diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/rm/TestRMContainerAllocator.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/rm/TestRMContainerAllocator.java
index 6c74a7a..e4a8a1a 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/rm/TestRMContainerAllocator.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/rm/TestRMContainerAllocator.java
@@ -142,7 +142,6 @@
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.event.SchedulerEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fifo.FifoScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.security.AMRMTokenSecretManager;
-import org.apache.hadoop.yarn.server.timelineservice.security.TimelineV2DelegationTokenSecretManagerService.TimelineV2DelegationTokenSecretManager;
 import org.apache.hadoop.yarn.server.utils.BuilderUtils;
 import org.apache.hadoop.yarn.util.Clock;
 import org.apache.hadoop.yarn.util.ControlledClock;
@@ -777,7 +776,7 @@
         new Text("renewer"), null);
     ident.setSequenceNumber(1);
     Token<TimelineDelegationTokenIdentifier> collectorToken =
-        new Token<TimelineDelegationTokenIdentifier> (ident.getBytes(),
+        new Token<TimelineDelegationTokenIdentifier>(ident.getBytes(),
         new byte[0], TimelineDelegationTokenIdentifier.KIND_NAME,
         new Text(localAddr));
     org.apache.hadoop.yarn.api.records.Token token =
@@ -825,7 +824,7 @@
     // new token.
     ident.setSequenceNumber(100);
     Token<TimelineDelegationTokenIdentifier> collectorToken1 =
-        new Token<TimelineDelegationTokenIdentifier> (ident.getBytes(),
+        new Token<TimelineDelegationTokenIdentifier>(ident.getBytes(),
         new byte[0], TimelineDelegationTokenIdentifier.KIND_NAME,
         new Text(localAddr));
     token = org.apache.hadoop.yarn.api.records.Token.newInstance(
@@ -3585,15 +3584,15 @@
     }
   }
 
-  private static class MockSchedulerForTimelineCollector
+  private final static class MockSchedulerForTimelineCollector
       implements ApplicationMasterProtocol {
-    CollectorInfo collectorInfo;
+    private CollectorInfo collectorInfo;
 
-    public MockSchedulerForTimelineCollector(CollectorInfo info) {
+    private MockSchedulerForTimelineCollector(CollectorInfo info) {
       this.collectorInfo = info;
     }
 
-    void updateCollectorInfo(CollectorInfo info) {
+    private void updateCollectorInfo(CollectorInfo info) {
       collectorInfo = info;
     }
 
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/jobhistory/TaskAttemptUnsuccessfulCompletionEvent.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/jobhistory/TaskAttemptUnsuccessfulCompletionEvent.java
index 1529125..9afa093 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/jobhistory/TaskAttemptUnsuccessfulCompletionEvent.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/jobhistory/TaskAttemptUnsuccessfulCompletionEvent.java
@@ -62,7 +62,7 @@
   private long startTime;
   private static final Counters EMPTY_COUNTERS = new Counters();
 
-  /** 
+  /**
    * Create an event to record the unsuccessful completion of attempts.
    * @param id Attempt ID
    * @param taskType Type of the task
@@ -227,12 +227,12 @@
   public String getHostname() { return hostname; }
   /** Gets the rpc port for the host where the attempt executed. */
   public int getPort() { return port; }
-  
+
   /** Gets the rack name of the node where the attempt ran. */
   public String getRackName() {
     return rackName == null ? null : rackName.toString();
   }
-  
+
   /** Gets the error string. */
   public String getError() { return error.toString(); }
   /**
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/TestMRTimelineEventHandling.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/TestMRTimelineEventHandling.java
index 9434d46..19313d3 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/TestMRTimelineEventHandling.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/TestMRTimelineEventHandling.java
@@ -398,7 +398,7 @@
 
           LOG.info("strLine.trim()= " + strLine.trim());
           if (checkIdPrefix) {
-            Assert.assertTrue("Entity ID prefix expected to be > 0" ,
+            Assert.assertTrue("Entity ID prefix expected to be > 0",
                 entity.getIdPrefix() > 0);
             if (idPrefix == -1) {
               idPrefix = entity.getIdPrefix();
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java
index a330242..2c1b1ec 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java
@@ -2116,7 +2116,7 @@
       TIMELINE_SERVICE_PREFIX + "reader.class";
 
   public static final String DEFAULT_TIMELINE_SERVICE_READER_CLASS =
-      "org.apache.hadoop.yarn.server.timelineservice.storage" + 
+      "org.apache.hadoop.yarn.server.timelineservice.storage" +
           ".HBaseTimelineReaderImpl";
 
   /**
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDistributedShell.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDistributedShell.java
index 47485ae..fc270cb 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDistributedShell.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDistributedShell.java
@@ -652,7 +652,7 @@
           if (checkIdPrefix) {
             TimelineEntity entity = FileSystemTimelineReaderImpl.
                 getTimelineRecordFromJSON(entityLine, TimelineEntity.class);
-            Assert.assertTrue("Entity ID prefix expected to be > 0" ,
+            Assert.assertTrue("Entity ID prefix expected to be > 0",
                 entity.getIdPrefix() > 0);
             if (idPrefix == -1) {
               idPrefix = entity.getIdPrefix();
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/client/api/TimelineV2Client.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/client/api/TimelineV2Client.java
index da81a91..423c059 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/client/api/TimelineV2Client.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/client/api/TimelineV2Client.java
@@ -24,7 +24,6 @@
 import org.apache.hadoop.service.CompositeService;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.CollectorInfo;
-import org.apache.hadoop.yarn.api.records.Token;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
 import org.apache.hadoop.yarn.client.api.impl.TimelineV2ClientImpl;
 import org.apache.hadoop.yarn.exceptions.YarnException;
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml
index ae022e4..17d0496 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml
@@ -3188,7 +3188,7 @@
     <name>yarn.timeline-service.http-cross-origin.enabled</name>
     <value>false</value>
   </property>
-  
+ 
   <property>
     <description>
       Flag to enable cross-origin (CORS) support for timeline service v1.x or
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/timeline/security/TimelineAuthenticationFilterInitializer.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/timeline/security/TimelineAuthenticationFilterInitializer.java
index 06f9868e..3d8ce05 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/timeline/security/TimelineAuthenticationFilterInitializer.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/timeline/security/TimelineAuthenticationFilterInitializer.java
@@ -53,7 +53,8 @@
   /**
    * The configuration prefix of timeline HTTP authentication.
    */
-  public static final String PREFIX = "yarn.timeline-service.http-authentication.";
+  public static final String PREFIX =
+      "yarn.timeline-service.http-authentication.";
 
   @VisibleForTesting
   Map<String, String> filterConfig;
@@ -104,15 +105,15 @@
   }
 
   /**
-   * Initializes {@link TimelineAuthenticationFilter}
+   * Initializes {@link TimelineAuthenticationFilter}.
    * <p>
    * Propagates to {@link TimelineAuthenticationFilter} configuration all YARN
-   * configuration properties prefixed with {@value #PREFIX}
+   * configuration properties prefixed with {@value #PREFIX}.
    *
    * @param container
-   *          The filter container
+   *          The filter container.
    * @param conf
-   *          Configuration for run-time parameters
+   *          Configuration for run-time parameters.
    */
   @Override
   public void initFilter(FilterContainer container, Configuration conf) {
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/test/java/org/apache/hadoop/yarn/server/timeline/security/TestTimelineAuthenticationFilterInitializer.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/test/java/org/apache/hadoop/yarn/server/timeline/security/TestTimelineAuthenticationFilterInitializer.java
index 430911e..44f63ea 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/test/java/org/apache/hadoop/yarn/server/timeline/security/TestTimelineAuthenticationFilterInitializer.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/test/java/org/apache/hadoop/yarn/server/timeline/security/TestTimelineAuthenticationFilterInitializer.java
@@ -27,7 +27,9 @@
 import org.junit.Test;
 import org.mockito.Mockito;
 
-
+/**
+ * Tests {@link TimelineAuthenticationFilterInitializer}.
+ */
 public class TestTimelineAuthenticationFilterInitializer {
 
   @Test
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/security/authorize/NMPolicyProvider.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/security/authorize/NMPolicyProvider.java
index cc668f7..7b28659 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/security/authorize/NMPolicyProvider.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/security/authorize/NMPolicyProvider.java
@@ -33,21 +33,21 @@
 @InterfaceStability.Unstable
 public class NMPolicyProvider extends PolicyProvider {
   
-  private static final Service[] nodeManagerServices = 
+  private static final Service[] NODE_MANAGER_SERVICES =
       new Service[] {
-    new Service(
-        YarnConfiguration.YARN_SECURITY_SERVICE_AUTHORIZATION_CONTAINER_MANAGEMENT_PROTOCOL, 
-        ContainerManagementProtocolPB.class),
-    new Service(YarnConfiguration.YARN_SECURITY_SERVICE_AUTHORIZATION_RESOURCE_LOCALIZER, 
-        LocalizationProtocolPB.class),
-    new Service(YarnConfiguration.
-        YARN_SECURITY_SERVICE_AUTHORIZATION_COLLECTOR_NODEMANAGER_PROTOCOL,
+          new Service(YarnConfiguration.
+            YARN_SECURITY_SERVICE_AUTHORIZATION_CONTAINER_MANAGEMENT_PROTOCOL,
+            ContainerManagementProtocolPB.class),
+          new Service(YarnConfiguration.
+            YARN_SECURITY_SERVICE_AUTHORIZATION_RESOURCE_LOCALIZER,
+            LocalizationProtocolPB.class),
+          new Service(YarnConfiguration.
+            YARN_SECURITY_SERVICE_AUTHORIZATION_COLLECTOR_NODEMANAGER_PROTOCOL,
             CollectorNodemanagerProtocolPB.class)
-  };
+      };
 
   @Override
   public Service[] getServices() {
-    return nodeManagerServices;
+    return NODE_MANAGER_SERVICES;
   }
-
 }
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/apptoflow/AppToFlowColumnPrefix.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/apptoflow/AppToFlowColumnPrefix.java
index f1e4495..752a380 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/apptoflow/AppToFlowColumnPrefix.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/apptoflow/AppToFlowColumnPrefix.java
@@ -58,7 +58,7 @@
   private final String columnPrefix;
   private final byte[] columnPrefixBytes;
 
-  private AppToFlowColumnPrefix(ColumnFamily<AppToFlowTable> columnFamily,
+  AppToFlowColumnPrefix(ColumnFamily<AppToFlowTable> columnFamily,
       String columnPrefix) {
     this.columnFamily = columnFamily;
     this.columnPrefix = columnPrefix;
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/reader/EntityTypeReader.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/reader/EntityTypeReader.java
index fd85878..05570f1 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/reader/EntityTypeReader.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/reader/EntityTypeReader.java
@@ -91,9 +91,8 @@
 
     int counter = 0;
     while (true) {
-      try (ResultScanner results
-          = getResult(hbaseConf, conn, typeFilterList, currRowKey, nextRowKey))
-      {
+      try (ResultScanner results =
+          getResult(hbaseConf, conn, typeFilterList, currRowKey, nextRowKey)) {
         TimelineEntity entity = parseEntityForType(results.next());
         if (entity == null) {
           break;
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.java
index 1e77155..16d623a 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.java
@@ -125,7 +125,7 @@
    *    <li><b>flowRunId</b> - Context flow run id.</li>
    *    <li><b>appId</b> - Context app id.</li>
    *    </ul>
-   *    Although entityIdPrefix and entityId are also part of context, 
+   *    Although entityIdPrefix and entityId are also part of context,
    *    it has no meaning for getEntities.<br>
    *    Fields in context which are mandatory depends on entity type. Entity
    *    type is always mandatory. In addition to entity type, below is the list
@@ -161,7 +161,7 @@
    *    {@link TimelineDataToRetrieve} for details.
    * @return A set of <cite>TimelineEntity</cite> instances of the given entity
    *    type in the given context scope which matches the given predicates
-   *    ordered by enitityIdPrefix(for generic entities only). 
+   *    ordered by enitityIdPrefix(for generic entities only).
    *    Each entity will only contain
    *    the metadata(id, type , idPrefix and created time) plus the given
    *    fields to retrieve.