diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/ContainerExecutor.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/ContainerExecutor.java
index 8e33535032..9b604cede5 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/ContainerExecutor.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/ContainerExecutor.java
@@ -24,6 +24,7 @@ import java.io.OutputStream;
 import java.io.PrintStream;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -309,7 +310,8 @@ public abstract class ContainerExecutor implements Configurable {
     }
 
     try {
-      return Integer.parseInt(FileUtils.readFileToString(file).trim());
+      return Integer.parseInt(
+          FileUtils.readFileToString(file, Charset.defaultCharset()).trim());
     } catch (NumberFormatException e) {
       throw new IOException("Error parsing exit code from pid " + pid, e);
     }
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerLaunch.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerLaunch.java
index 57abfc3d0f..bb842af0f9 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerLaunch.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerLaunch.java
@@ -22,8 +22,6 @@ import static org.apache.hadoop.fs.CreateFlag.CREATE;
 import static org.apache.hadoop.fs.CreateFlag.OVERWRITE;
 
 import org.apache.hadoop.yarn.server.nodemanager.executor.DeletionAsUserContext;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import java.io.DataOutputStream;
 import java.io.File;
@@ -189,7 +187,6 @@ public class ContainerLaunch implements Callable<Integer> {
   }
 
   @Override
-  @SuppressWarnings("unchecked") // dispatcher not typed
   public Integer call() {
     if (!validateContainerState()) {
       return 0;
@@ -374,7 +371,6 @@ public class ContainerLaunch implements Callable<Integer> {
         .build());
   }
 
-  @SuppressWarnings("unchecked")
   protected boolean validateContainerState() {
     // CONTAINER_KILLED_ON_REQUEST should not be missed if the container
     // is already at KILLING
@@ -486,7 +482,6 @@ public class ContainerLaunch implements Callable<Integer> {
     return localResources;
   }
 
-  @SuppressWarnings("unchecked")
   protected int launchContainer(ContainerStartContext ctx)
       throws IOException, ConfigurationException {
     int launchPrep = prepareForLaunch(ctx);
@@ -496,7 +491,6 @@ public class ContainerLaunch implements Callable<Integer> {
     return launchPrep;
   }
 
-  @SuppressWarnings("unchecked")
   protected int relaunchContainer(ContainerStartContext ctx)
       throws IOException, ConfigurationException {
     int launchPrep = prepareForLaunch(ctx);
@@ -546,7 +540,6 @@ public class ContainerLaunch implements Callable<Integer> {
     }
   }
 
-  @SuppressWarnings("unchecked")
   protected void handleContainerExitCode(int exitCode, Path containerLogDir) {
     ContainerId containerId = container.getContainerId();
 
@@ -592,7 +585,6 @@ public class ContainerLaunch implements Callable<Integer> {
    * @param containerLogDir
    * @param diagnosticInfo
    */
-  @SuppressWarnings("unchecked")
   protected void handleContainerExitWithFailure(ContainerId containerID,
       int ret, Path containerLogDir, StringBuilder diagnosticInfo) {
     LOG.warn("Container launch failed : " + diagnosticInfo.toString());
@@ -727,7 +719,6 @@ public class ContainerLaunch implements Callable<Integer> {
    * the process id is available.
    * @throws IOException
    */
-  @SuppressWarnings("unchecked") // dispatcher not typed
   public void cleanupContainer() throws IOException {
     ContainerId containerId = container.getContainerId();
     String containerIdStr = containerId.toString();
@@ -855,7 +846,6 @@ public class ContainerLaunch implements Callable<Integer> {
    *
    * @throws IOException
    */
-  @SuppressWarnings("unchecked") // dispatcher not typed
   public void signalContainer(SignalContainerCommand command)
       throws IOException {
     ContainerId containerId =
@@ -994,7 +984,6 @@ public class ContainerLaunch implements Callable<Integer> {
    * executor to pause the container.
    * @throws IOException in case of errors.
    */
-  @SuppressWarnings("unchecked") // dispatcher not typed
   public void pauseContainer() throws IOException {
     ContainerId containerId = container.getContainerId();
     String containerIdStr = containerId.toString();
@@ -1044,7 +1033,6 @@ public class ContainerLaunch implements Callable<Integer> {
    * executor to pause the container.
    * @throws IOException in case of error.
    */
-  @SuppressWarnings("unchecked") // dispatcher not typed
   public void resumeContainer() throws IOException {
     ContainerId containerId = container.getContainerId();
     String containerIdStr = containerId.toString();
@@ -1357,6 +1345,7 @@ public class ContainerLaunch implements Callable<Integer> {
   }
 
   private static final class UnixShellScriptBuilder extends ShellScriptBuilder {
+    @SuppressWarnings("unused")
     private void errorCheck() {
       line("hadoop_shell_errorcode=$?");
       line("if [[ \"$hadoop_shell_errorcode\" -ne 0 ]]");
@@ -1651,20 +1640,6 @@ public class ContainerLaunch implements Callable<Integer> {
     }
   }
 
-  private static void putEnvIfNotNull(
-      Map<String, String> environment, String variable, String value) {
-    if (value != null) {
-      environment.put(variable, value);
-    }
-  }
-  
-  private static void putEnvIfAbsent(
-      Map<String, String> environment, String variable) {
-    if (environment.get(variable) == null) {
-      putEnvIfNotNull(environment, variable, System.getenv(variable));
-    }
-  }
-
   private static void addToEnvMap(
       Map<String, String> envMap, Set<String> envSet,
       String envName, String envValue) {
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerRelaunch.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerRelaunch.java
index f69cf967ae..a34ed62505 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerRelaunch.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerRelaunch.java
@@ -58,7 +58,6 @@ public class ContainerRelaunch extends ContainerLaunch {
   }
 
   @Override
-  @SuppressWarnings("unchecked")
   public Integer call() {
     if (!validateContainerState()) {
       return 0;
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/TestContainerLaunch.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/TestContainerLaunch.java
index ebdceead35..ddf46a63ac 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/TestContainerLaunch.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/TestContainerLaunch.java
@@ -776,8 +776,6 @@ public class TestContainerLaunch extends BaseContainerManagerTest {
     String testKey3 = "MOUNT_LIST";
     String testVal3 = "/home/a/b/c,/home/d/e/f,/home/g/e/h";
     conf.set("yarn.nodemanager.admin-env." + testKey3, testVal3);
-    Map<String, String> environment = new HashMap<>();
-    LinkedHashSet<String> nmVars = new LinkedHashSet<>();
     ContainerLaunch launch = new ContainerLaunch(distContext, conf,
         dispatcher, exec, null, container, dirsHandler, containerManager);
     String testDir = System.getProperty("test.build.data",