YARN-11219. [Federation] Add getAppActivities, getAppStatistics REST APIs for Router. (#4757)

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

@@ -18,6 +18,7 @@
 package org.apache.hadoop.yarn.server.resourcemanager.webapp.dao;
 
 import java.util.ArrayList;
+import java.util.Collection;
 
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
@@ -33,6 +34,10 @@ public class ApplicationStatisticsInfo {
   public ApplicationStatisticsInfo() {
   } // JAXB needs this
 
+  public ApplicationStatisticsInfo(Collection<StatisticsItemInfo> items) {
+    statItem.addAll(items);
+  }
+
   public void add(StatisticsItemInfo statItem) {
     this.statItem.add(statItem);
   }

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

@@ -41,6 +41,12 @@ public StatisticsItemInfo(
     this.count = count;
   }
 
+  public StatisticsItemInfo(StatisticsItemInfo info) {
+    this.state = info.state;
+    this.type = info.type;
+    this.count = info.count;
+  }
+
   public YarnApplicationState getState() {
     return state;
   }
@@ -53,4 +59,7 @@ public long getCount() {
     return count;
   }
 
+  public void setCount(long count) {
+    this.count = count;
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/webapp/FederationInterceptorREST.java

@@ -1129,13 +1129,50 @@ public AppActivitiesInfo getAppActivities(HttpServletRequest hsr,
       String appId, String time, Set<String> requestPriorities,
       Set<String> allocationRequestIds, String groupBy, String limit,
       Set<String> actions, boolean summarize) {
-    throw new NotImplementedException("Code is not implemented");
+
+    // Only verify the app_id,
+    // because the specific subCluster needs to be found according to the app_id,
+    // and other verifications are directly handed over to the corresponding subCluster RM
+    if (appId == null || appId.isEmpty()) {
+      throw new IllegalArgumentException("Parameter error, the appId is empty or null.");
+    }
+
+    try {
+      SubClusterInfo subClusterInfo = getHomeSubClusterInfoByAppId(appId);
+      DefaultRequestInterceptorREST interceptor = getOrCreateInterceptorForSubCluster(
+          subClusterInfo.getSubClusterId(), subClusterInfo.getRMWebServiceAddress());
+
+      final HttpServletRequest hsrCopy = clone(hsr);
+      return interceptor.getAppActivities(hsrCopy, appId, time, requestPriorities,
+          allocationRequestIds, groupBy, limit, actions, summarize);
+    } catch (IllegalArgumentException e) {
+      RouterServerUtil.logAndThrowRunTimeException(e, "Unable to get subCluster by appId: %s.",
+          appId);
+    } catch (YarnException e) {
+      RouterServerUtil.logAndThrowRunTimeException("getAppActivities Failed.", e);
+    }
+
+    return null;
   }
 
   @Override
   public ApplicationStatisticsInfo getAppStatistics(HttpServletRequest hsr,
       Set<String> stateQueries, Set<String> typeQueries) {
-    throw new NotImplementedException("Code is not implemented");
+    try {
+      Map<SubClusterId, SubClusterInfo> subClustersActive = getActiveSubclusters();
+      final HttpServletRequest hsrCopy = clone(hsr);
+      Class[] argsClasses = new Class[]{HttpServletRequest.class, Set.class, Set.class};
+      Object[] args = new Object[]{hsrCopy, stateQueries, typeQueries};
+      ClientMethod remoteMethod = new ClientMethod("getAppStatistics", argsClasses, args);
+      Map<SubClusterInfo, ApplicationStatisticsInfo> appStatisticsMap = invokeConcurrent(
+          subClustersActive.values(), remoteMethod, ApplicationStatisticsInfo.class);
+      return RouterWebServiceUtil.mergeApplicationStatisticsInfo(appStatisticsMap.values());
+    } catch (IOException e) {
+      RouterServerUtil.logAndThrowRunTimeException(e, "Get all active sub cluster(s) error.");
+    } catch (YarnException e) {
+      RouterServerUtil.logAndThrowRunTimeException(e, "getAppStatistics error.");
+    }
+    return null;
   }
 
   @Override

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/webapp/RouterWebServiceUtil.java

@@ -57,6 +57,8 @@
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.NodesInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.NodeLabelsInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.NodeToLabelsInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.ApplicationStatisticsInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.StatisticsItemInfo;
 import org.apache.hadoop.yarn.server.uam.UnmanagedApplicationManager;
 import org.apache.hadoop.yarn.webapp.BadRequestException;
 import org.apache.hadoop.yarn.webapp.ForbiddenException;
@@ -540,4 +542,38 @@ public static NodeToLabelsInfo mergeNodeToLabels(
 
     return new NodeToLabelsInfo(nodeToLabels);
   }
+
+  public static ApplicationStatisticsInfo mergeApplicationStatisticsInfo(
+      Collection<ApplicationStatisticsInfo> appStatistics) {
+    ApplicationStatisticsInfo result = new ApplicationStatisticsInfo();
+    Map<String, StatisticsItemInfo> statisticsItemMap = new HashMap<>();
+
+    appStatistics.stream().forEach(appStatistic -> {
+      List<StatisticsItemInfo> statisticsItemInfos = appStatistic.getStatItems();
+      for (StatisticsItemInfo statisticsItemInfo : statisticsItemInfos) {
+
+        String statisticsItemKey =
+            statisticsItemInfo.getType() + "_" + statisticsItemInfo.getState().toString();
+
+        StatisticsItemInfo statisticsItemValue;
+        if (statisticsItemMap.containsKey(statisticsItemKey)) {
+          statisticsItemValue = statisticsItemMap.get(statisticsItemKey);
+          long statisticsItemValueCount = statisticsItemValue.getCount();
+          long statisticsItemInfoCount = statisticsItemInfo.getCount();
+          long newCount = statisticsItemValueCount + statisticsItemInfoCount;
+          statisticsItemValue.setCount(newCount);
+        } else {
+          statisticsItemValue = new StatisticsItemInfo(statisticsItemInfo);
+        }
+
+        statisticsItemMap.put(statisticsItemKey, statisticsItemValue);
+      }
+    });
+
+    if (!statisticsItemMap.isEmpty()) {
+      result.getStatItems().addAll(statisticsItemMap.values());
+    }
+
+    return result;
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/test/java/org/apache/hadoop/yarn/server/router/webapp/MockDefaultRequestInterceptorREST.java

@@ -27,6 +27,8 @@
 import java.util.Collections;
 import java.util.Arrays;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -58,6 +60,20 @@
 import org.apache.hadoop.yarn.exceptions.ApplicationNotFoundException;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.server.federation.store.records.SubClusterId;
+import org.apache.hadoop.yarn.server.resourcemanager.RMContext;
+import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ActiveUsersManager;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerNode;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.activities.ActivitiesManager;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.activities.ActivitiesLogger;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.activities.ActivityDiagnosticConstant;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.activities.ActivityState;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.activities.ActivityLevel;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.LeafQueue;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.TestUtils;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.common.fica.FiCaSchedulerApp;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.common.fica.FiCaSchedulerNode;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.NodeIDsInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.NodeLabelsInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.LabelsToNodesInfo;
@@ -78,13 +94,22 @@
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppTimeoutsInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppPriority;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppQueue;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.StatisticsItemInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.ApplicationStatisticsInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppActivitiesInfo;
+import org.apache.hadoop.yarn.server.scheduler.SchedulerRequestKey;
 import org.apache.hadoop.yarn.server.webapp.dao.AppAttemptInfo;
 import org.apache.hadoop.yarn.server.webapp.dao.ContainerInfo;
 import org.apache.hadoop.yarn.server.webapp.dao.ContainersInfo;
+import org.apache.hadoop.yarn.util.SystemClock;
+import org.apache.hadoop.yarn.util.resource.Resources;
 import org.apache.hadoop.yarn.webapp.NotFoundException;
+import org.mockito.Mockito;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import static org.mockito.Mockito.mock;
+
 /**
  * This class mocks the RESTRequestInterceptor.
  */
@@ -132,8 +157,9 @@ public Response submitApplication(ApplicationSubmissionContextInfo newApp,
     // Initialize appReport
     ApplicationReport appReport = ApplicationReport.newInstance(
         appId, ApplicationAttemptId.newInstance(appId, 1), null, newApp.getQueue(), null, null, 0,
-        null, YarnApplicationState.ACCEPTED, "", null, 0, 0, null, null, null, 0, null, null, null,
+        null, YarnApplicationState.ACCEPTED, "", null, 0, 0, null, null, null, 0,
-        false, Priority.newInstance(newApp.getPriority()), null, null);
+        newApp.getApplicationType(), null, null, false, Priority.newInstance(newApp.getPriority()),
+        null, null);
 
     // Initialize appTimeoutsMap
     HashMap<ApplicationTimeoutType, ApplicationTimeout> appTimeoutsMap = new HashMap<>();
@@ -661,4 +687,105 @@ public Response updateAppQueue(AppQueue targetQueue, HttpServletRequest hsr, Str
     AppQueue targetAppQueue = new AppQueue(targetQueue.getQueue());
     return Response.status(Status.OK).entity(targetAppQueue).build();
   }
+
+  public void updateApplicationState(YarnApplicationState appState, String appId)
+      throws AuthorizationException, YarnException, InterruptedException, IOException {
+    validateRunning();
+    ApplicationId applicationId = ApplicationId.fromString(appId);
+    if (!applicationMap.containsKey(applicationId)) {
+      throw new NotFoundException("app with id: " + appId + " not found");
+    }
+    ApplicationReport appReport = applicationMap.get(applicationId);
+    appReport.setYarnApplicationState(appState);
+  }
+
+  @Override
+  public ApplicationStatisticsInfo getAppStatistics(
+      HttpServletRequest hsr, Set<String> stateQueries, Set<String> typeQueries) {
+    if (!isRunning) {
+      throw new RuntimeException("RM is stopped");
+    }
+
+    Map<String, StatisticsItemInfo> itemInfoMap = new HashMap<>();
+
+    for (ApplicationReport appReport : applicationMap.values()) {
+
+      YarnApplicationState appState = appReport.getYarnApplicationState();
+      String appType = appReport.getApplicationType();
+
+      if (stateQueries.contains(appState.name()) && typeQueries.contains(appType)) {
+        String itemInfoMapKey = appState.toString() + "_" + appType;
+        StatisticsItemInfo itemInfo = itemInfoMap.getOrDefault(itemInfoMapKey, null);
+        if (itemInfo == null) {
+          itemInfo = new StatisticsItemInfo(appState, appType, 1);
+        } else {
+          long newCount = itemInfo.getCount() + 1;
+          itemInfo.setCount(newCount);
+        }
+        itemInfoMap.put(itemInfoMapKey, itemInfo);
+      }
+    }
+
+    return new ApplicationStatisticsInfo(itemInfoMap.values());
+  }
+
+  @Override
+  public AppActivitiesInfo getAppActivities(
+      HttpServletRequest hsr, String appId, String time, Set<String> requestPriorities,
+      Set<String> allocationRequestIds, String groupBy, String limit, Set<String> actions,
+      boolean summarize) {
+    if (!isRunning) {
+      throw new RuntimeException("RM is stopped");
+    }
+
+    ApplicationId applicationId = ApplicationId.fromString(appId);
+    if (!applicationMap.containsKey(applicationId)) {
+      throw new NotFoundException("app with id: " + appId + " not found");
+    }
+
+    SchedulerNode schedulerNode = TestUtils.getMockNode("host0", "rack", 1, 10240);
+
+    RMContext rmContext = Mockito.mock(RMContext.class);
+    Mockito.when(rmContext.getYarnConfiguration()).thenReturn(this.getConf());
+    ResourceScheduler scheduler = Mockito.mock(ResourceScheduler.class);
+    Mockito.when(scheduler.getMinimumResourceCapability()).thenReturn(Resources.none());
+    Mockito.when(rmContext.getScheduler()).thenReturn(scheduler);
+    LeafQueue mockQueue = Mockito.mock(LeafQueue.class);
+    Map<ApplicationId, RMApp> rmApps = new ConcurrentHashMap<>();
+    Mockito.doReturn(rmApps).when(rmContext).getRMApps();
+
+    FiCaSchedulerNode node = (FiCaSchedulerNode) schedulerNode;
+    ApplicationAttemptId appAttemptId = ApplicationAttemptId.newInstance(applicationId, 0);
+    RMApp mockApp = Mockito.mock(RMApp.class);
+    Mockito.doReturn(appAttemptId.getApplicationId()).when(mockApp).getApplicationId();
+    Mockito.doReturn(FinalApplicationStatus.UNDEFINED).when(mockApp).getFinalApplicationStatus();
+    rmApps.put(appAttemptId.getApplicationId(), mockApp);
+    FiCaSchedulerApp app = new FiCaSchedulerApp(appAttemptId, "user", mockQueue,
+        mock(ActiveUsersManager.class), rmContext);
+
+    ActivitiesManager newActivitiesManager = new ActivitiesManager(rmContext);
+    newActivitiesManager.turnOnAppActivitiesRecording(app.getApplicationId(), 3);
+
+    int numActivities = 10;
+    for (int i = 0; i < numActivities; i++) {
+      ActivitiesLogger.APP.startAppAllocationRecording(newActivitiesManager, node,
+          SystemClock.getInstance().getTime(), app);
+      ActivitiesLogger.APP.recordAppActivityWithoutAllocation(newActivitiesManager, node, app,
+          new SchedulerRequestKey(Priority.newInstance(0), 0, null),
+          ActivityDiagnosticConstant.NODE_IS_BLACKLISTED, ActivityState.REJECTED,
+          ActivityLevel.NODE);
+      ActivitiesLogger.APP.finishSkippedAppAllocationRecording(newActivitiesManager,
+          app.getApplicationId(), ActivityState.SKIPPED, ActivityDiagnosticConstant.EMPTY);
+    }
+
+    Set<Integer> prioritiesInt =
+        requestPriorities.stream().map(pri -> Integer.parseInt(pri)).collect(Collectors.toSet());
+    Set<Long> allocationReqIds =
+        allocationRequestIds.stream().map(id -> Long.parseLong(id)).collect(Collectors.toSet());
+    AppActivitiesInfo appActivitiesInfo = newActivitiesManager.
+        getAppActivitiesInfo(app.getApplicationId(), prioritiesInt, allocationReqIds, null,
+        Integer.parseInt(limit), summarize, 3);
+
+    return appActivitiesInfo;
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/test/java/org/apache/hadoop/yarn/server/router/webapp/TestFederationInterceptorREST.java

@@ -23,6 +23,9 @@
 import java.util.List;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
+import java.util.HashSet;
+import java.util.Collections;
 
 import javax.ws.rs.core.Response;
 
@@ -33,6 +36,7 @@
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.NodeLabel;
 import org.apache.hadoop.yarn.api.records.ApplicationTimeoutType;
+import org.apache.hadoop.yarn.api.records.YarnApplicationState;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.server.federation.policies.manager.UniformBroadcastPolicyManager;
@@ -41,6 +45,9 @@
 import org.apache.hadoop.yarn.server.federation.store.records.SubClusterInfo;
 import org.apache.hadoop.yarn.server.federation.store.records.SubClusterRegisterRequest;
 import org.apache.hadoop.yarn.server.federation.store.records.SubClusterState;
+import org.apache.hadoop.yarn.server.federation.store.records.GetApplicationHomeSubClusterRequest;
+import org.apache.hadoop.yarn.server.federation.store.records.GetApplicationHomeSubClusterResponse;
+import org.apache.hadoop.yarn.server.federation.store.records.ApplicationHomeSubCluster;
 import org.apache.hadoop.yarn.server.federation.utils.FederationStateStoreFacade;
 import org.apache.hadoop.yarn.server.federation.utils.FederationStateStoreTestUtil;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppInfo;
@@ -61,9 +68,12 @@
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppAttemptInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppTimeoutInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppTimeoutsInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.StatisticsItemInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppPriority;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppQueue;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.NodeIDsInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.ApplicationStatisticsInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppActivitiesInfo;
 import org.apache.hadoop.yarn.server.webapp.dao.ContainerInfo;
 import org.apache.hadoop.yarn.server.webapp.dao.ContainersInfo;
 import org.apache.hadoop.yarn.util.MonotonicClock;
@@ -949,4 +959,73 @@ public void testGetAppQueue() throws IOException, InterruptedException, YarnExce
     Assert.assertNotNull(queue);
     Assert.assertEquals(queueName, queue.getQueue());
   }
+
+  @Test
+  public void testGetAppStatistics() throws IOException, InterruptedException, YarnException {
+    AppState appStateRUNNING = new AppState(YarnApplicationState.RUNNING.name());
+
+    // Submit application to multiSubCluster
+    ApplicationId appId = ApplicationId.newInstance(Time.now(), 1);
+    ApplicationSubmissionContextInfo context = new ApplicationSubmissionContextInfo();
+    context.setApplicationId(appId.toString());
+    context.setApplicationType("MapReduce");
+    context.setQueue("queue");
+
+    Assert.assertNotNull(interceptor.submitApplication(context, null));
+
+    GetApplicationHomeSubClusterRequest request =
+        GetApplicationHomeSubClusterRequest.newInstance(appId);
+    GetApplicationHomeSubClusterResponse response =
+        stateStore.getApplicationHomeSubCluster(request);
+
+    Assert.assertNotNull(response);
+    ApplicationHomeSubCluster homeSubCluster = response.getApplicationHomeSubCluster();
+
+    DefaultRequestInterceptorREST interceptorREST =
+        interceptor.getInterceptorForSubCluster(homeSubCluster.getHomeSubCluster());
+
+    MockDefaultRequestInterceptorREST mockInterceptorREST =
+        (MockDefaultRequestInterceptorREST) interceptorREST;
+    mockInterceptorREST.updateApplicationState(YarnApplicationState.RUNNING,
+        appId.toString());
+
+    Set<String> stateQueries = new HashSet<>();
+    stateQueries.add(YarnApplicationState.RUNNING.name());
+
+    Set<String> typeQueries = new HashSet<>();
+    typeQueries.add("MapReduce");
+
+    ApplicationStatisticsInfo response2 =
+        interceptor.getAppStatistics(null, stateQueries, typeQueries);
+
+    Assert.assertNotNull(response2);
+    Assert.assertFalse(response2.getStatItems().isEmpty());
+
+    StatisticsItemInfo result = response2.getStatItems().get(0);
+    Assert.assertEquals(1, result.getCount());
+    Assert.assertEquals(YarnApplicationState.RUNNING, result.getState());
+    Assert.assertEquals("MapReduce", result.getType());
+  }
+
+  @Test
+  public void testGetAppActivities() throws IOException, InterruptedException {
+    // Submit application to multiSubCluster
+    ApplicationId appId = ApplicationId.newInstance(Time.now(), 1);
+    ApplicationSubmissionContextInfo context = new ApplicationSubmissionContextInfo();
+    context.setApplicationId(appId.toString());
+    context.setApplicationType("MapReduce");
+    context.setQueue("queue");
+
+    Assert.assertNotNull(interceptor.submitApplication(context, null));
+    Set<String> prioritiesSet = Collections.singleton("0");
+    Set<String> allocationRequestIdsSet = Collections.singleton("0");
+
+    AppActivitiesInfo appActivitiesInfo =
+        interceptor.getAppActivities(null, appId.toString(), String.valueOf(Time.now()),
+        prioritiesSet, allocationRequestIdsSet, null, "-1", null, false);
+
+    Assert.assertNotNull(appActivitiesInfo);
+    Assert.assertEquals(appId.toString(), appActivitiesInfo.getApplicationId());
+    Assert.assertEquals(10, appActivitiesInfo.getAllocations().size());
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/test/java/org/apache/hadoop/yarn/server/router/webapp/TestRouterWebServiceUtil.java

@@ -31,6 +31,8 @@
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.NodesInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.ResourceRequestInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.AppAttemptInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.ApplicationStatisticsInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.StatisticsItemInfo;
 import org.apache.hadoop.yarn.server.uam.UnmanagedApplicationManager;
 import org.junit.Assert;
 import org.junit.Test;
@@ -592,4 +594,88 @@ public static AppAttemptInfo generateAppAttemptInfo(int attemptId) {
     when(appAttemptInfo.getLogsLink()).thenReturn("LogLink_" + attemptId);
     return appAttemptInfo;
   }
+
+  @Test
+  public void testMergeApplicationStatisticsInfo() {
+    ApplicationStatisticsInfo infoA = new ApplicationStatisticsInfo();
+    ApplicationStatisticsInfo infoB = new ApplicationStatisticsInfo();
+
+    StatisticsItemInfo item1 = new StatisticsItemInfo(YarnApplicationState.ACCEPTED, "*", 10);
+    StatisticsItemInfo item2 = new StatisticsItemInfo(YarnApplicationState.ACCEPTED, "*", 20);
+
+    infoA.add(item1);
+    infoB.add(item2);
+
+    List<ApplicationStatisticsInfo> lists = new ArrayList<>();
+    lists.add(infoA);
+    lists.add(infoB);
+
+    ApplicationStatisticsInfo mergeInfo =
+        RouterWebServiceUtil.mergeApplicationStatisticsInfo(lists);
+    ArrayList<StatisticsItemInfo> statItem = mergeInfo.getStatItems();
+
+    Assert.assertNotNull(statItem);
+    Assert.assertEquals(1, statItem.size());
+
+    StatisticsItemInfo first = statItem.get(0);
+
+    Assert.assertEquals(item1.getCount() + item2.getCount(), first.getCount());
+    Assert.assertEquals(item1.getType(), first.getType());
+    Assert.assertEquals(item1.getState(), first.getState());
+  }
+
+  @Test
+  public void testMergeDiffApplicationStatisticsInfo() {
+    ApplicationStatisticsInfo infoA = new ApplicationStatisticsInfo();
+    StatisticsItemInfo item1 = new StatisticsItemInfo(YarnApplicationState.ACCEPTED, "*", 10);
+    StatisticsItemInfo item2 =
+        new StatisticsItemInfo(YarnApplicationState.NEW_SAVING, "test1", 20);
+    infoA.add(item1);
+    infoA.add(item2);
+
+    ApplicationStatisticsInfo infoB = new ApplicationStatisticsInfo();
+    StatisticsItemInfo item3 =
+        new StatisticsItemInfo(YarnApplicationState.NEW_SAVING, "test1", 30);
+    StatisticsItemInfo item4 = new StatisticsItemInfo(YarnApplicationState.FINISHED, "test3", 40);
+    infoB.add(item3);
+    infoB.add(item4);
+
+    List<ApplicationStatisticsInfo> lists = new ArrayList<>();
+    lists.add(infoA);
+    lists.add(infoB);
+
+    ApplicationStatisticsInfo mergeInfo =
+        RouterWebServiceUtil.mergeApplicationStatisticsInfo(lists);
+
+    Assert.assertEquals(3, mergeInfo.getStatItems().size());
+    List<StatisticsItemInfo> mergeInfoStatItems = mergeInfo.getStatItems();
+
+    StatisticsItemInfo item1Result = null;
+    StatisticsItemInfo item2Result = null;
+    StatisticsItemInfo item3Result = null;
+
+    for (StatisticsItemInfo item : mergeInfoStatItems) {
+      // ACCEPTED
+      if (item.getState() == YarnApplicationState.ACCEPTED) {
+        item1Result = item;
+      }
+
+      // NEW_SAVING
+      if (item.getState() == YarnApplicationState.NEW_SAVING) {
+        item2Result = item;
+      }
+
+      // FINISHED
+      if (item.getState() == YarnApplicationState.FINISHED) {
+        item3Result = item;
+      }
+    }
+
+    Assert.assertEquals(YarnApplicationState.ACCEPTED, item1Result.getState());
+    Assert.assertEquals(item1.getCount(), item1Result.getCount());
+    Assert.assertEquals(YarnApplicationState.NEW_SAVING, item2Result.getState());
+    Assert.assertEquals((item2.getCount() + item3.getCount()), item2Result.getCount());
+    Assert.assertEquals(YarnApplicationState.FINISHED, item3Result.getState());
+    Assert.assertEquals(item4.getCount(), item3Result.getCount());
+  }
 }