svn merge -c 1353038 FIXES: MAPREDUCE-4031. Prevent a Node Manager hang during shutdown. (Contributed by Devaraj K)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1356977 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ShutdownHookManager.java

@@ -30,7 +30,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * The <code>ShutdownHookManager</code> enables running shutdownHook
- * in a determistic order, higher priority first.
+ * in a deterministic order, higher priority first.
  * <p/>
  * The JVM runs ShutdownHooks in a non-deterministic order or in parallel.
  * This class registers a single JVM shutdownHook and run all the
@@ -169,7 +169,7 @@ public class ShutdownHookManager {
   }
 
   /**
-   * Indicates if a shutdownHook is registered or nt.
+   * Indicates if a shutdownHook is registered or not.
    *
    * @param shutdownHook shutdownHook to check if registered.
    * @return TRUE/FALSE depending if the shutdownHook is is registered.
@@ -177,5 +177,14 @@ public class ShutdownHookManager {
   public boolean hasShutdownHook(Runnable shutdownHook) {
     return hooks.contains(new HookEntry(shutdownHook, 0));
   }
+  
+  /**
+   * Indicates if shutdown is in progress or not.
+   * 
+   * @return TRUE if the shutdown is in progress, otherwise FALSE.
+   */
+  public boolean isShutdownInProgress() {
+    return shutdownInProgress.get();
+  }
 
 }

hadoop-mapreduce-project/CHANGES.txt

@@ -270,6 +270,9 @@ Release 0.23.3 - UNRELEASED
     MAPREDUCE-4205. retrofit all JVM shutdown hooks to use ShutdownHookManager 
     (tucu)
 
+    MAPREDUCE-4031. Prevent a Node Manager hang during shutdown. 
+    (Devaraj K via sseth)
+
 Release 0.23.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/event/AsyncDispatcher.java

@@ -28,6 +28,7 @@ import java.util.concurrent.LinkedBlockingQueue;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.util.ShutdownHookManager;
 import org.apache.hadoop.yarn.YarnException;
 import org.apache.hadoop.yarn.service.AbstractService;
 
@@ -127,7 +128,8 @@ public class AsyncDispatcher extends AbstractService implements Dispatcher {
     catch (Throwable t) {
       //TODO Maybe log the state of the queue
       LOG.fatal("Error in dispatcher thread", t);
-      if (exitOnDispatchException) {
+      if (exitOnDispatchException
+          && (ShutdownHookManager.get().isShutdownInProgress()) == false) {
         LOG.info("Exiting, bbye..");
         System.exit(-1);
       }