YARN-9013. Fix CheckStyle.

Author: slfan1989

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java

@@ -4267,7 +4267,7 @@ public static boolean isAclEnabled(Configuration conf) {
    */
   public static final String ROUTER_CLIENTRM_SUBMIT_RETRY =
       ROUTER_PREFIX + "submit.retry";
-  public static final int DEFAULT_ROUTER_CLIENTRM_SUBMIT_RETRY = 1;
+  public static final int DEFAULT_ROUTER_CLIENTRM_SUBMIT_RETRY = 3;
 
   /**
    * GetNewApplication and SubmitApplication request retry interval time.
@@ -4367,7 +4367,7 @@ public static boolean isAclEnabled(Configuration conf) {
    * the default value is 0s.
    */
   public static final long DEFAULT_ROUTER_USER_CLIENT_THREAD_POOL_KEEP_ALIVE_TIME =
-      TimeUnit.SECONDS.toMillis(30); // 0s
+      TimeUnit.SECONDS.toMillis(0); // 0s
 
   /** The address of the Router web application. */
   public static final String ROUTER_WEBAPP_ADDRESS =

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-globalpolicygenerator/src/test/java/org/apache/hadoop/yarn/server/globalpolicygenerator/applicationcleaner/TestDefaultApplicationCleaner.java

@@ -192,8 +192,11 @@ public void testConcurrentNewApp() throws YarnException {
          GetApplicationsHomeSubClusterRequest.newInstance();
     GetApplicationsHomeSubClusterResponse applicationsHomeSubCluster =
         stateStore.getApplicationsHomeSubCluster(appHomeSubClusterRequest);
-    int size = applicationsHomeSubCluster.getAppsHomeSubClusters().size();
-    Assert.assertEquals(1, size);
+    Assert.assertNotNull(applicationsHomeSubCluster);
+    List<ApplicationHomeSubCluster> appsHomeSubClusters =
+        applicationsHomeSubCluster.getAppsHomeSubClusters();
+    Assert.assertNotNull(appsHomeSubClusters);
+    Assert.assertEquals(1, appsHomeSubClusters.size());
 
     // The concurrently added app should be still there
     Assert.assertEquals(1, registryClient.getAllApplications().size());