From 9c00ae00091dcd9a2478cb2e1f440f963ff33d1f Mon Sep 17 00:00:00 2001
From: rohithsharmaks <rohithsharmaks@apache.org>
Date: Wed, 29 Jul 2015 23:44:15 +0530
Subject: [PATCH] YARN-3919. NPEs' while stopping service after exception
 during CommonNodeLabelsManager#start. (varun saxena via rohithsharmaks)

---
 hadoop-yarn-project/CHANGES.txt                           | 3 +++
 .../org/apache/hadoop/yarn/event/AsyncDispatcher.java     | 3 ++-
 .../hadoop/yarn/nodelabels/FileSystemNodeLabelsStore.java | 8 ++------
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index 5c356b6d819..ff36abca53b 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/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
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/event/AsyncDispatcher.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/event/AsyncDispatcher.java
index 48312a33e7c..f6701128ac6 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/event/AsyncDispatcher.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/event/AsyncDispatcher.java
@@ -139,7 +139,8 @@ protected void serviceStop() throws Exception {
       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());
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/FileSystemNodeLabelsStore.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/FileSystemNodeLabelsStore.java
index abf07e805a2..20dc67c10e4 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/nodelabels/FileSystemNodeLabelsStore.java
+++ b/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.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 void init(Configuration conf) throws Exception {
 
   @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 {