YARN-8729. Node status updater thread could be lost after it is restarted. Contributed by Tao Yang.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/NodeStatusUpdaterImpl.java

@@ -326,8 +326,8 @@ public class NodeStatusUpdaterImpl extends AbstractService implements
         statusUpdater.join();
         registerWithRM();
         statusUpdater = new Thread(statusUpdaterRunnable, "Node Status Updater");
-        statusUpdater.start();
         this.isStopped = false;
+        statusUpdater.start();
         LOG.info("NodeStatusUpdater thread is reRegistered and restarted");
       } catch (Exception e) {
         String errorMessage = "Unexpected error rebooting NodeStatusUpdater";