YARN-11531. [Federation] Code cleanup for NodeManager#amrmproxy. (#5841)

2023-07-20 02:50:38 +08:00 · 2023-07-20 02:50:38 +08:00 · 84dd624768
commit 84dd624768
parent b6b259066f
15 changed files with 670 additions and 820 deletions
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/federation/utils/FederationMethodWrapper.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/federation/utils/FederationMethodWrapper.java
@ -28,7 +28,7 @@ import java.util.Collection;
 public abstract class FederationMethodWrapper {

  /**
-   * List of parameters: static and dynamic values, matchings types.
+   * List of parameters: static and dynamic values, matching types.
   */
  private Object[] params;

--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AMRMProxyApplicationContext.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AMRMProxyApplicationContext.java
@ -67,7 +67,7 @@ public interface AMRMProxyApplicationContext {
   * Gets the NMContext object.
   * @return the NMContext.
   */
-  Context getNMCotext();
+  Context getNMContext();

  /**
   * Gets the credentials of this application.
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AMRMProxyApplicationContextImpl.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AMRMProxyApplicationContextImpl.java
@ -144,7 +144,7 @@ public class AMRMProxyApplicationContextImpl implements
  }

  @Override
-  public Context getNMCotext() {
+  public Context getNMContext() {
    return nmContext;
  }

--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AMRMProxyService.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AMRMProxyService.java
@ -741,7 +741,7 @@ public class AMRMProxyService extends CompositeService implements
            YarnConfiguration.AMRM_PROXY_INTERCEPTOR_CLASS_PIPELINE,
            YarnConfiguration.DEFAULT_AMRM_PROXY_INTERCEPTOR_CLASS_PIPELINE);

-    List<String> interceptorClassNames = new ArrayList<String>();
+    List<String> interceptorClassNames = new ArrayList<>();
    Collection<String> tempList =
        StringUtils.getStringCollection(configuredInterceptorClassNames);
    for (String item : tempList) {
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AMRMProxyTokenSecretManager.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AMRMProxyTokenSecretManager.java
@ -72,8 +72,7 @@ public class AMRMProxyTokenSecretManager extends

  private NMStateStoreService nmStateStore;

-  private final Set<ApplicationAttemptId> appAttemptSet =
-      new HashSet<ApplicationAttemptId>();
+  private final Set<ApplicationAttemptId> appAttemptSet = new HashSet<>();

  /**
   * Create an {@link AMRMProxyTokenSecretManager}.
@ -226,8 +225,7 @@ public class AMRMProxyTokenSecretManager extends
              .getMasterKey().getKeyId());
      byte[] password = this.createPassword(identifier);
      appAttemptSet.add(appAttemptId);
-      return new Token<AMRMTokenIdentifier>(identifier.getBytes(),
-          password, identifier.getKind(), new Text());
+      return new Token<>(identifier.getBytes(), password, identifier.getKind(), new Text());
    } finally {
      this.writeLock.unlock();
    }
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AbstractRequestInterceptor.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/AbstractRequestInterceptor.java
@ -159,9 +159,9 @@ public abstract class AbstractRequestInterceptor implements
   * @return the NMSS instance
   */
  public NMStateStoreService getNMStateStore() {
-    if (this.appContext == null || this.appContext.getNMCotext() == null) {
+    if (this.appContext == null || this.appContext.getNMContext() == null) {
      return null;
    }
-    return this.appContext.getNMCotext().getNMStateStore();
+    return this.appContext.getNMContext().getNMStateStore();
  }
 }
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/DefaultRequestInterceptor.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/DefaultRequestInterceptor.java
@ -95,25 +95,17 @@ public final class DefaultRequestInterceptor extends
  private ApplicationMasterProtocol createRMClient(
      AMRMProxyApplicationContext appContext, final Configuration conf)
      throws IOException, InterruptedException {
-    if (appContext.getNMCotext().isDistributedSchedulingEnabled()) {
-      return user.doAs(
-          new PrivilegedExceptionAction<DistributedSchedulingAMProtocol>() {
-            @Override
-            public DistributedSchedulingAMProtocol run() throws Exception {
-              setAMRMTokenService(conf);
-              return ServerRMProxy.createRMProxy(conf,
-                  DistributedSchedulingAMProtocol.class);
-            }
-          });
+    if (appContext.getNMContext().isDistributedSchedulingEnabled()) {
+      return user.doAs((PrivilegedExceptionAction<DistributedSchedulingAMProtocol>) () -> {
+        setAMRMTokenService(conf);
+        return ServerRMProxy.createRMProxy(conf, DistributedSchedulingAMProtocol.class);
+      });
    } else {
      return user.doAs(
-          new PrivilegedExceptionAction<ApplicationMasterProtocol>() {
-            @Override
-            public ApplicationMasterProtocol run() throws Exception {
-              setAMRMTokenService(conf);
-              return ClientRMProxy.createRMProxy(conf,
-                  ApplicationMasterProtocol.class);
-            }
+          (PrivilegedExceptionAction<ApplicationMasterProtocol>) () -> {
+            setAMRMTokenService(conf);
+            return ClientRMProxy.createRMProxy(conf,
+                ApplicationMasterProtocol.class);
          });
    }
  }
@ -144,7 +136,7 @@ public final class DefaultRequestInterceptor extends
  registerApplicationMasterForDistributedScheduling
      (RegisterApplicationMasterRequest request) throws YarnException,
      IOException {
-    if (getApplicationContext().getNMCotext()
+    if (getApplicationContext().getNMContext()
        .isDistributedSchedulingEnabled()) {
      LOG.info("Forwarding registerApplicationMasterForDistributedScheduling" +
          "request to the real YARN RM");
@ -161,7 +153,7 @@ public final class DefaultRequestInterceptor extends
      throws YarnException, IOException {
    LOG.debug("Forwarding allocateForDistributedScheduling request" +
        "to the real YARN RM");
-    if (getApplicationContext().getNMCotext()
+    if (getApplicationContext().getNMContext()
        .isDistributedSchedulingEnabled()) {
      DistributedSchedulingAllocateResponse allocateResponse =
          ((DistributedSchedulingAMProtocol)rmClient)
@ -197,7 +189,7 @@ public final class DefaultRequestInterceptor extends
  @VisibleForTesting
  public void setRMClient(final ApplicationMasterProtocol rmClient) {
    if (rmClient instanceof DistributedSchedulingAMProtocol) {
-      this.rmClient = (DistributedSchedulingAMProtocol)rmClient;
+      this.rmClient = rmClient;
    } else {
      this.rmClient = new DistributedSchedulingAMProtocol() {
        @Override
@ -254,7 +246,7 @@ public final class DefaultRequestInterceptor extends
      String defaultAddr, int defaultPort) {
    if (HAUtil.isHAEnabled(conf)) {
      // Build a list of service addresses to form the service name
-      ArrayList<String> services = new ArrayList<String>();
+      ArrayList<String> services = new ArrayList<>();
      YarnConfiguration yarnConf = new YarnConfiguration(conf);
      for (String rmId : HAUtil.getRMHAIds(conf)) {
        // Set RM_ID to get the corresponding RM_ADDRESS
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/FederationInterceptor.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/FederationInterceptor.java
@ -29,7 +29,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
-import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorCompletionService;
 import java.util.concurrent.ExecutorService;
@ -124,7 +123,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {

  /**
   * When AMRMProxy HA is enabled, secondary AMRMTokens will be stored in Yarn
-   * Registry. Otherwise if NM recovery is enabled, the UAM token are stored in
+   * Registry. Otherwise, if NM recovery is enabled, the UAM token are stored in
   * local NMSS instead under this directory name.
   */
  public static final String NMSS_SECONDARY_SC_PREFIX =
@ -150,7 +149,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
   */
  private AMRMClientRelayer homeRMRelayer;
  private SubClusterId homeSubClusterId;
-  private AMHeartbeatRequestHandler homeHeartbeartHandler;
+  private AMHeartbeatRequestHandler homeHeartbeatHandler;

  /**
   * UAM pool for secondary sub-clusters (ones other than home sub-cluster),
@ -162,20 +161,20 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
   * first time. AM heart beats to them are also handled asynchronously for
   * performance reasons.
   */
-  private UnmanagedAMPoolManager uamPool;
+  private final UnmanagedAMPoolManager uamPool;

  /**
   * The rmProxy relayers for secondary sub-clusters that keep track of all
   * pending requests.
   */
-  private Map<String, AMRMClientRelayer> secondaryRelayers;
+  private final Map<String, AMRMClientRelayer> secondaryRelayers;

  /**
   * Stores the AllocateResponses that are received asynchronously from all the
   * sub-cluster resource managers, including home RM, but not merged and
   * returned back to AM yet.
   */
-  private Map<SubClusterId, List<AllocateResponse>> asyncResponseSink;
+  private final Map<SubClusterId, List<AllocateResponse>> asyncResponseSink;

  /**
   * Remembers the last allocate response from all known sub-clusters. This is
@ -183,15 +182,15 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
   * cluster-wide info (e.g. AvailableResource, NumClusterNodes) in the allocate
   * response back to AM.
   */
-  private Map<SubClusterId, AllocateResponse> lastSCResponse;
+  private final Map<SubClusterId, AllocateResponse> lastSCResponse;

  /**
   * The async UAM registration result that is not consumed yet.
   */
-  private Map<SubClusterId, RegisterApplicationMasterResponse> uamRegistrations;
+  private final Map<SubClusterId, RegisterApplicationMasterResponse> uamRegistrations;

  // For unit test synchronization
-  private Map<SubClusterId, Future<?>> uamRegisterFutures;
+  private final Map<SubClusterId, Future<?>> uamRegisterFutures;

  /** Thread pool used for asynchronous operations. */
  private ExecutorService threadpool;
@ -216,7 +215,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
   * the container, so that we know which sub-cluster to forward later requests
   * about existing containers to.
   */
-  private Map<ContainerId, SubClusterId> containerIdToSubClusterIdMap;
+  private final Map<ContainerId, SubClusterId> containerIdToSubClusterIdMap;

  /**
   * The original registration request that was sent by the AM. This instance is
@ -259,7 +258,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {

  private boolean waitUamRegisterDone;

-  private MonotonicClock clock = new MonotonicClock();
+  private final MonotonicClock clock = new MonotonicClock();

  /**
   * Creates an instance of the FederationInterceptor class.
@ -324,11 +323,11 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
        ApplicationMasterProtocol.class, appOwner), appId,
        this.homeSubClusterId.toString());

-    this.homeHeartbeartHandler =
-        createHomeHeartbeartHandler(conf, appId, this.homeRMRelayer);
-    this.homeHeartbeartHandler.setUGI(appOwner);
-    this.homeHeartbeartHandler.setDaemon(true);
-    this.homeHeartbeartHandler.start();
+    this.homeHeartbeatHandler =
+        createHomeHeartbeatHandler(conf, appId, this.homeRMRelayer);
+    this.homeHeartbeatHandler.setUGI(appOwner);
+    this.homeHeartbeatHandler.setDaemon(true);
+    this.homeHeartbeatHandler.start();

    // set lastResponseId to -1 before application master registers
    this.lastAllocateResponse =
@ -852,7 +851,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
        this.homeRMRelayer.finishApplicationMaster(request);

    // Stop the home heartbeat thread
-    this.homeHeartbeartHandler.shutdown();
+    this.homeHeartbeatHandler.shutdown();

    if (failedToUnRegister) {
      homeResponse.setIsUnregistered(false);
@ -868,9 +867,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
  private boolean checkRequestFinalApplicationStatusSuccess(
      FinishApplicationMasterRequest request) {
    if (request != null && request.getFinalApplicationStatus() != null) {
-      if (request.getFinalApplicationStatus().equals(FinalApplicationStatus.SUCCEEDED)) {
-        return true;
-      }
+      return request.getFinalApplicationStatus().equals(FinalApplicationStatus.SUCCEEDED);
    }
    return false;
  }
@ -907,7 +904,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
    }

    // Stop the home heartbeat thread
-    this.homeHeartbeartHandler.shutdown();
+    this.homeHeartbeatHandler.shutdown();
    this.homeRMRelayer.shutdown();

    // Shutdown needs to clean up app
@ -946,12 +943,12 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
  }

  @VisibleForTesting
-  protected AMHeartbeatRequestHandler getHomeHeartbeartHandler() {
-    return this.homeHeartbeartHandler;
+  protected AMHeartbeatRequestHandler getHomeHeartbeatHandler() {
+    return this.homeHeartbeatHandler;
  }

  /**
-   * Create the UAM pool manager for secondary sub-clsuters. For unit test to
+   * Create the UAM pool manager for secondary sub-clusters. For unit test to
   * override.
   *
   * @param threadPool the thread pool to use
@ -964,7 +961,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
  }

  @VisibleForTesting
-  protected AMHeartbeatRequestHandler createHomeHeartbeartHandler(
+  protected AMHeartbeatRequestHandler createHomeHeartbeatHandler(
      Configuration conf, ApplicationId appId,
      AMRMClientRelayer rmProxyRelayer) {
    return new AMHeartbeatRequestHandler(conf, appId, rmProxyRelayer);
@ -1052,49 +1049,41 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
      final Token<AMRMTokenIdentifier> amrmToken = entry.getValue();

      completionService
-          .submit(new Callable<RegisterApplicationMasterResponse>() {
-            @Override
-            public RegisterApplicationMasterResponse call() throws Exception {
-              RegisterApplicationMasterResponse response = null;
-              try {
-                // Create a config loaded with federation on and subclusterId
-                // for each UAM
-                YarnConfiguration config = new YarnConfiguration(getConf());
-                FederationProxyProviderUtil.updateConfForFederation(config,
-                    subClusterId.getId());
+          .submit(() -> {
+            RegisterApplicationMasterResponse response = null;
+            try {
+              // Create a config loaded with federation on and subclusterId
+              // for each UAM
+              YarnConfiguration config = new YarnConfiguration(getConf());
+              FederationProxyProviderUtil.updateConfForFederation(config,
+                  subClusterId.getId());

-                ApplicationSubmissionContext originalSubmissionContext =
-                    federationFacade.getApplicationSubmissionContext(appId);
+              ApplicationSubmissionContext originalSubmissionContext =
+                  federationFacade.getApplicationSubmissionContext(appId);

-                uamPool.reAttachUAM(subClusterId.getId(), config, appId,
-                    amRegistrationResponse.getQueue(),
-                    getApplicationContext().getUser(), homeSubClusterId.getId(),
-                    amrmToken, subClusterId.toString(), originalSubmissionContext);
+              uamPool.reAttachUAM(subClusterId.getId(), config, appId,
+                  amRegistrationResponse.getQueue(),
+                  getApplicationContext().getUser(), homeSubClusterId.getId(),
+                  amrmToken, subClusterId.toString(), originalSubmissionContext);

-                secondaryRelayers.put(subClusterId.getId(),
-                    uamPool.getAMRMClientRelayer(subClusterId.getId()));
+              secondaryRelayers.put(subClusterId.getId(),
+                  uamPool.getAMRMClientRelayer(subClusterId.getId()));

-                response = uamPool.registerApplicationMaster(
-                    subClusterId.getId(), amRegistrationRequest);
+              response = uamPool.registerApplicationMaster(subClusterId.getId(),
+                  amRegistrationRequest);

-                // Set sub-cluster to be timed out initially
-                lastSCResponseTime.put(subClusterId,
-                    clock.getTime() - subClusterTimeOut);
+              // Set sub-cluster to be timed out initially
+              lastSCResponseTime.put(subClusterId, clock.getTime() - subClusterTimeOut);

-                if (response != null
-                    && response.getContainersFromPreviousAttempts() != null) {
-                  cacheAllocatedContainers(
-                      response.getContainersFromPreviousAttempts(),
-                      subClusterId);
-                }
-                LOG.info("UAM {} reattached for {}", subClusterId, appId);
-              } catch (Throwable e) {
-                LOG.error(
-                    "Reattaching UAM " + subClusterId + " failed for " + appId,
-                    e);
+              if (response != null && response.getContainersFromPreviousAttempts() != null) {
+                cacheAllocatedContainers(response.getContainersFromPreviousAttempts(),
+                    subClusterId);
              }
-              return response;
+              LOG.info("UAM {} reattached for {}", subClusterId, appId);
+            } catch (Throwable e) {
+              LOG.error("Reattaching UAM {} failed for {}.", subClusterId, appId, e);
            }
+            return response;
          });
    }

@ -1115,7 +1104,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
  }

  private SubClusterId getSubClusterForNode(String nodeName) {
-    SubClusterId subClusterId = null;
+    SubClusterId subClusterId;
    try {
      subClusterId = this.subClusterResolver.getSubClusterForNode(nodeName);
    } catch (YarnException e) {
@ -1139,8 +1128,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
   */
  private Map<SubClusterId, AllocateRequest> splitAllocateRequest(
      AllocateRequest request) throws YarnException {
-    Map<SubClusterId, AllocateRequest> requestMap =
-        new HashMap<SubClusterId, AllocateRequest>();
+    Map<SubClusterId, AllocateRequest> requestMap = new HashMap<>();

    // Create heart beat request for home sub-cluster resource manager
    findOrCreateAllocateRequestForSubCluster(this.homeSubClusterId, request,
@ -1230,8 +1218,8 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
   *
   * @param requests contains the heart beat requests to send to the resource
   *          manager keyed by the sub-cluster id
-   * @throws YarnException
-   * @throws IOException
+   * @throws YarnException exceptions from yarn servers.
+   * @throws IOException an I/O exception of some sort has occurred.
   */
  private void sendRequestsToResourceManagers(
      Map<SubClusterId, AllocateRequest> requests)
@ -1255,7 +1243,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {

      if (subClusterId.equals(this.homeSubClusterId)) {
        // Request for the home sub-cluster resource manager
-        this.homeHeartbeartHandler.allocateAsync(entry.getValue(),
+        this.homeHeartbeatHandler.allocateAsync(entry.getValue(),
            new HeartbeatCallBack(this.homeSubClusterId, false));
      } else {
        if (!this.uamPool.hasUAMId(subClusterId.getId())) {
@ -1280,7 +1268,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
    // list and create and register Unmanaged AM instance for the new ones
    List<SubClusterId> newSubClusters = new ArrayList<>();

-    requests.keySet().stream().forEach(subClusterId -> {
+    requests.keySet().forEach(subClusterId -> {
      String id = subClusterId.getId();
      if (!subClusterId.equals(this.homeSubClusterId) && !this.uamPool.hasUAMId(id)) {
        newSubClusters.add(subClusterId);
@ -1455,10 +1443,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
      List<ContainerStatus> finishedContainers) {
    for (ContainerStatus container : finishedContainers) {
      LOG.debug("Completed container {}", container);
-      if (containerIdToSubClusterIdMap
-          .containsKey(container.getContainerId())) {
-        containerIdToSubClusterIdMap.remove(container.getContainerId());
-      }
+      containerIdToSubClusterIdMap.remove(container.getContainerId());
    }
  }

@ -1697,7 +1682,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
  private static AllocateRequest findOrCreateAllocateRequestForSubCluster(
      SubClusterId subClusterId, AllocateRequest originalAMRequest,
      Map<SubClusterId, AllocateRequest> requestMap) {
-    AllocateRequest newRequest = null;
+    AllocateRequest newRequest;
    if (requestMap.containsKey(subClusterId)) {
      newRequest = requestMap.get(subClusterId);
    } else {
@ -1715,14 +1700,14 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
  private static AllocateRequest createAllocateRequest() {
    AllocateRequest request =
        RECORD_FACTORY.newRecordInstance(AllocateRequest.class);
-    request.setAskList(new ArrayList<ResourceRequest>());
-    request.setReleaseList(new ArrayList<ContainerId>());
+    request.setAskList(new ArrayList<>());
+    request.setReleaseList(new ArrayList<>());
    ResourceBlacklistRequest blackList =
        ResourceBlacklistRequest.newInstance(null, null);
-    blackList.setBlacklistAdditions(new ArrayList<String>());
-    blackList.setBlacklistRemovals(new ArrayList<String>());
+    blackList.setBlacklistAdditions(new ArrayList<>());
+    blackList.setBlacklistRemovals(new ArrayList<>());
    request.setResourceBlacklistRequest(blackList);
-    request.setUpdateRequests(new ArrayList<UpdateContainerRequest>());
+    request.setUpdateRequests(new ArrayList<>());
    return request;
  }

@ -1738,9 +1723,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
      long duration = this.clock.getTime() - entry.getValue();
      if (duration > this.subClusterTimeOut) {
        if (verbose) {
-          LOG.warn(
-              "Subcluster {} doesn't have a successful heartbeat"
-                  + " for {} seconds for {}",
+          LOG.warn("Subcluster {} doesn't have a successful heartbeat for {} seconds for {}",
              entry.getKey(), (double) duration / 1000, this.attemptId);
        }
        timedOutSCs.add(entry.getKey());
@ -1810,8 +1793,8 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
   * Async callback handler for heart beat response from all sub-clusters.
   */
  private class HeartbeatCallBack implements AsyncCallback<AllocateResponse> {
-    private SubClusterId subClusterId;
-    private boolean isUAM;
+    private final SubClusterId subClusterId;
+    private final boolean isUAM;

    HeartbeatCallBack(SubClusterId subClusterId, boolean isUAM) {
      this.subClusterId = subClusterId;
@ -1823,7 +1806,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
      org.apache.hadoop.yarn.api.records.Token amrmToken =
          response.getAMRMToken();
      synchronized (asyncResponseSink) {
-        List<AllocateResponse> responses = null;
+        List<AllocateResponse> responses;
        if (asyncResponseSink.containsKey(subClusterId)) {
          responses = asyncResponseSink.get(subClusterId);
        } else {
@ -1846,8 +1829,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
      try {
        policyInterpreter.notifyOfResponse(subClusterId, response);
      } catch (YarnException e) {
-        LOG.warn("notifyOfResponse for policy failed for sub-cluster "
-            + subClusterId, e);
+        LOG.warn("notifyOfResponse for policy failed for sub-cluster {}.", subClusterId, e);
      }

      // Save the new AMRMToken for the UAM if present
@ -1866,11 +1848,9 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
              AMRMTokenIdentifier identifier = new AMRMTokenIdentifier();
              identifier.readFields(new DataInputStream(
                  new ByteArrayInputStream(newToken.getIdentifier())));
-              LOG.info(
-                  "Received new UAM amrmToken with keyId {} and "
-                      + "service {} from {} for {}, written to Registry",
-                  identifier.getKeyId(), newToken.getService(), subClusterId,
-                  attemptId);
+              LOG.info("Received new UAM amrmToken with keyId {} and service {} from {} for {}, " +
+                  "written to Registry", identifier.getKeyId(), newToken.getService(),
+                  subClusterId, attemptId);
            } catch (IOException e) {
            }
          }
@ -1881,7 +1861,7 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
                newToken.encodeToUrlString().getBytes(STRING_TO_BYTE_FORMAT));
          } catch (IOException e) {
            LOG.error("Error storing UAM token as AMRMProxy "
-                + "context entry in NMSS for " + attemptId, e);
+                + "context entry in NMSS for {}.", attemptId, e);
          }
        }
      }
@ -1893,8 +1873,8 @@ public class FederationInterceptor extends AbstractRequestInterceptor {
   * FinishApplicationMasterResponse instances.
   */
  private static class FinishApplicationMasterResponseInfo {
-    private FinishApplicationMasterResponse response;
-    private String subClusterId;
+    private final FinishApplicationMasterResponse response;
+    private final String subClusterId;

    FinishApplicationMasterResponseInfo(
        FinishApplicationMasterResponse response, String subClusterId) {
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/scheduler/DistributedScheduler.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/scheduler/DistributedScheduler.java
@ -87,11 +87,11 @@ public final class DistributedScheduler extends AbstractRequestInterceptor {

  public void init(AMRMProxyApplicationContext applicationContext) {
    super.init(applicationContext);
-    initLocal(applicationContext.getNMCotext().getNodeStatusUpdater()
+    initLocal(applicationContext.getNMContext().getNodeStatusUpdater()
        .getRMIdentifier(),
        applicationContext.getApplicationAttemptId(),
-        applicationContext.getNMCotext().getContainerAllocator(),
-        applicationContext.getNMCotext().getNMTokenSecretManager(),
+        applicationContext.getNMContext().getContainerAllocator(),
+        applicationContext.getNMContext().getNMTokenSecretManager(),
        applicationContext.getUser());
  }

--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/BaseAMRMProxyTest.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/BaseAMRMProxyTest.java
@ -82,7 +82,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeSet;
-import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ExecutorCompletionService;
@ -103,8 +102,7 @@ public abstract class BaseAMRMProxyTest {
  private MockAMRMProxyService amrmProxyService;

  // Thread pool used for asynchronous operations
-  private static ExecutorService threadpool = Executors
-      .newCachedThreadPool();
+  private final ExecutorService threadpool = Executors.newCachedThreadPool();
  private Configuration conf;
  private AsyncDispatcher dispatcher;
  private Context nmContext;
@ -230,47 +228,37 @@ public abstract class BaseAMRMProxyTest {
  protected <T, R> List<R> runInParallel(List<T> testContexts,
      final Function<T, R> func) {
    ExecutorCompletionService<R> completionService =
-        new ExecutorCompletionService<R>(this.getThreadPool());
-    LOG.info("Sending requests to endpoints asynchronously. Number of test contexts="
-        + testContexts.size());
-    for (int index = 0; index < testContexts.size(); index++) {
-      final T testContext = testContexts.get(index);
+        new ExecutorCompletionService<>(this.getThreadPool());
+    LOG.info("Sending requests to endpoints asynchronously. Number of test contexts = {}.",
+        testContexts.size());
+    for (final T testContext : testContexts) {
+      LOG.info("Adding request to threadpool for test context: {}.", testContext.toString());

-      LOG.info("Adding request to threadpool for test context: "
-          + testContext.toString());
+      completionService.submit(() -> {
+        LOG.info("Sending request. Test context: {}.", testContext);

-      completionService.submit(new Callable<R>() {
-        @Override
-        public R call() throws Exception {
-          LOG.info("Sending request. Test context:"
-              + testContext.toString());
-
-          R response = null;
-          try {
-            response = func.invoke(testContext);
-            LOG.info("Successfully sent request for context: "
-                + testContext.toString());
-          } catch (Throwable ex) {
-            LOG.error("Failed to process request for context: "
-                + testContext);
-            response = null;
-          }
-
-          return response;
+        R response;
+        try {
+          response = func.invoke(testContext);
+          LOG.info("Successfully sent request for context: {}.", testContext);
+        } catch (Throwable ex) {
+          LOG.error("Failed to process request for context: {}.", testContext);
+          response = null;
        }
+
+        return response;
      });
    }

-    ArrayList<R> responseList = new ArrayList<R>();
-    LOG.info("Waiting for responses from endpoints. Number of contexts="
-        + testContexts.size());
+    ArrayList<R> responseList = new ArrayList<>();
+    LOG.info("Waiting for responses from endpoints. Number of contexts = {}.", testContexts.size());
    for (int i = 0; i < testContexts.size(); ++i) {
      try {
        final Future<R> future = completionService.take();
        final R response = future.get(3000, TimeUnit.MILLISECONDS);
        responseList.add(response);
      } catch (Throwable e) {
-        LOG.error("Failed to process request " + e.getMessage());
+        LOG.error("Failed to process request {}", e.getMessage());
      }
    }

@ -291,29 +279,19 @@ public abstract class BaseAMRMProxyTest {
      final int testAppId) throws Exception, YarnException, IOException {
    final ApplicationUserInfo ugi = getApplicationUserInfo(testAppId);

-    return ugi
-        .getUser()
-        .doAs(
-            new PrivilegedExceptionAction<RegisterApplicationMasterResponse>() {
-              @Override
-              public RegisterApplicationMasterResponse run()
-                  throws Exception {
-                getAMRMProxyService().initApp(
-                    ugi.getAppAttemptId(),
-                    ugi.getUser().getUserName());
+    return ugi.getUser().doAs((PrivilegedExceptionAction<RegisterApplicationMasterResponse>) () -> {
+      getAMRMProxyService().initApp(ugi.getAppAttemptId(), ugi.getUser().getUserName());

-                final RegisterApplicationMasterRequest req =
-                    Records
-                        .newRecord(RegisterApplicationMasterRequest.class);
-                req.setHost(Integer.toString(testAppId));
-                req.setRpcPort(testAppId);
-                req.setTrackingUrl("");
+      final RegisterApplicationMasterRequest req =
+          Records.newRecord(RegisterApplicationMasterRequest.class);
+      req.setHost(Integer.toString(testAppId));
+      req.setRpcPort(testAppId);
+      req.setTrackingUrl("");

-                RegisterApplicationMasterResponse response =
-                    getAMRMProxyService().registerApplicationMaster(req);
-                return response;
-              }
-            });
+      RegisterApplicationMasterResponse response =
+          getAMRMProxyService().registerApplicationMaster(req);
+      return response;
+    });
  }

  /**
@ -327,37 +305,30 @@ public abstract class BaseAMRMProxyTest {
      final ArrayList<T> testContexts) {
    List<RegisterApplicationMasterResponseInfo<T>> responses =
        runInParallel(testContexts,
-            new Function<T, RegisterApplicationMasterResponseInfo<T>>() {
-              @Override
-              public RegisterApplicationMasterResponseInfo<T> invoke(
-                  T testContext) {
-                RegisterApplicationMasterResponseInfo<T> response = null;
-                try {
-                  int index = testContexts.indexOf(testContext);
-                  response =
-                      new RegisterApplicationMasterResponseInfo<T>(
-                          registerApplicationMaster(index), testContext);
-                  Assert.assertNotNull(response.getResponse());
-                  Assert.assertEquals(Integer.toString(index), response
-                      .getResponse().getQueue());
+          testContext -> {
+            RegisterApplicationMasterResponseInfo<T> response;
+            try {
+              int index = testContexts.indexOf(testContext);
+              response = new RegisterApplicationMasterResponseInfo<>(
+                  registerApplicationMaster(index), testContext);
+              Assert.assertNotNull(response.getResponse());
+              Assert.assertEquals(Integer.toString(index), response.getResponse().getQueue());

-                  LOG.info("Successfully registered application master with test context: "
-                      + testContext);
-                } catch (Throwable ex) {
-                  response = null;
-                  LOG.error("Failed to register application master with test context: "
-                      + testContext);
-                }
+              LOG.info("Successfully registered application master with test context: {}.",
+                  testContext);
+            } catch (Throwable ex) {
+              response = null;
+              LOG.error("Failed to register application master with test context: {}.",
+                  testContext);
+            }

-                return response;
-              }
-            });
+            return response;
+          });

-    Assert.assertEquals(
-        "Number of responses received does not match with request",
+    Assert.assertEquals("Number of responses received does not match with request",
        testContexts.size(), responses.size());

-    Set<T> contextResponses = new TreeSet<T>();
+    Set<T> contextResponses = new TreeSet<>();
    for (RegisterApplicationMasterResponseInfo<T> item : responses) {
      contextResponses.add(item.getTestContext());
    }
@ -410,37 +381,28 @@ public abstract class BaseAMRMProxyTest {
      final ArrayList<T> testContexts) {
    List<FinishApplicationMasterResponseInfo<T>> responses =
        runInParallel(testContexts,
-            new Function<T, FinishApplicationMasterResponseInfo<T>>() {
-              @Override
-              public FinishApplicationMasterResponseInfo<T> invoke(
-                  T testContext) {
-                FinishApplicationMasterResponseInfo<T> response = null;
-                try {
-                  response =
-                      new FinishApplicationMasterResponseInfo<T>(
-                          finishApplicationMaster(
-                              testContexts.indexOf(testContext),
-                              FinalApplicationStatus.SUCCEEDED),
-                          testContext);
-                  Assert.assertNotNull(response.getResponse());
+            testContext -> {
+              FinishApplicationMasterResponseInfo<T> response;
+              try {
+                response = new FinishApplicationMasterResponseInfo<>(
+                    finishApplicationMaster(testContexts.indexOf(testContext),
+                    FinalApplicationStatus.SUCCEEDED), testContext);
+                Assert.assertNotNull(response.getResponse());

-                  LOG.info("Successfully finished application master with test contexts: "
-                      + testContext);
-                } catch (Throwable ex) {
-                  response = null;
-                  LOG.error("Failed to finish application master with test context: "
-                      + testContext);
-                }
-
-                return response;
+                LOG.info("Successfully finished application master with test contexts: {}.",
+                    testContext);
+              } catch (Throwable ex) {
+                response = null;
+                LOG.error("Failed to finish application master with test context: {}.",
+                    testContext);
              }
+              return response;
            });

-    Assert.assertEquals(
-        "Number of responses received does not match with request",
+    Assert.assertEquals("Number of responses received does not match with request",
        testContexts.size(), responses.size());

-    Set<T> contextResponses = new TreeSet<T>();
+    Set<T> contextResponses = new TreeSet<>();
    for (FinishApplicationMasterResponseInfo<T> item : responses) {
      Assert.assertNotNull(item);
      Assert.assertNotNull(item.getResponse());
@ -455,27 +417,19 @@ public abstract class BaseAMRMProxyTest {
  }

  protected AllocateResponse allocate(final int testAppId)
-      throws Exception, YarnException, IOException {
+      throws Exception {
    final AllocateRequest req = Records.newRecord(AllocateRequest.class);
    req.setResponseId(testAppId);
    return allocate(testAppId, req);
  }

-  protected AllocateResponse allocate(final int testAppId,
-      final AllocateRequest request) throws Exception, YarnException,
-      IOException {
+  protected AllocateResponse allocate(final int testAppId, final AllocateRequest request)
+      throws Exception {

    final ApplicationUserInfo ugi = getApplicationUserInfo(testAppId);

-    return ugi.getUser().doAs(
-        new PrivilegedExceptionAction<AllocateResponse>() {
-          @Override
-          public AllocateResponse run() throws Exception {
-            AllocateResponse response =
-                getAMRMProxyService().allocate(request);
-            return response;
-          }
-        });
+    return ugi.getUser().doAs((PrivilegedExceptionAction<AllocateResponse>)
+        () -> getAMRMProxyService().allocate(request));
  }

  protected ApplicationUserInfo getApplicationUserInfo(final int testAppId) {
@ -490,44 +444,37 @@ public abstract class BaseAMRMProxyTest {
  }

  protected List<ResourceRequest> createResourceRequests(String[] hosts,
-      int memory, int vCores, int priority, int containers)
-      throws Exception {
+      int memory, int vCores, int priority, int containers) {
    return createResourceRequests(hosts, memory, vCores, priority,
        containers, null);
  }

  protected List<ResourceRequest> createResourceRequests(String[] hosts,
-      int memory, int vCores, int priority, int containers,
-      String labelExpression) throws Exception {
-    List<ResourceRequest> reqs = new ArrayList<ResourceRequest>();
+      int memory, int vCores, int priority, int containers, String labelExpression) {
+    List<ResourceRequest> reqs = new ArrayList<>();
    for (String host : hosts) {
-      ResourceRequest hostReq =
-          createResourceRequest(host, memory, vCores, priority,
-              containers, labelExpression);
+      ResourceRequest hostReq = createResourceRequest(host, memory, vCores, priority,
+          containers, labelExpression);
      reqs.add(hostReq);
-      ResourceRequest rackReq =
-          createResourceRequest("/default-rack", memory, vCores, priority,
-              containers, labelExpression);
+      ResourceRequest rackReq = createResourceRequest("/default-rack", memory, vCores, priority,
+          containers, labelExpression);
      reqs.add(rackReq);
    }

-    ResourceRequest offRackReq =
-        createResourceRequest(ResourceRequest.ANY, memory, vCores,
-            priority, containers, labelExpression);
+    ResourceRequest offRackReq = createResourceRequest(ResourceRequest.ANY, memory, vCores,
+        priority, containers, labelExpression);
    reqs.add(offRackReq);
    return reqs;
  }

  protected ResourceRequest createResourceRequest(String resource,
-      int memory, int vCores, int priority, int containers)
-      throws Exception {
-    return createResourceRequest(resource, memory, vCores, priority,
-        containers, null);
+      int memory, int vCores, int priority, int containers) {
+    return createResourceRequest(resource, memory, vCores, priority, containers, null);
  }

  protected ResourceRequest createResourceRequest(String resource,
      int memory, int vCores, int priority, int containers,
-      String labelExpression) throws Exception {
+      String labelExpression) {
    ResourceRequest req = Records.newRecord(ResourceRequest.class);
    req.setResourceName(resource);
    req.setNumContainers(containers);
@ -548,8 +495,8 @@ public abstract class BaseAMRMProxyTest {
  /**
   * Returns an ApplicationId with the specified identifier
   * 
-   * @param testAppId
-   * @return
+   * @param testAppId testApplication.
+   * @return ApplicationId.
   */
  protected ApplicationId getApplicationId(int testAppId) {
    return ApplicationId.newInstance(123456, testAppId);
@ -559,8 +506,8 @@ public abstract class BaseAMRMProxyTest {
   * Return an instance of ApplicationAttemptId using specified identifier. This
   * identifier will be used for the ApplicationId too.
   * 
-   * @param testAppId
-   * @return
+   * @param testAppId testApplicationId.
+   * @return ApplicationAttemptId.
   */
  protected ApplicationAttemptId getApplicationAttemptId(int testAppId) {
    return ApplicationAttemptId.newInstance(getApplicationId(testAppId),
@ -571,8 +518,8 @@ public abstract class BaseAMRMProxyTest {
   * Return an instance of ApplicationAttemptId using specified identifier and
   * application id
   * 
-   * @param testAppId
-   * @return
+   * @param testAppId testApplicationId.
+   * @return ApplicationAttemptId.
   */
  protected ApplicationAttemptId getApplicationAttemptId(int testAppId,
      ApplicationId appId) {
@ -580,8 +527,8 @@ public abstract class BaseAMRMProxyTest {
  }

  protected static class RegisterApplicationMasterResponseInfo<T> {
-    private RegisterApplicationMasterResponse response;
-    private T testContext;
+    private final RegisterApplicationMasterResponse response;
+    private final T testContext;

    RegisterApplicationMasterResponseInfo(
        RegisterApplicationMasterResponse response, T testContext) {
@ -599,8 +546,8 @@ public abstract class BaseAMRMProxyTest {
  }

  protected static class FinishApplicationMasterResponseInfo<T> {
-    private FinishApplicationMasterResponse response;
-    private T testContext;
+    private final FinishApplicationMasterResponse response;
+    private final T testContext;

    FinishApplicationMasterResponseInfo(
        FinishApplicationMasterResponse response, T testContext) {
@ -618,8 +565,8 @@ public abstract class BaseAMRMProxyTest {
  }

  protected static class ApplicationUserInfo {
-    private UserGroupInformation user;
-    private ApplicationAttemptId attemptId;
+    private final UserGroupInformation user;
+    private final ApplicationAttemptId attemptId;

    ApplicationUserInfo(UserGroupInformation user,
        ApplicationAttemptId attemptId) {
@ -654,12 +601,12 @@ public abstract class BaseAMRMProxyTest {
     * actual service, the initialization is called by the
     * ContainerManagerImpl::StartContainers method
     * 
-     * @param applicationId
-     * @param user
+     * @param applicationId ApplicationAttemptId
+     * @param user username.
     */
    public void initApp(ApplicationAttemptId applicationId, String user) {
      super.initializePipeline(applicationId, user,
-          new Token<AMRMTokenIdentifier>(), null, null, false, null);
+          new Token<>(), null, null, false, null);
    }

    public void stopApp(ApplicationId applicationId) {
@ -672,7 +619,7 @@ public abstract class BaseAMRMProxyTest {
   * invoked asynchronously at a later point.
   */
  protected interface Function<T, R> {
-    public R invoke(T input);
+    R invoke(T input);
  }

  protected class NullContext implements Context {
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestAMRMProxyMetrics.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestAMRMProxyMetrics.java
@ -86,7 +86,7 @@ public class TestAMRMProxyMetrics extends BaseAMRMProxyTest {
        finishApplicationMaster(testAppId, FinalApplicationStatus.SUCCEEDED);

    Assert.assertNotNull(finishResponse);
-    Assert.assertEquals(true, finishResponse.getIsUnregistered());
+    Assert.assertTrue(finishResponse.getIsUnregistered());

    Assert.assertEquals(failedAppStartRequests, metrics.getFailedAppStartRequests());
    Assert.assertEquals(failedRegisterAMRequests, metrics.getFailedRegisterAMRequests());
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestAMRMProxyService.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestAMRMProxyService.java
@ -41,7 +41,6 @@ import org.apache.hadoop.yarn.api.records.FinalApplicationStatus;
 import org.apache.hadoop.yarn.api.records.ResourceRequest;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
-import org.apache.hadoop.yarn.security.AMRMTokenIdentifier;
 import org.apache.hadoop.yarn.server.MockResourceManagerFacade;
 import org.apache.hadoop.yarn.server.nodemanager.amrmproxy.AMRMProxyService.RequestInterceptorChainWrapper;
 import org.apache.hadoop.yarn.server.nodemanager.recovery.NMStateStoreService.RecoveredAMRMProxyState;
@ -58,6 +57,8 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {

  /**
   * Test if the pipeline is created properly.
+   *
+   * @throws Exception There was an error registerApplicationMaster.
   */
  @Test
  public void testRequestInterceptorChainCreation() throws Exception {
@ -73,8 +74,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
            root.getClass().getName());
        break;
      case 3:
-        Assert.assertEquals(MockRequestInterceptor.class.getName(), root
-            .getClass().getName());
+        Assert.assertEquals(MockRequestInterceptor.class.getName(), root.getClass().getName());
        break;
      }

@ -82,8 +82,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
      index++;
    }

-    Assert.assertEquals(
-        "The number of interceptors in chain does not match",
+    Assert.assertEquals("The number of interceptors in chain does not match",
        Integer.toString(4), Integer.toString(index));

  }
@ -91,7 +90,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
  /**
   * Tests registration of a single application master.
   * 
-   * @throws Exception
+   * @throws Exception There was an error registerApplicationMaster.
   */
  @Test
  public void testRegisterOneApplicationMaster() throws Exception {
@ -99,8 +98,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
    // manager return it as the queue name. Assert that we received the queue
    // name
    int testAppId = 1;
-    RegisterApplicationMasterResponse response1 =
-        registerApplicationMaster(testAppId);
+    RegisterApplicationMasterResponse response1 = registerApplicationMaster(testAppId);
    Assert.assertNotNull(response1);
    Assert.assertEquals(Integer.toString(testAppId), response1.getQueue());
  }
@ -108,7 +106,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
  /**
   * Tests the case when interceptor pipeline initialization fails.
   *
-   * @throws IOException
+   * @throws IOException There was an error registerApplicationMaster.
   */
  @Test
  public void testInterceptorInitFailure() throws IOException {
@ -127,9 +125,8 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
      Map<ApplicationId, RequestInterceptorChainWrapper> pipelines =
          getAMRMProxyService().getPipelines();
      ApplicationId id = getApplicationId(testAppId);
-      Assert.assertTrue(
-          "The interceptor pipeline should be removed if initialization fails",
-          pipelines.get(id) == null);
+      Assert.assertNull("The interceptor pipeline should be removed if initialization fails",
+          pipelines.get(id));
    }
  }

@ -137,28 +134,24 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
   * Tests the registration of multiple application master serially one at a
   * time.
   * 
-   * @throws Exception
+   * @throws Exception There was an error registerApplicationMaster.
   */
  @Test
  public void testRegisterMultipleApplicationMasters() throws Exception {
    for (int testAppId = 0; testAppId < 3; testAppId++) {
-      RegisterApplicationMasterResponse response =
-          registerApplicationMaster(testAppId);
+      RegisterApplicationMasterResponse response = registerApplicationMaster(testAppId);
      Assert.assertNotNull(response);
-      Assert
-          .assertEquals(Integer.toString(testAppId), response.getQueue());
+      Assert.assertEquals(Integer.toString(testAppId), response.getQueue());
    }
  }

  /**
   * Tests the registration of multiple application masters using multiple
   * threads in parallel.
-   * 
-   * @throws Exception
+   *
   */
  @Test
-  public void testRegisterMultipleApplicationMastersInParallel()
-      throws Exception {
+  public void testRegisterMultipleApplicationMastersInParallel() {
    int numberOfRequests = 5;
    ArrayList<String> testContexts =
        CreateTestRequestIdentifiers(numberOfRequests);
@ -167,10 +160,10 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {

  private ArrayList<String> CreateTestRequestIdentifiers(
      int numberOfRequests) {
-    ArrayList<String> testContexts = new ArrayList<String>();
+    ArrayList<String> testContexts = new ArrayList<>();
    LOG.info("Creating " + numberOfRequests + " contexts for testing");
    for (int ep = 0; ep < numberOfRequests; ep++) {
-      testContexts.add("test-endpoint-" + Integer.toString(ep));
+      testContexts.add("test-endpoint-" + ep);
      LOG.info("Created test context: " + testContexts.get(ep));
    }
    return testContexts;
@ -190,7 +183,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
            FinalApplicationStatus.SUCCEEDED);

    Assert.assertNotNull(finishResponse);
-    Assert.assertEquals(true, finishResponse.getIsUnregistered());
+    Assert.assertTrue(finishResponse.getIsUnregistered());
  }

  @Test
@ -219,7 +212,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
  }

  @Test
-  public void testFinishInvalidApplicationMaster() throws Exception {
+  public void testFinishInvalidApplicationMaster() {
    try {
      // Try to finish an application master that was not registered.
      finishApplicationMaster(4, FinalApplicationStatus.SUCCEEDED);
@ -248,11 +241,10 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
          finishApplicationMaster(index, FinalApplicationStatus.SUCCEEDED);

      Assert.assertNotNull(finishResponse);
-      Assert.assertEquals(true, finishResponse.getIsUnregistered());
+      Assert.assertTrue(finishResponse.getIsUnregistered());

      // Assert that the application has been removed from the collection
-      Assert.assertTrue(this.getAMRMProxyService()
-          .getPipelines().size() == index);
+      Assert.assertEquals(this.getAMRMProxyService().getPipelines().size(), index);
    }

    try {
@ -280,10 +272,10 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
  public void testFinishMultipleApplicationMastersInParallel()
      throws Exception {
    int numberOfRequests = 5;
-    ArrayList<String> testContexts = new ArrayList<String>();
-    LOG.info("Creating " + numberOfRequests + " contexts for testing");
+    ArrayList<String> testContexts = new ArrayList<>();
+    LOG.info("Creating {} contexts for testing", numberOfRequests);
    for (int i = 0; i < numberOfRequests; i++) {
-      testContexts.add("test-endpoint-" + Integer.toString(i));
+      testContexts.add("test-endpoint-" + i);
      LOG.info("Created test context: " + testContexts.get(i));

      RegisterApplicationMasterResponse registerResponse =
@ -313,11 +305,11 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
            FinalApplicationStatus.SUCCEEDED);

    Assert.assertNotNull(finishResponse);
-    Assert.assertEquals(true, finishResponse.getIsUnregistered());
+    Assert.assertTrue(finishResponse.getIsUnregistered());
  }

  @Test
-  public void testAllocateRequestWithoutRegistering() throws Exception {
+  public void testAllocateRequestWithoutRegistering() {

    try {
      // Try to allocate an application master without registering.
@ -381,51 +373,41 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
  public void testAllocateAndReleaseContainersForMultipleAMInParallel()
      throws Exception {
    int numberOfApps = 6;
-    ArrayList<Integer> tempAppIds = new ArrayList<Integer>();
+    ArrayList<Integer> tempAppIds = new ArrayList<>();
    for (int i = 0; i < numberOfApps; i++) {
-      tempAppIds.add(new Integer(i));
+      tempAppIds.add(i);
    }

-    final ArrayList<Integer> appIds = tempAppIds;
    List<Integer> responses =
-        runInParallel(appIds, new Function<Integer, Integer>() {
-          @Override
-          public Integer invoke(Integer testAppId) {
-            try {
-              RegisterApplicationMasterResponse registerResponse =
-                  registerApplicationMaster(testAppId);
-              Assert.assertNotNull("response is null", registerResponse);
-              List<Container> containers =
-                  getContainersAndAssert(testAppId, 10);
-              releaseContainersAndAssert(testAppId, containers);
+        runInParallel(tempAppIds, testAppId -> {
+          try {
+            RegisterApplicationMasterResponse registerResponse =
+                registerApplicationMaster(testAppId);
+            Assert.assertNotNull("response is null", registerResponse);
+            List<Container> containers =
+                getContainersAndAssert(testAppId, 10);
+            releaseContainersAndAssert(testAppId, containers);

-              LOG.info("Successfully registered application master with appId: "
-                  + testAppId);
-            } catch (Throwable ex) {
-              LOG.error(
-                  "Failed to register application master with appId: "
-                      + testAppId, ex);
-              testAppId = null;
-            }
-
-            return testAppId;
+            LOG.info("Successfully registered application master with appId: {}", testAppId);
+          } catch (Throwable ex) {
+            LOG.error("Failed to register application master with appId: {}", testAppId, ex);
+            testAppId = null;
          }
+
+          return testAppId;
        });

-    Assert.assertEquals(
-        "Number of responses received does not match with request",
-        appIds.size(), responses.size());
+    Assert.assertEquals("Number of responses received does not match with request",
+        tempAppIds.size(), responses.size());

    for (Integer testAppId : responses) {
      Assert.assertNotNull(testAppId);
-      finishApplicationMaster(testAppId.intValue(),
-          FinalApplicationStatus.SUCCEEDED);
+      finishApplicationMaster(testAppId, FinalApplicationStatus.SUCCEEDED);
    }
  }

  @Test
-  public void testMultipleAttemptsSameNode()
-      throws YarnException, IOException, Exception {
+  public void testMultipleAttemptsSameNode() throws Exception {

    String user = "hadoop";
    ApplicationId appId = ApplicationId.newInstance(1, 1);
@ -444,7 +426,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {

    applicationAttemptId = ApplicationAttemptId.newInstance(appId, 2);
    getAMRMProxyService().initializePipeline(applicationAttemptId, user,
-        new Token<AMRMTokenIdentifier>(), null, null, false, null);
+        new Token<>(), null, null, false, null);

    RequestInterceptorChainWrapper chain2 =
        getAMRMProxyService().getPipelines().get(appId);
@ -461,13 +443,10 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
    allocateRequest.setResponseId(1);

    List<Container> containers =
-        new ArrayList<Container>(numberOfResourceRequests);
-    List<ResourceRequest> askList =
-        new ArrayList<ResourceRequest>(numberOfResourceRequests);
+        new ArrayList<>(numberOfResourceRequests);
+    List<ResourceRequest> askList = new ArrayList<>(numberOfResourceRequests);
    for (int testAppId = 0; testAppId < numberOfResourceRequests; testAppId++) {
-      askList.add(createResourceRequest(
-          "test-node-" + Integer.toString(testAppId), 6000, 2,
-          testAppId % 5, 1));
+      askList.add(createResourceRequest("test-node-" + testAppId, 6000, 2, testAppId % 5, 1));
    }

    allocateRequest.setAskList(askList);
@ -495,11 +474,9 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {

      containers.addAll(allocateResponse.getAllocatedContainers());

-      LOG.info("Number of allocated containers in this request: "
-          + Integer.toString(allocateResponse.getAllocatedContainers()
-              .size()));
-      LOG.info("Total number of allocated containers: "
-          + Integer.toString(containers.size()));
+      LOG.info("Number of allocated containers in this request: {}.",
+          allocateResponse.getAllocatedContainers().size());
+      LOG.info("Total number of allocated containers: {}.", containers.size());
      Thread.sleep(10);
    }

@ -517,8 +494,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
        Records.newRecord(AllocateRequest.class);
    allocateRequest.setResponseId(1);

-    List<ContainerId> relList =
-        new ArrayList<ContainerId>(containers.size());
+    List<ContainerId> relList = new ArrayList<>(containers.size());
    for (Container container : containers) {
      relList.add(container.getId());
    }
@ -556,23 +532,21 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
          allocateResponse.getCompletedContainersStatuses());
      containersForReleasedContainerIds.addAll(newlyFinished);

-      LOG.info("Number of containers received in this request: "
-          + Integer.toString(allocateResponse.getAllocatedContainers()
-              .size()));
-      LOG.info("Total number of containers received: "
-          + Integer.toString(containersForReleasedContainerIds.size()));
+      LOG.info("Number of containers received in this request: {}.",
+          allocateResponse.getAllocatedContainers().size());
+      LOG.info("Total number of containers received: {}.",
+          containersForReleasedContainerIds.size());
      Thread.sleep(10);
    }

-    Assert.assertEquals(relList.size(),
-        containersForReleasedContainerIds.size());
+    Assert.assertEquals(relList.size(), containersForReleasedContainerIds.size());
  }

  /**
   * Test AMRMProxy restart with recovery.
   */
  @Test
-  public void testRecovery() throws YarnException, Exception {
+  public void testRecovery() throws Exception {

    Configuration conf = createConfiguration();
    // Use the MockRequestInterceptorAcrossRestart instead for the chain
@ -602,7 +576,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
    // At the time of kill, app1 just registerAM, app2 already did one allocate.
    // Both application should be recovered
    createAndStartAMRMProxyService(conf);
-    Assert.assertTrue(getAMRMProxyService().getPipelines().size() == 2);
+    Assert.assertEquals(2, getAMRMProxyService().getPipelines().size());

    allocateResponse = allocate(testAppId1);
    Assert.assertNotNull(allocateResponse);
@ -610,7 +584,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
    FinishApplicationMasterResponse finishResponse =
        finishApplicationMaster(testAppId1, FinalApplicationStatus.SUCCEEDED);
    Assert.assertNotNull(finishResponse);
-    Assert.assertEquals(true, finishResponse.getIsUnregistered());
+    Assert.assertTrue(finishResponse.getIsUnregistered());

    allocateResponse = allocate(testAppId2);
    Assert.assertNotNull(allocateResponse);
@ -619,7 +593,7 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {
        finishApplicationMaster(testAppId2, FinalApplicationStatus.SUCCEEDED);

    Assert.assertNotNull(finishResponse);
-    Assert.assertEquals(true, finishResponse.getIsUnregistered());
+    Assert.assertTrue(finishResponse.getIsUnregistered());

    int testAppId3 = 3;
    try {
@ -664,23 +638,21 @@ public class TestAMRMProxyService extends BaseAMRMProxyTest {

  @Test
  public void testCheckIfAppExistsInStateStore()
-      throws IOException, YarnException {
+      throws IOException {
    ApplicationId appId = ApplicationId.newInstance(0, 0);
    Configuration conf = createConfiguration();
    conf.setBoolean(YarnConfiguration.FEDERATION_ENABLED, true);

    createAndStartAMRMProxyService(conf);

-    Assert.assertEquals(false,
-        getAMRMProxyService().checkIfAppExistsInStateStore(appId));
+    Assert.assertFalse(getAMRMProxyService().checkIfAppExistsInStateStore(appId));

    Configuration distConf = createConfiguration();
    conf.setBoolean(YarnConfiguration.DIST_SCHEDULING_ENABLED, true);

    createAndStartAMRMProxyService(distConf);

-    Assert.assertEquals(true,
-        getAMRMProxyService().checkIfAppExistsInStateStore(appId));
+    Assert.assertTrue(getAMRMProxyService().checkIfAppExistsInStateStore(appId));
  }

  /**
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestFederationInterceptor.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestFederationInterceptor.java
@ -203,7 +203,7 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
    List<Container> containers = new ArrayList<>(numberOfResourceRequests);
    List<ResourceRequest> askList = new ArrayList<>(numberOfResourceRequests);
    for (int id = 0; id < numberOfResourceRequests; id++) {
-      askList.add(createResourceRequest("test-node-" + Integer.toString(id),
+      askList.add(createResourceRequest("test-node-" + id,
          6000, 2, id % 5, 1));
    }

@ -217,7 +217,7 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {

    containers.addAll(allocateResponse.getAllocatedContainers());
    LOG.info("Number of allocated containers in the original request: "
-        + Integer.toString(allocateResponse.getAllocatedContainers().size()));
+        + allocateResponse.getAllocatedContainers().size());

    // Send max 10 heart beats to receive all the containers. If not, we will
    // fail the test
@ -236,10 +236,9 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
      interceptor.drainAllAsyncQueue(false);

      containers.addAll(allocateResponse.getAllocatedContainers());
-      LOG.info("Number of allocated containers in this request: "
-          + Integer.toString(allocateResponse.getAllocatedContainers().size()));
-      LOG.info("Total number of allocated containers: "
-          + Integer.toString(containers.size()));
+      LOG.info("Number of allocated containers in this request: {}.",
+          allocateResponse.getAllocatedContainers().size());
+      LOG.info("Total number of allocated containers: {}.", containers.size());
      Thread.sleep(10);
    }
    Assert.assertEquals(numberOfAllocationExcepted, containers.size());
@ -250,7 +249,7 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
      throws Exception {
    Assert.assertTrue(containers.size() > 0);
    AllocateRequest allocateRequest = Records.newRecord(AllocateRequest.class);
-    List<ContainerId> relList = new ArrayList<ContainerId>(containers.size());
+    List<ContainerId> relList = new ArrayList<>(containers.size());
    for (Container container : containers) {
      relList.add(container.getId());
    }
@ -267,8 +266,7 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
    // The release containers returned by the mock resource managers will be
    // aggregated and returned back to us, and we can check if total request size
    // and returned size are the same
-    List<ContainerId> containersForReleasedContainerIds =
-        new ArrayList<ContainerId>();
+    List<ContainerId> containersForReleasedContainerIds = new ArrayList<>();
    List<ContainerId> newlyFinished = getCompletedContainerIds(
        allocateResponse.getCompletedContainersStatuses());
    containersForReleasedContainerIds.addAll(newlyFinished);
@ -306,7 +304,7 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
  private void checkAMRMToken(Token amrmToken) {
    if (amrmToken != null) {
      // The token should be the one issued by home MockRM
-      Assert.assertTrue(amrmToken.getKind().equals(Integer.toString(0)));
+      Assert.assertEquals(Integer.toString(0), amrmToken.getKind());
    }
  }

@ -314,69 +312,66 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
  public void testMultipleSubClusters() throws Exception {
    UserGroupInformation ugi =
        interceptor.getUGIWithToken(interceptor.getAttemptId());
-    ugi.doAs(new PrivilegedExceptionAction<Object>() {
-      @Override
-      public Object run() throws Exception {
-        // Register the application
-        RegisterApplicationMasterRequest registerReq =
-            Records.newRecord(RegisterApplicationMasterRequest.class);
-        registerReq.setHost(Integer.toString(testAppId));
-        registerReq.setRpcPort(0);
-        registerReq.setTrackingUrl("");
+    ugi.doAs((PrivilegedExceptionAction<Object>) () -> {
+      // Register the application
+      RegisterApplicationMasterRequest registerReq =
+          Records.newRecord(RegisterApplicationMasterRequest.class);
+      registerReq.setHost(Integer.toString(testAppId));
+      registerReq.setRpcPort(0);
+      registerReq.setTrackingUrl("");

-        RegisterApplicationMasterResponse registerResponse =
-            interceptor.registerApplicationMaster(registerReq);
-        Assert.assertNotNull(registerResponse);
-        lastResponseId = 0;
+      RegisterApplicationMasterResponse registerResponse =
+          interceptor.registerApplicationMaster(registerReq);
+      Assert.assertNotNull(registerResponse);
+      lastResponseId = 0;

-        Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());
+      Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());

-        // Allocate the first batch of containers, with sc1 and sc2 active
-        registerSubCluster(SubClusterId.newInstance("SC-1"));
-        registerSubCluster(SubClusterId.newInstance("SC-2"));
+      // Allocate the first batch of containers, with sc1 and sc2 active
+      registerSubCluster(SubClusterId.newInstance("SC-1"));
+      registerSubCluster(SubClusterId.newInstance("SC-2"));

-        int numberOfContainers = 3;
-        List<Container> containers =
-            getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
-        Assert.assertEquals(2, interceptor.getUnmanagedAMPoolSize());
+      int numberOfContainers = 3;
+      List<Container> containers =
+          getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
+      Assert.assertEquals(2, interceptor.getUnmanagedAMPoolSize());

-        // Allocate the second batch of containers, with sc1 and sc3 active
-        deRegisterSubCluster(SubClusterId.newInstance("SC-2"));
-        registerSubCluster(SubClusterId.newInstance("SC-3"));
+      // Allocate the second batch of containers, with sc1 and sc3 active
+      deRegisterSubCluster(SubClusterId.newInstance("SC-2"));
+      registerSubCluster(SubClusterId.newInstance("SC-3"));

-        numberOfContainers = 1;
-        containers.addAll(
-            getContainersAndAssert(numberOfContainers, numberOfContainers * 2));
-        Assert.assertEquals(3, interceptor.getUnmanagedAMPoolSize());
+      numberOfContainers = 1;
+      containers.addAll(
+          getContainersAndAssert(numberOfContainers, numberOfContainers * 2));
+      Assert.assertEquals(3, interceptor.getUnmanagedAMPoolSize());

-        // Allocate the third batch of containers with only in home sub-cluster
-        // active
-        deRegisterSubCluster(SubClusterId.newInstance("SC-1"));
-        deRegisterSubCluster(SubClusterId.newInstance("SC-3"));
-        registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));
+      // Allocate the third batch of containers with only in home sub-cluster
+      // active
+      deRegisterSubCluster(SubClusterId.newInstance("SC-1"));
+      deRegisterSubCluster(SubClusterId.newInstance("SC-3"));
+      registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));

-        numberOfContainers = 2;
-        containers.addAll(
-            getContainersAndAssert(numberOfContainers, numberOfContainers * 1));
-        Assert.assertEquals(3, interceptor.getUnmanagedAMPoolSize());
+      numberOfContainers = 2;
+      containers.addAll(
+          getContainersAndAssert(numberOfContainers, numberOfContainers));
+      Assert.assertEquals(3, interceptor.getUnmanagedAMPoolSize());

-        // Release all containers
-        releaseContainersAndAssert(containers);
+      // Release all containers
+      releaseContainersAndAssert(containers);

-        // Finish the application
-        FinishApplicationMasterRequest finishReq =
-            Records.newRecord(FinishApplicationMasterRequest.class);
-        finishReq.setDiagnostics("");
-        finishReq.setTrackingUrl("");
-        finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);
+      // Finish the application
+      FinishApplicationMasterRequest finishReq =
+          Records.newRecord(FinishApplicationMasterRequest.class);
+      finishReq.setDiagnostics("");
+      finishReq.setTrackingUrl("");
+      finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);

-        FinishApplicationMasterResponse finishResponse =
-            interceptor.finishApplicationMaster(finishReq);
-        Assert.assertNotNull(finishResponse);
-        Assert.assertEquals(true, finishResponse.getIsUnregistered());
+      FinishApplicationMasterResponse finishResponse =
+          interceptor.finishApplicationMaster(finishReq);
+      Assert.assertNotNull(finishResponse);
+      Assert.assertTrue(finishResponse.getIsUnregistered());

-        return null;
-      }
+      return null;
    });
  }

@ -387,55 +382,52 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
  public void testReregister() throws Exception {
    UserGroupInformation ugi =
        interceptor.getUGIWithToken(interceptor.getAttemptId());
-    ugi.doAs(new PrivilegedExceptionAction<Object>() {
-      @Override
-      public Object run() throws Exception {
+    ugi.doAs((PrivilegedExceptionAction<Object>) () -> {

-        // Register the application
-        RegisterApplicationMasterRequest registerReq =
-            Records.newRecord(RegisterApplicationMasterRequest.class);
-        registerReq.setHost(Integer.toString(testAppId));
-        registerReq.setRpcPort(0);
-        registerReq.setTrackingUrl("");
+      // Register the application
+      RegisterApplicationMasterRequest registerReq =
+          Records.newRecord(RegisterApplicationMasterRequest.class);
+      registerReq.setHost(Integer.toString(testAppId));
+      registerReq.setRpcPort(0);
+      registerReq.setTrackingUrl("");

-        RegisterApplicationMasterResponse registerResponse =
-            interceptor.registerApplicationMaster(registerReq);
-        Assert.assertNotNull(registerResponse);
-        lastResponseId = 0;
+      RegisterApplicationMasterResponse registerResponse =
+          interceptor.registerApplicationMaster(registerReq);
+      Assert.assertNotNull(registerResponse);
+      lastResponseId = 0;

-        Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());
+      Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());

-        // Allocate the first batch of containers
-        registerSubCluster(SubClusterId.newInstance("SC-1"));
-        registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));
+      // Allocate the first batch of containers
+      registerSubCluster(SubClusterId.newInstance("SC-1"));
+      registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));

-        interceptor.setShouldReRegisterNext();
+      interceptor.setShouldReRegisterNext();

-        int numberOfContainers = 3;
-        List<Container> containers =
-            getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
-        Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
+      int numberOfContainers = 3;
+      List<Container> containers =
+          getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
+      Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());

-        interceptor.setShouldReRegisterNext();
+      interceptor.setShouldReRegisterNext();

-        // Release all containers
-        releaseContainersAndAssert(containers);
+      // Release all containers
+      releaseContainersAndAssert(containers);

-        interceptor.setShouldReRegisterNext();
+      interceptor.setShouldReRegisterNext();

-        // Finish the application
-        FinishApplicationMasterRequest finishReq =
-            Records.newRecord(FinishApplicationMasterRequest.class);
-        finishReq.setDiagnostics("");
-        finishReq.setTrackingUrl("");
-        finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);
+      // Finish the application
+      FinishApplicationMasterRequest finishReq =
+          Records.newRecord(FinishApplicationMasterRequest.class);
+      finishReq.setDiagnostics("");
+      finishReq.setTrackingUrl("");
+      finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);

-        FinishApplicationMasterResponse finishResponse =
-            interceptor.finishApplicationMaster(finishReq);
-        Assert.assertNotNull(finishResponse);
-        Assert.assertTrue(finishResponse.getIsUnregistered());
-        return null;
-      }
+      FinishApplicationMasterResponse finishResponse =
+          interceptor.finishApplicationMaster(finishReq);
+      Assert.assertNotNull(finishResponse);
+      Assert.assertTrue(finishResponse.getIsUnregistered());
+      return null;
    });
  }

@ -498,7 +490,7 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
      implements Callable<RegisterApplicationMasterResponse> {
    @Override
    public RegisterApplicationMasterResponse call() throws Exception {
-      RegisterApplicationMasterResponse response = null;
+      RegisterApplicationMasterResponse response;
      try {
        // Use port number 1001 to let mock RM block in the register call
        response = interceptor.registerApplicationMaster(
@ -536,110 +528,107 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
      throws Exception {
    UserGroupInformation ugi =
        interceptor.getUGIWithToken(interceptor.getAttemptId());
-    ugi.doAs(new PrivilegedExceptionAction<Object>() {
-      @Override
-      public Object run() throws Exception {
-        interceptor = new TestableFederationInterceptor();
-        interceptor.init(new AMRMProxyApplicationContextImpl(nmContext,
-            getConf(), attemptId, "test-user", null, null, null, registryObj));
-        interceptor.cleanupRegistry();
+    ugi.doAs((PrivilegedExceptionAction<Object>) () -> {
+      interceptor = new TestableFederationInterceptor();
+      interceptor.init(new AMRMProxyApplicationContextImpl(nmContext,
+          getConf(), attemptId, "test-user", null, null, null, registryObj));
+      interceptor.cleanupRegistry();

-        // Register the application
-        RegisterApplicationMasterRequest registerReq =
-            Records.newRecord(RegisterApplicationMasterRequest.class);
-        registerReq.setHost(Integer.toString(testAppId));
-        registerReq.setRpcPort(testAppId);
-        registerReq.setTrackingUrl("");
+      // Register the application
+      RegisterApplicationMasterRequest registerReq =
+          Records.newRecord(RegisterApplicationMasterRequest.class);
+      registerReq.setHost(Integer.toString(testAppId));
+      registerReq.setRpcPort(testAppId);
+      registerReq.setTrackingUrl("");

-        RegisterApplicationMasterResponse registerResponse =
-            interceptor.registerApplicationMaster(registerReq);
-        Assert.assertNotNull(registerResponse);
-        lastResponseId = 0;
+      RegisterApplicationMasterResponse registerResponse =
+          interceptor.registerApplicationMaster(registerReq);
+      Assert.assertNotNull(registerResponse);
+      lastResponseId = 0;

-        Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());
+      Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());

-        // Allocate one batch of containers
-        registerSubCluster(SubClusterId.newInstance("SC-1"));
-        registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));
+      // Allocate one batch of containers
+      registerSubCluster(SubClusterId.newInstance("SC-1"));
+      registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));

-        int numberOfContainers = 3;
-        List<Container> containers =
-            getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
-        Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
+      int numberOfContainers = 3;
+      List<Container> containers =
+          getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
+      Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());

-        // Make sure all async hb threads are done
-        interceptor.drainAllAsyncQueue(true);
+      // Make sure all async hb threads are done
+      interceptor.drainAllAsyncQueue(true);

-        // Prepare for Federation Interceptor restart and recover
-        Map<String, byte[]> recoveredDataMap =
-            recoverDataMapForAppAttempt(nmStateStore, attemptId);
-        String scEntry =
-            FederationInterceptor.NMSS_SECONDARY_SC_PREFIX + "SC-1";
-        if (registryObj == null) {
-          Assert.assertTrue(recoveredDataMap.containsKey(scEntry));
-        } else {
-          // When AMRMPRoxy HA is enabled, NMSS should not have the UAM token,
-          // it should be in Registry
-          Assert.assertFalse(recoveredDataMap.containsKey(scEntry));
-        }
-
-        // Preserve the mock RM instances
-        MockResourceManagerFacade homeRM = interceptor.getHomeRM();
-        ConcurrentHashMap<String, MockResourceManagerFacade> secondaries =
-            interceptor.getSecondaryRMs();
-
-        // Create a new interceptor instance and recover
-        interceptor = new TestableFederationInterceptor(homeRM, secondaries);
-        interceptor.init(new AMRMProxyApplicationContextImpl(nmContext,
-            getConf(), attemptId, "test-user", null, null, null, registryObj));
-        interceptor.recover(recoveredDataMap);
-
-        Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
-        // SC1 should be initialized to be timed out
-        Assert.assertEquals(1, interceptor.getTimedOutSCs(true).size());
-
-        // The first allocate call expects a fail-over exception and re-register
-        try {
-          AllocateRequest allocateRequest =
-              Records.newRecord(AllocateRequest.class);
-          allocateRequest.setResponseId(lastResponseId);
-          AllocateResponse allocateResponse =
-              interceptor.allocate(allocateRequest);
-          lastResponseId = allocateResponse.getResponseId();
-          Assert.fail("Expecting an ApplicationMasterNotRegisteredException  "
-              + " after FederationInterceptor restarts and recovers");
-        } catch (ApplicationMasterNotRegisteredException e) {
-        }
-        interceptor.registerApplicationMaster(registerReq);
-        lastResponseId = 0;
-
-        // Release all containers
-        releaseContainersAndAssert(containers);
-
-        // Finish the application
-        FinishApplicationMasterRequest finishReq =
-            Records.newRecord(FinishApplicationMasterRequest.class);
-        finishReq.setDiagnostics("");
-        finishReq.setTrackingUrl("");
-        finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);
-
-        FinishApplicationMasterResponse finishResponse =
-            interceptor.finishApplicationMaster(finishReq);
-        Assert.assertNotNull(finishResponse);
-        Assert.assertTrue(finishResponse.getIsUnregistered());
-
-        // After the application succeeds, the registry/NMSS entry should be
-        // cleaned up
-        if (registryObj != null) {
-          Assert.assertEquals(0,
-              interceptor.getRegistryClient().getAllApplications().size());
-        } else {
-          recoveredDataMap =
-              recoverDataMapForAppAttempt(nmStateStore, attemptId);
-          Assert.assertFalse(recoveredDataMap.containsKey(scEntry));
-        }
-        return null;
+      // Prepare for Federation Interceptor restart and recover
+      Map<String, byte[]> recoveredDataMap =
+          recoverDataMapForAppAttempt(nmStateStore, attemptId);
+      String scEntry =
+          FederationInterceptor.NMSS_SECONDARY_SC_PREFIX + "SC-1";
+      if (registryObj == null) {
+        Assert.assertTrue(recoveredDataMap.containsKey(scEntry));
+      } else {
+        // When AMRMPRoxy HA is enabled, NMSS should not have the UAM token,
+        // it should be in Registry
+        Assert.assertFalse(recoveredDataMap.containsKey(scEntry));
      }
+
+      // Preserve the mock RM instances
+      MockResourceManagerFacade homeRM = interceptor.getHomeRM();
+      ConcurrentHashMap<String, MockResourceManagerFacade> secondaries =
+          interceptor.getSecondaryRMs();
+
+      // Create a new interceptor instance and recover
+      interceptor = new TestableFederationInterceptor(homeRM, secondaries);
+      interceptor.init(new AMRMProxyApplicationContextImpl(nmContext,
+          getConf(), attemptId, "test-user", null, null, null, registryObj));
+      interceptor.recover(recoveredDataMap);
+
+      Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
+      // SC1 should be initialized to be timed out
+      Assert.assertEquals(1, interceptor.getTimedOutSCs(true).size());
+
+      // The first allocate call expects a fail-over exception and re-register
+      try {
+        AllocateRequest allocateRequest =
+            Records.newRecord(AllocateRequest.class);
+        allocateRequest.setResponseId(lastResponseId);
+        AllocateResponse allocateResponse =
+            interceptor.allocate(allocateRequest);
+        lastResponseId = allocateResponse.getResponseId();
+        Assert.fail("Expecting an ApplicationMasterNotRegisteredException  "
+            + " after FederationInterceptor restarts and recovers");
+      } catch (ApplicationMasterNotRegisteredException e) {
+      }
+      interceptor.registerApplicationMaster(registerReq);
+      lastResponseId = 0;
+
+      // Release all containers
+      releaseContainersAndAssert(containers);
+
+      // Finish the application
+      FinishApplicationMasterRequest finishReq =
+          Records.newRecord(FinishApplicationMasterRequest.class);
+      finishReq.setDiagnostics("");
+      finishReq.setTrackingUrl("");
+      finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);
+
+      FinishApplicationMasterResponse finishResponse =
+          interceptor.finishApplicationMaster(finishReq);
+      Assert.assertNotNull(finishResponse);
+      Assert.assertTrue(finishResponse.getIsUnregistered());
+
+      // After the application succeeds, the registry/NMSS entry should be
+      // cleaned up
+      if (registryObj != null) {
+        Assert.assertEquals(0,
+            interceptor.getRegistryClient().getAllApplications().size());
+      } else {
+        recoveredDataMap =
+            recoverDataMapForAppAttempt(nmStateStore, attemptId);
+        Assert.assertFalse(recoveredDataMap.containsKey(scEntry));
+      }
+      return null;
    });
  }

@ -774,53 +763,48 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
  public void testSubClusterTimeOut() throws Exception {
    UserGroupInformation ugi =
        interceptor.getUGIWithToken(interceptor.getAttemptId());
-    ugi.doAs(new PrivilegedExceptionAction<Object>() {
-      @Override
-      public Object run() throws Exception {
-        // Register the application first time
-        RegisterApplicationMasterRequest registerReq =
-            Records.newRecord(RegisterApplicationMasterRequest.class);
-        registerReq.setHost(Integer.toString(testAppId));
-        registerReq.setRpcPort(0);
-        registerReq.setTrackingUrl("");
-        RegisterApplicationMasterResponse registerResponse =
-            interceptor.registerApplicationMaster(registerReq);
-        Assert.assertNotNull(registerResponse);
-        lastResponseId = 0;
+    ugi.doAs((PrivilegedExceptionAction<Object>) () -> {
+      // Register the application first time
+      RegisterApplicationMasterRequest registerReq =
+          Records.newRecord(RegisterApplicationMasterRequest.class);
+      registerReq.setHost(Integer.toString(testAppId));
+      registerReq.setRpcPort(0);
+      registerReq.setTrackingUrl("");
+      RegisterApplicationMasterResponse registerResponse =
+          interceptor.registerApplicationMaster(registerReq);
+      Assert.assertNotNull(registerResponse);
+      lastResponseId = 0;

-        registerSubCluster(SubClusterId.newInstance("SC-1"));
+      registerSubCluster(SubClusterId.newInstance("SC-1"));

-        getContainersAndAssert(1, 1);
+      getContainersAndAssert(1, 1);

-        AllocateResponse allocateResponse =
-            interceptor.generateBaseAllocationResponse();
-        Assert.assertEquals(2, allocateResponse.getNumClusterNodes());
-        Assert.assertEquals(0, interceptor.getTimedOutSCs(true).size());
+      AllocateResponse allocateResponse = interceptor.generateBaseAllocationResponse();
+      Assert.assertEquals(2, allocateResponse.getNumClusterNodes());
+      Assert.assertEquals(0, interceptor.getTimedOutSCs(true).size());

-        // Let all SC timeout (home and SC-1), without an allocate from AM
-        Thread.sleep(800);
+      // Let all SC timeout (home and SC-1), without an allocate from AM
+      Thread.sleep(800);

-        // Should not be considered timeout, because there's no recent AM
-        // heartbeat
-        allocateResponse = interceptor.generateBaseAllocationResponse();
-        Assert.assertEquals(2, allocateResponse.getNumClusterNodes());
-        Assert.assertEquals(0, interceptor.getTimedOutSCs(true).size());
+      // Should not be considered timeout, because there's no recent AM
+      // heartbeat
+      allocateResponse = interceptor.generateBaseAllocationResponse();
+      Assert.assertEquals(2, allocateResponse.getNumClusterNodes());
+      Assert.assertEquals(0, interceptor.getTimedOutSCs(true).size());

-        // Generate a duplicate heartbeat from AM, so that it won't really
-        // trigger a heartbeat to all SC
-        AllocateRequest allocateRequest =
-            Records.newRecord(AllocateRequest.class);
-        // Set to lastResponseId - 1 so that it will be considered a duplicate
-        // heartbeat and thus not forwarded to all SCs
-        allocateRequest.setResponseId(lastResponseId - 1);
-        interceptor.allocate(allocateRequest);
+      // Generate a duplicate heartbeat from AM, so that it won't really
+      // trigger a heartbeat to all SC
+      AllocateRequest allocateRequest = Records.newRecord(AllocateRequest.class);
+      // Set to lastResponseId - 1 so that it will be considered a duplicate
+      // heartbeat and thus not forwarded to all SCs
+      allocateRequest.setResponseId(lastResponseId - 1);
+      interceptor.allocate(allocateRequest);

-        // Should be considered timeout
-        allocateResponse = interceptor.generateBaseAllocationResponse();
-        Assert.assertEquals(0, allocateResponse.getNumClusterNodes());
-        Assert.assertEquals(2, interceptor.getTimedOutSCs(true).size());
-        return null;
-      }
+      // Should be considered timeout
+      allocateResponse = interceptor.generateBaseAllocationResponse();
+      Assert.assertEquals(0, allocateResponse.getNumClusterNodes());
+      Assert.assertEquals(2, interceptor.getTimedOutSCs(true).size());
+      return null;
    });
  }

@ -834,87 +818,81 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {

    UserGroupInformation ugi =
        interceptor.getUGIWithToken(interceptor.getAttemptId());
-    ugi.doAs(new PrivilegedExceptionAction<Object>() {
-      @Override
-      public Object run() throws Exception {
-        // Register the application
-        RegisterApplicationMasterResponse registerResponse =
-            interceptor.registerApplicationMaster(registerReq);
-        Assert.assertNotNull(registerResponse);
-        lastResponseId = 0;
+    ugi.doAs((PrivilegedExceptionAction<Object>) () -> {
+      // Register the application
+      RegisterApplicationMasterResponse registerResponse =
+          interceptor.registerApplicationMaster(registerReq);
+      Assert.assertNotNull(registerResponse);
+      lastResponseId = 0;

-        Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());
+      Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());

-        // Allocate one batch of containers
-        registerSubCluster(SubClusterId.newInstance("SC-1"));
-        registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));
+      // Allocate one batch of containers
+      registerSubCluster(SubClusterId.newInstance("SC-1"));
+      registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));

-        int numberOfContainers = 3;
-        List<Container> containers =
-            getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
-        for (Container c : containers) {
-          LOG.info("Allocated container " + c.getId());
-        }
-        Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
-
-        // Make sure all async hb threads are done
-        interceptor.drainAllAsyncQueue(true);
-
-        // Preserve the mock RM instances for secondaries
-        ConcurrentHashMap<String, MockResourceManagerFacade> secondaries =
-            interceptor.getSecondaryRMs();
-
-        // Increase the attemptId and create a new interceptor instance for it
-        attemptId = ApplicationAttemptId.newInstance(
-            attemptId.getApplicationId(), attemptId.getAttemptId() + 1);
-
-        interceptor = new TestableFederationInterceptor(null, secondaries);
-        interceptor.init(new AMRMProxyApplicationContextImpl(nmContext,
-            getConf(), attemptId, "test-user", null, null, null, registry));
-        return null;
+      int numberOfContainers = 3;
+      List<Container> containers =
+          getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
+      for (Container c : containers) {
+        LOG.info("Allocated container {}.", c.getId());
      }
+      Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
+
+      // Make sure all async hb threads are done
+      interceptor.drainAllAsyncQueue(true);
+
+      // Preserve the mock RM instances for secondaries
+      ConcurrentHashMap<String, MockResourceManagerFacade> secondaries =
+          interceptor.getSecondaryRMs();
+
+      // Increase the attemptId and create a new interceptor instance for it
+      attemptId = ApplicationAttemptId.newInstance(
+          attemptId.getApplicationId(), attemptId.getAttemptId() + 1);
+
+      interceptor = new TestableFederationInterceptor(null, secondaries);
+      interceptor.init(new AMRMProxyApplicationContextImpl(nmContext,
+          getConf(), attemptId, "test-user", null, null, null, registry));
+      return null;
    });

    // Update the ugi with new attemptId
    ugi = interceptor.getUGIWithToken(interceptor.getAttemptId());
-    ugi.doAs(new PrivilegedExceptionAction<Object>() {
-      @Override
-      public Object run() throws Exception {
-        RegisterApplicationMasterResponse registerResponse =
-            interceptor.registerApplicationMaster(registerReq);
-        lastResponseId = 0;
+    ugi.doAs((PrivilegedExceptionAction<Object>) () -> {
+      RegisterApplicationMasterResponse registerResponse =
+          interceptor.registerApplicationMaster(registerReq);
+      lastResponseId = 0;

-        int numberOfContainers = 3;
-        // Should re-attach secondaries and get the three running containers
-        Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
-        // SC1 should be initialized to be timed out
-        Assert.assertEquals(1, interceptor.getTimedOutSCs(true).size());
-        Assert.assertEquals(numberOfContainers,
-            registerResponse.getContainersFromPreviousAttempts().size());
+      int numberOfContainers = 3;
+      // Should re-attach secondaries and get the three running containers
+      Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
+      // SC1 should be initialized to be timed out
+      Assert.assertEquals(1, interceptor.getTimedOutSCs(true).size());
+      Assert.assertEquals(numberOfContainers,
+          registerResponse.getContainersFromPreviousAttempts().size());

-        // Release all containers
-        releaseContainersAndAssert(
-            registerResponse.getContainersFromPreviousAttempts());
+      // Release all containers
+      releaseContainersAndAssert(
+          registerResponse.getContainersFromPreviousAttempts());

-        // Finish the application
-        FinishApplicationMasterRequest finishReq =
-            Records.newRecord(FinishApplicationMasterRequest.class);
-        finishReq.setDiagnostics("");
-        finishReq.setTrackingUrl("");
-        finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);
+      // Finish the application
+      FinishApplicationMasterRequest finishReq =
+          Records.newRecord(FinishApplicationMasterRequest.class);
+      finishReq.setDiagnostics("");
+      finishReq.setTrackingUrl("");
+      finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);

-        FinishApplicationMasterResponse finishResponse =
-            interceptor.finishApplicationMaster(finishReq);
-        Assert.assertNotNull(finishResponse);
-        Assert.assertTrue(finishResponse.getIsUnregistered());
+      FinishApplicationMasterResponse finishResponse =
+          interceptor.finishApplicationMaster(finishReq);
+      Assert.assertNotNull(finishResponse);
+      Assert.assertTrue(finishResponse.getIsUnregistered());

-        // After the application succeeds, the registry entry should be deleted
-        if (interceptor.getRegistryClient() != null) {
-          Assert.assertEquals(0,
-              interceptor.getRegistryClient().getAllApplications().size());
-        }
-        return null;
+      // After the application succeeds, the registry entry should be deleted
+      if (interceptor.getRegistryClient() != null) {
+        Assert.assertEquals(0,
+            interceptor.getRegistryClient().getAllApplications().size());
      }
+      return null;
    });
  }

@ -924,22 +902,17 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
    ContainerStatus cStatus = Records.newRecord(ContainerStatus.class);
    cStatus.setContainerId(cid);
    Container container =
-            Container.newInstance(cid, null, null, null, null, null);
-
+        Container.newInstance(cid, null, null, null, null, null);

    AllocateResponse homeResponse = Records.newRecord(AllocateResponse.class);
    homeResponse.setAllocatedContainers(Collections.singletonList(container));
-    homeResponse.setCompletedContainersStatuses(
-        Collections.singletonList(cStatus));
-    homeResponse.setUpdatedNodes(
-            Collections.singletonList(Records.newRecord(NodeReport.class)));
-    homeResponse.setNMTokens(
-            Collections.singletonList(Records.newRecord(NMToken.class)));
-    homeResponse.setUpdatedContainers(
-            Collections.singletonList(
-                Records.newRecord(UpdatedContainer.class)));
-    homeResponse.setUpdateErrors(Collections
-            .singletonList(Records.newRecord(UpdateContainerError.class)));
+    homeResponse.setCompletedContainersStatuses(Collections.singletonList(cStatus));
+    homeResponse.setUpdatedNodes(Collections.singletonList(Records.newRecord(NodeReport.class)));
+    homeResponse.setNMTokens(Collections.singletonList(Records.newRecord(NMToken.class)));
+    homeResponse.setUpdatedContainers(Collections.singletonList(
+        Records.newRecord(UpdatedContainer.class)));
+    homeResponse.setUpdateErrors(Collections.singletonList(
+        Records.newRecord(UpdateContainerError.class)));
    homeResponse.setAvailableResources(Records.newRecord(Resource.class));
    homeResponse.setPreemptionMessage(createDummyPreemptionMessage(
        ContainerId.newContainerId(attemptId, 0)));
@ -947,15 +920,12 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
    AllocateResponse response = Records.newRecord(AllocateResponse.class);
    response.setAllocatedContainers(Collections.singletonList(container));
    response.setCompletedContainersStatuses(Collections.singletonList(cStatus));
-    response.setUpdatedNodes(
-            Collections.singletonList(Records.newRecord(NodeReport.class)));
-    response.setNMTokens(
-            Collections.singletonList(Records.newRecord(NMToken.class)));
-    response.setUpdatedContainers(
-            Collections.singletonList(
-                Records.newRecord(UpdatedContainer.class)));
-    response.setUpdateErrors(Collections
-            .singletonList(Records.newRecord(UpdateContainerError.class)));
+    response.setUpdatedNodes(Collections.singletonList(Records.newRecord(NodeReport.class)));
+    response.setNMTokens(Collections.singletonList(Records.newRecord(NMToken.class)));
+    response.setUpdatedContainers(Collections.singletonList(
+        Records.newRecord(UpdatedContainer.class)));
+    response.setUpdateErrors(Collections.singletonList(
+        Records.newRecord(UpdateContainerError.class)));
    response.setAvailableResources(Records.newRecord(Resource.class));
    response.setPreemptionMessage(createDummyPreemptionMessage(
        ContainerId.newContainerId(attemptId, 1)));
@ -964,14 +934,10 @@ public class TestFederationInterceptor extends BaseAMRMProxyTest {
        response, SubClusterId.newInstance("SC-1"));

    Assert.assertEquals(2,
-        homeResponse.getPreemptionMessage().getContract()
-            .getContainers().size());
-    Assert.assertEquals(2,
-        homeResponse.getAllocatedContainers().size());
-    Assert.assertEquals(2,
-        homeResponse.getUpdatedNodes().size());
-    Assert.assertEquals(2,
-        homeResponse.getCompletedContainersStatuses().size());
+        homeResponse.getPreemptionMessage().getContract().getContainers().size());
+    Assert.assertEquals(2, homeResponse.getAllocatedContainers().size());
+    Assert.assertEquals(2, homeResponse.getUpdatedNodes().size());
+    Assert.assertEquals(2, homeResponse.getCompletedContainersStatuses().size());
  }

  private PreemptionMessage createDummyPreemptionMessage(
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestFederationInterceptorSecure.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestFederationInterceptorSecure.java
@ -247,10 +247,10 @@ public class TestFederationInterceptorSecure extends BaseAMRMProxyTest {
  private List<Container> getContainersAndAssert(int numberOfResourceRequests,
      int numberOfAllocationExcepted) throws Exception {
    AllocateRequest allocateRequest = Records.newRecord(AllocateRequest.class);
-    List<Container> containers = new ArrayList<Container>(numberOfResourceRequests);
-    List<ResourceRequest> askList = new ArrayList<ResourceRequest>(numberOfResourceRequests);
+    List<Container> containers = new ArrayList<>(numberOfResourceRequests);
+    List<ResourceRequest> askList = new ArrayList<>(numberOfResourceRequests);
    for (int id = 0; id < numberOfResourceRequests; id++) {
-      askList.add(createResourceRequest("test-node-" + Integer.toString(id), 6000, 2, id % 5, 1));
+      askList.add(createResourceRequest("test-node-" + id, 6000, 2, id % 5, 1));
    }

    allocateRequest.setAskList(askList);
@ -280,9 +280,9 @@ public class TestFederationInterceptorSecure extends BaseAMRMProxyTest {
      interceptor.drainAllAsyncQueue(false);

      containers.addAll(allocateResponse.getAllocatedContainers());
-      LOG.info("Number of allocated containers in this request: "
-          + Integer.toString(allocateResponse.getAllocatedContainers().size()));
-      LOG.info("Total number of allocated containers: {}", containers.size());
+      LOG.info("Number of allocated containers in this request: {}.",
+          allocateResponse.getAllocatedContainers().size());
+      LOG.info("Total number of allocated containers: {}.", containers.size());
      Thread.sleep(10);
    }
    Assert.assertEquals(numberOfAllocationExcepted, containers.size());
@ -293,7 +293,7 @@ public class TestFederationInterceptorSecure extends BaseAMRMProxyTest {
      throws Exception {
    Assert.assertTrue(containers.size() > 0);
    AllocateRequest allocateRequest = Records.newRecord(AllocateRequest.class);
-    List<ContainerId> relList = new ArrayList<ContainerId>(containers.size());
+    List<ContainerId> relList = new ArrayList<>(containers.size());
    for (Container container : containers) {
      relList.add(container.getId());
    }
@ -308,9 +308,9 @@ public class TestFederationInterceptorSecure extends BaseAMRMProxyTest {

    // The release request will be split and handled by the corresponding UAM.
    // The release containers returned by the mock resource managers will be
-    // aggregated and returned back to us and we can check if total request size
+    // aggregated and returned back to us, and we can check if total request size
    // and returned size are the same
-    List<ContainerId> containersForReleasedContainerIds = new ArrayList<ContainerId>();
+    List<ContainerId> containersForReleasedContainerIds = new ArrayList<>();
    List<ContainerId> newlyFinished = getCompletedContainerIds(
        allocateResponse.getCompletedContainersStatuses());
    containersForReleasedContainerIds.addAll(newlyFinished);
@ -331,8 +331,9 @@ public class TestFederationInterceptorSecure extends BaseAMRMProxyTest {

      newlyFinished = getCompletedContainerIds(allocateResponse.getCompletedContainersStatuses());
      containersForReleasedContainerIds.addAll(newlyFinished);
-      LOG.info("Number of containers received in this request: ", newlyFinished.size());
-      LOG.info("Total number of containers received: ", containersForReleasedContainerIds.size());
+      LOG.info("Number of containers received in this request: {}.", newlyFinished.size());
+      LOG.info("Total number of containers received: {}.",
+          containersForReleasedContainerIds.size());
      Thread.sleep(10);
    }

@ -342,7 +343,7 @@ public class TestFederationInterceptorSecure extends BaseAMRMProxyTest {
  private void checkAMRMToken(Token amrmToken) {
    if (amrmToken != null) {
      // The token should be the one issued by home MockRM
-      Assert.assertTrue(amrmToken.getKind().equals(Integer.toString(0)));
+      Assert.assertEquals(Integer.toString(0), amrmToken.getKind());
    }
  }

@ -360,106 +361,103 @@ public class TestFederationInterceptorSecure extends BaseAMRMProxyTest {
      final RegistryOperations registryObj)
      throws Exception {
    UserGroupInformation ugi = this.getUGIWithToken(attemptId);
-    ugi.doAs(new PrivilegedExceptionAction<Object>() {
-      @Override
-      public Object run() throws Exception {
-        interceptor = new TestableFederationInterceptor(mockHomeRm);
-        interceptor.init(new AMRMProxyApplicationContextImpl(nmContext, conf, attemptId,
-            "test-user", null, null, null, registryObj));
-        interceptor.cleanupRegistry();
+    ugi.doAs((PrivilegedExceptionAction<Object>) () -> {
+      interceptor = new TestableFederationInterceptor(mockHomeRm);
+      interceptor.init(new AMRMProxyApplicationContextImpl(nmContext, conf, attemptId,
+          "test-user", null, null, null, registryObj));
+      interceptor.cleanupRegistry();

-        // Register the application
-        RegisterApplicationMasterRequest registerReq =
-            Records.newRecord(RegisterApplicationMasterRequest.class);
-        registerReq.setHost(Integer.toString(testAppId));
-        registerReq.setRpcPort(testAppId);
-        registerReq.setTrackingUrl("");
+      // Register the application
+      RegisterApplicationMasterRequest registerReq =
+          Records.newRecord(RegisterApplicationMasterRequest.class);
+      registerReq.setHost(Integer.toString(testAppId));
+      registerReq.setRpcPort(testAppId);
+      registerReq.setTrackingUrl("");

-        RegisterApplicationMasterResponse registerResponse =
-            interceptor.registerApplicationMaster(registerReq);
-        Assert.assertNotNull(registerResponse);
-        lastResponseId = 0;
+      RegisterApplicationMasterResponse registerResponse =
+          interceptor.registerApplicationMaster(registerReq);
+      Assert.assertNotNull(registerResponse);
+      lastResponseId = 0;

-        Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());
+      Assert.assertEquals(0, interceptor.getUnmanagedAMPoolSize());

-        // Allocate one batch of containers
-        registerSubCluster(SubClusterId.newInstance(SC_ID1));
-        registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));
+      // Allocate one batch of containers
+      registerSubCluster(SubClusterId.newInstance(SC_ID1));
+      registerSubCluster(SubClusterId.newInstance(HOME_SC_ID));

-        int numberOfContainers = 3;
-        List<Container> containers =
-            getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
-        Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
+      int numberOfContainers = 3;
+      List<Container> containers =
+          getContainersAndAssert(numberOfContainers, numberOfContainers * 2);
+      Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());

-        // Make sure all async hb threads are done
-        interceptor.drainAllAsyncQueue(true);
+      // Make sure all async hb threads are done
+      interceptor.drainAllAsyncQueue(true);

-        // Prepare for Federation Interceptor restart and recover
-        Map<String, byte[]> recoveredDataMap = recoverDataMapForAppAttempt(nmStateStore, attemptId);
-        String scEntry = FederationInterceptor.NMSS_SECONDARY_SC_PREFIX + "SC-1";
-        if (registryObj == null) {
-          Assert.assertTrue(recoveredDataMap.containsKey(scEntry));
-        } else {
-          // When AMRMPRoxy HA is enabled, NMSS should not have the UAM token,
-          // it should be in Registry
-          Assert.assertFalse(recoveredDataMap.containsKey(scEntry));
-        }
-
-        // Preserve the mock RM instances
-        MockResourceManagerFacade homeRM = interceptor.getHomeRM();
-        ConcurrentHashMap<String, MockResourceManagerFacade> secondaries =
-            interceptor.getSecondaryRMs();
-
-        // Create a new interceptor instance and recover
-        interceptor = new TestableFederationInterceptor(homeRM, secondaries);
-        interceptor.init(new AMRMProxyApplicationContextImpl(nmContext, conf, attemptId,
-            "test-user", null, null, null, registryObj));
-        interceptor.setClientRPC(true);
-        interceptor.recover(recoveredDataMap);
-        interceptor.setClientRPC(false);
-
-        Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
-        // SC-1 should be initialized to be timed out
-        Assert.assertEquals(1, interceptor.getTimedOutSCs(true).size());
-
-        // The first allocate call expects a fail-over exception and re-register
-        try {
-          AllocateRequest allocateRequest = Records.newRecord(AllocateRequest.class);
-          allocateRequest.setResponseId(lastResponseId);
-          AllocateResponse allocateResponse = interceptor.allocate(allocateRequest);
-          lastResponseId = allocateResponse.getResponseId();
-          Assert.fail("Expecting an ApplicationMasterNotRegisteredException  "
-              + " after FederationInterceptor restarts and recovers");
-        } catch (ApplicationMasterNotRegisteredException e) {
-        }
-        interceptor.registerApplicationMaster(registerReq);
-        lastResponseId = 0;
-
-        // Release all containers
-        releaseContainersAndAssert(containers);
-
-        // Finish the application
-        FinishApplicationMasterRequest finishReq =
-            Records.newRecord(FinishApplicationMasterRequest.class);
-        finishReq.setDiagnostics("");
-        finishReq.setTrackingUrl("");
-        finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);
-
-        FinishApplicationMasterResponse finishResponse =
-            interceptor.finishApplicationMaster(finishReq);
-        Assert.assertNotNull(finishResponse);
-        Assert.assertEquals(true, finishResponse.getIsUnregistered());
-
-        // After the application succeeds, the registry/NMSS entry should be
-        // cleaned up
-        if (registryObj != null) {
-          Assert.assertEquals(0, interceptor.getRegistryClient().getAllApplications().size());
-        } else {
-          recoveredDataMap = recoverDataMapForAppAttempt(nmStateStore, attemptId);
-          Assert.assertFalse(recoveredDataMap.containsKey(scEntry));
-        }
-        return null;
+      // Prepare for Federation Interceptor restart and recover
+      Map<String, byte[]> recoveredDataMap = recoverDataMapForAppAttempt(nmStateStore, attemptId);
+      String scEntry = FederationInterceptor.NMSS_SECONDARY_SC_PREFIX + "SC-1";
+      if (registryObj == null) {
+        Assert.assertTrue(recoveredDataMap.containsKey(scEntry));
+      } else {
+        // When AMRMPRoxy HA is enabled, NMSS should not have the UAM token,
+        // it should be in Registry
+        Assert.assertFalse(recoveredDataMap.containsKey(scEntry));
      }
+
+      // Preserve the mock RM instances
+      MockResourceManagerFacade homeRM = interceptor.getHomeRM();
+      ConcurrentHashMap<String, MockResourceManagerFacade> secondaries =
+          interceptor.getSecondaryRMs();
+
+      // Create a new interceptor instance and recover
+      interceptor = new TestableFederationInterceptor(homeRM, secondaries);
+      interceptor.init(new AMRMProxyApplicationContextImpl(nmContext, conf, attemptId,
+          "test-user", null, null, null, registryObj));
+      interceptor.setClientRPC(true);
+      interceptor.recover(recoveredDataMap);
+      interceptor.setClientRPC(false);
+
+      Assert.assertEquals(1, interceptor.getUnmanagedAMPoolSize());
+      // SC-1 should be initialized to be timed out
+      Assert.assertEquals(1, interceptor.getTimedOutSCs(true).size());
+
+      // The first allocate call expects a fail-over exception and re-register
+      try {
+        AllocateRequest allocateRequest = Records.newRecord(AllocateRequest.class);
+        allocateRequest.setResponseId(lastResponseId);
+        AllocateResponse allocateResponse = interceptor.allocate(allocateRequest);
+        lastResponseId = allocateResponse.getResponseId();
+        Assert.fail("Expecting an ApplicationMasterNotRegisteredException  "
+            + " after FederationInterceptor restarts and recovers");
+      } catch (ApplicationMasterNotRegisteredException e) {
+      }
+      interceptor.registerApplicationMaster(registerReq);
+      lastResponseId = 0;
+
+      // Release all containers
+      releaseContainersAndAssert(containers);
+
+      // Finish the application
+      FinishApplicationMasterRequest finishReq =
+          Records.newRecord(FinishApplicationMasterRequest.class);
+      finishReq.setDiagnostics("");
+      finishReq.setTrackingUrl("");
+      finishReq.setFinalApplicationStatus(FinalApplicationStatus.SUCCEEDED);
+
+      FinishApplicationMasterResponse finishResponse =
+          interceptor.finishApplicationMaster(finishReq);
+      Assert.assertNotNull(finishResponse);
+      Assert.assertTrue(finishResponse.getIsUnregistered());
+
+      // After the application succeeds, the registry/NMSS entry should be
+      // cleaned up
+      if (registryObj != null) {
+        Assert.assertEquals(0, interceptor.getRegistryClient().getAllApplications().size());
+      } else {
+        recoveredDataMap = recoverDataMapForAppAttempt(nmStateStore, attemptId);
+        Assert.assertFalse(recoveredDataMap.containsKey(scEntry));
+      }
+      return null;
    });
  }

--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestableFederationInterceptor.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/TestableFederationInterceptor.java
@ -77,7 +77,7 @@ public class TestableFederationInterceptor extends FederationInterceptor {
  }

  @Override
-  protected AMHeartbeatRequestHandler createHomeHeartbeartHandler(
+  protected AMHeartbeatRequestHandler createHomeHeartbeatHandler(
      Configuration conf, ApplicationId appId,
      AMRMClientRelayer rmProxyRelayer) {
    return new TestableAMRequestHandlerThread(conf, appId, rmProxyRelayer);
@ -142,7 +142,7 @@ public class TestableFederationInterceptor extends FederationInterceptor {
  }

  /**
-   * Drain all aysnc heartbeat threads, comes in two favors:
+   * Drain all async heartbeat threads, comes in two favors:
   *
   * 1. waitForAsyncHBThreadFinish == false. Only wait for the async threads to
   * pick up all pending heartbeat requests. Not necessarily wait for all
@ -159,9 +159,9 @@ public class TestableFederationInterceptor extends FederationInterceptor {

    LOG.info("waiting to drain home heartbeat handler");
    if (waitForAsyncHBThreadFinish) {
-      getHomeHeartbeartHandler().drainHeartbeatThread();
+      getHomeHeartbeatHandler().drainHeartbeatThread();
    } else {
-      while (getHomeHeartbeartHandler().getRequestQueueSize() > 0) {
+      while (getHomeHeartbeatHandler().getRequestQueueSize() > 0) {
        try {
          Thread.sleep(10);
        } catch (InterruptedException e) {
@ -291,12 +291,9 @@ public class TestableFederationInterceptor extends FederationInterceptor {
    public void run() {
      try {
        getUGIWithToken(getAttemptId())
-            .doAs(new PrivilegedExceptionAction<Object>() {
-              @Override
-              public Object run() {
-                TestableAMRequestHandlerThread.super.run();
-                return null;
-              }
+            .doAs((PrivilegedExceptionAction<Object>) () -> {
+              TestableAMRequestHandlerThread.super.run();
+              return null;
            });
      } catch (Exception e) {
      }