From 439490f9158741234e638f41a5c0bdb236c4e988 Mon Sep 17 00:00:00 2001
From: Todd Lipcon <todd@apache.org>
Date: Tue, 14 Feb 2012 19:38:02 +0000
Subject: [PATCH] HDFS-2948. NN throws NPE during shutdown if it fails to
 startup. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-1623@1244186 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-1623.txt         | 2 ++
 .../java/org/apache/hadoop/hdfs/server/namenode/NameNode.java | 4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-1623.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-1623.txt
index 2eac773f96..d6eb3c83f7 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-1623.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-1623.txt
@@ -200,3 +200,5 @@ HDFS-2939. TestHAStateTransitions fails on Windows. (Uma Maheswara Rao G via atm
 HDFS-2947. On startup NN throws an NPE in the metrics system. (atm)
 
 HDFS-2942. TestActiveStandbyElectorRealZK fails if build dir does not exist. (atm)
+
+HDFS-2948. NN throws NPE during shutdown if it fails to startup (todd)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
index 2e7292229c..f1bfa74888 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
@@ -974,7 +974,9 @@ public void startActiveServices() throws IOException {
 
     @Override
     public void stopActiveServices() throws IOException {
-      namesystem.stopActiveServices();
+      if (namesystem != null) {
+        namesystem.stopActiveServices();
+      }
       stopTrashEmptier();
     }