YARN-3919. NPEs' while stopping service after exception during CommonNodeLabelsManager#start. (varun saxena via rohithsharmaks)

hadoop-yarn-project/CHANGES.txt

@@ -655,6 +655,9 @@ Release 2.8.0 - UNRELEASED
     YARN-3982. container-executor parsing of container-executor.cfg broken in
     trunk and branch-2. (Varun Vasudev via xgong)
 
+    YARN-3919. NPEs' while stopping service after exception during
+    CommonNodeLabelsManager#start. (varun saxane via rohithsharmaks)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -139,7 +139,8 @@ public class AsyncDispatcher extends AbstractService implements Dispatcher {
       blockNewEvents = true;
       LOG.info("AsyncDispatcher is draining to stop, igonring any new events.");
       synchronized (waitForDrained) {
-        while (!drained && eventHandlingThread.isAlive()) {
+        while (!drained && eventHandlingThread != null
+            && eventHandlingThread.isAlive()) {
           waitForDrained.wait(1000);
           LOG.info("Waiting for AsyncDispatcher to drain. Thread state is :" +
               eventHandlingThread.getState());

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/FileSystemNodeLabelsStore.java

@@ -33,6 +33,7 @@ import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.LocalFileSystem;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.yarn.api.records.NodeId;
 import org.apache.hadoop.yarn.api.records.NodeLabel;
@@ -92,12 +93,7 @@ public class FileSystemNodeLabelsStore extends NodeLabelsStore {
 
   @Override
   public void close() throws IOException {
-    try {
-      fs.close();
-      editlogOs.close();
-    } catch (IOException e) {
-      LOG.warn("Exception happened whiling shutting down,", e);
-    }
+    IOUtils.cleanup(LOG, fs, editlogOs);
   }
 
   private void setFileSystem(Configuration conf) throws IOException {