YARN-3143. RM Apps REST API can return NPE or entries missing id and other fields. Contributed by Jason Lowe

(cherry picked from commit da2fb2bc46)

hadoop-yarn-project/CHANGES.txt

@@ -476,6 +476,9 @@ Release 2.7.0 - UNRELEASED
     YARN-3089. LinuxContainerExecutor does not handle file arguments to
     deleteAsUser (Eric Payne via jlowe)
 
+    YARN-3143. RM Apps REST API can return NPE or entries missing id and other
+    fields (jlowe)
+
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES

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

@@ -24,7 +24,6 @@
 import java.nio.ByteBuffer;
 import java.security.Principal;
 import java.security.PrivilegedExceptionAction;
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.EnumSet;
@@ -169,6 +168,12 @@ public RMWebServices(final ResourceManager rm, Configuration conf) {
     this.conf = conf;
   }
 
+  RMWebServices(ResourceManager rm, Configuration conf,
+      HttpServletResponse response) {
+    this(rm, conf);
+    this.response = response;
+  }
+
   protected Boolean hasAccess(RMApp app, HttpServletRequest hsr) {
     // Check for the authorization.
     UserGroupInformation callerUGI = getCallerUserGroupInformation(hsr, true);
@@ -459,6 +464,9 @@ public AppsInfo getApps(@Context HttpServletRequest hsr,
     AppsInfo allApps = new AppsInfo();
     for (ApplicationReport report : appReports) {
       RMApp rmapp = apps.get(report.getApplicationId());
+      if (rmapp == null) {
+        continue;
+      }
 
       if (finalStatusQuery != null && !finalStatusQuery.isEmpty()) {
         FinalApplicationStatus.valueOf(finalStatusQuery);

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

@@ -21,9 +21,18 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
+import static org.mockito.Matchers.anyBoolean;
+import static org.mockito.Matchers.isA;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 import java.io.StringReader;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Set;
 
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 import javax.ws.rs.core.MediaType;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
@@ -31,14 +40,21 @@
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.service.Service.STATE;
 import org.apache.hadoop.util.VersionInfo;
+import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationsRequest;
+import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationsResponse;
+import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.api.records.ApplicationReport;
 import org.apache.hadoop.yarn.api.records.QueueState;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.server.resourcemanager.ClientRMService;
 import org.apache.hadoop.yarn.server.resourcemanager.ClusterMetrics;
 import org.apache.hadoop.yarn.server.resourcemanager.MockRM;
+import org.apache.hadoop.yarn.server.resourcemanager.RMContextImpl;
 import org.apache.hadoop.yarn.server.resourcemanager.ResourceManager;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.QueueMetrics;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fifo.FifoScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppsInfo;
 import org.apache.hadoop.yarn.util.YarnVersionInfo;
 import org.apache.hadoop.yarn.webapp.GenericExceptionHandler;
 import org.apache.hadoop.yarn.webapp.JerseyTestBase;
@@ -586,4 +602,43 @@ public void verifyClusterSchedulerFifoGeneric(String type, String state,
 
   }
 
+  // Test the scenario where the RM removes an app just as we try to
+  // look at it in the apps list
+  @Test
+  public void testAppsRace() throws Exception {
+    // mock up an RM that returns app reports for apps that don't exist
+    // in the RMApps list
+    ApplicationId appId = ApplicationId.newInstance(1, 1);
+    ApplicationReport mockReport = mock(ApplicationReport.class);
+    when(mockReport.getApplicationId()).thenReturn(appId);
+    GetApplicationsResponse mockAppsResponse =
+        mock(GetApplicationsResponse.class);
+    when(mockAppsResponse.getApplicationList())
+      .thenReturn(Arrays.asList(new ApplicationReport[] { mockReport }));
+    ClientRMService mockClientSvc = mock(ClientRMService.class);
+    when(mockClientSvc.getApplications(isA(GetApplicationsRequest.class),
+        anyBoolean())).thenReturn(mockAppsResponse);
+    ResourceManager mockRM = mock(ResourceManager.class);
+    RMContextImpl rmContext = new RMContextImpl(null, null, null, null, null,
+        null, null, null, null, null);
+    when(mockRM.getRMContext()).thenReturn(rmContext);
+    when(mockRM.getClientRMService()).thenReturn(mockClientSvc);
+
+    RMWebServices webSvc = new RMWebServices(mockRM, new Configuration(),
+        mock(HttpServletResponse.class));
+
+    final Set<String> emptySet =
+        Collections.unmodifiableSet(Collections.<String>emptySet());
+
+    // verify we don't get any apps when querying
+    HttpServletRequest mockHsr = mock(HttpServletRequest.class);
+    AppsInfo appsInfo = webSvc.getApps(mockHsr, null, emptySet, null,
+        null, null, null, null, null, null, null, emptySet, emptySet);
+    assertTrue(appsInfo.getApps().isEmpty());
+
+    // verify we don't get an NPE when specifying a final status query
+    appsInfo = webSvc.getApps(mockHsr, null, emptySet, "FAILED",
+        null, null, null, null, null, null, null, emptySet, emptySet);
+    assertTrue(appsInfo.getApps().isEmpty());
+  }
 }