YARN-2917. Fixed potential deadlock when system.exit is called in AsyncDispatcher. Contributed by Rohith Sharmaks

(cherry picked from commit 614b6afea450ebb897fbb2519c6f02e13b9bd12d)

(cherry picked from commit 41f0d20fcb4fec5b932b8947a44f93345205222c)
(cherry picked from commit aa4f8184ee7aa1817a9b23b3b4e7e78da95dc031)

hadoop-yarn-project/CHANGES.txt

@@ -42,6 +42,9 @@ Release 2.6.1 - UNRELEASED
     YARN-2910. FSLeafQueue can throw ConcurrentModificationException. 
     (Wilfred Spiegelenburg via kasha)
 
+    YARN-2917. Fixed potential deadlock when system.exit is called in AsyncDispatcher
+    (Rohith Sharmaks via jianhe)
+
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES

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

@@ -181,8 +181,9 @@ public class AsyncDispatcher extends AbstractService implements Dispatcher {
       if (exitOnDispatchException
           && (ShutdownHookManager.get().isShutdownInProgress()) == false
           && stopped == false) {
-        LOG.info("Exiting, bbye..");
-        System.exit(-1);
+        Thread shutDownThread = new Thread(createShutDownThread());
+        shutDownThread.setName("AsyncDispatcher ShutDown handler");
+        shutDownThread.start();
       }
     }
   }
@@ -271,4 +272,14 @@ public class AsyncDispatcher extends AbstractService implements Dispatcher {
     }
 
   }
+
+  Runnable createShutDownThread() {
+    return new Runnable() {
+      @Override
+      public void run() {
+        LOG.info("Exiting, bbye..");
+        System.exit(-1);
+      }
+    };
+  }
 }