exception e) {
+      Assert.fail("Failed to render FairSchedulerPage: " +
+          StringUtils.stringifyException(e));
+    }
+    WebAppTests.flushOutput(injector);
+  }
+
   private static RMContext mockRMContext(List<RMAppState> states) {
     final ConcurrentMap<ApplicationId, RMApp> applicationsMaps = Maps
         .newConcurrentMap();
     int i = 0;
     for (RMAppState state : states) {
-      MockRMApp app = new MockRMApp(i, i, state);
+      MockRMApp app = new MockRMApp(i, i, state) {
+        @Override
+        public RMAppMetrics getRMAppMetrics() {
+          return new RMAppMetrics(Resource.newInstance(0, 0), 0, 0);
+        }
+        @Override
+        public YarnApplicationState createApplicationState() {
+          return YarnApplicationState.ACCEPTED;
+        }
+      };
+      RMAppAttempt attempt = mock(RMAppAttempt.class);
+      app.setCurrentAppAttempt(attempt);
       applicationsMaps.put(app.getApplicationId(), app);
       i++;
     }
@@ -113,4 +177,34 @@ public class TestRMWebAppFairScheduler {
     fs.init(conf);
     return fs;
   }
+
+  private static ResourceManager mockRmWithApps(RMContext rmContext) throws
+      IOException {
+    ResourceManager rm = mock(ResourceManager.class);
+    ResourceScheduler rs =  mockFairSchedulerWithoutApps(rmContext);
+    when(rm.getResourceScheduler()).thenReturn(rs);
+    when(rm.getRMContext()).thenReturn(rmContext);
+    return rm;
+  }
+
+  private static FairScheduler mockFairSchedulerWithoutApps(RMContext rmContext)
+      throws IOException {
+    FairScheduler fs = new FairScheduler() {
+      @Override
+      public FSAppAttempt getSchedulerApp(ApplicationAttemptId
+          applicationAttemptId) {
+        return null ;
+      }
+      @Override
+      public FSAppAttempt getApplicationAttempt(ApplicationAttemptId
+          applicationAttemptId) {
+        return null;
+      }
+    };
+    FairSchedulerConfiguration conf = new FairSchedulerConfiguration();
+    fs.setRMContext(rmContext);
+    fs.init(conf);
+    return fs;
+  }
+
 }