From f5ef0442b02da0c530a3077f3126484a9e59f147 Mon Sep 17 00:00:00 2001
From: lujie <lujie@ict.ac.cn>
Date: Mon, 18 Feb 2019 02:55:13 -0800
Subject: [PATCH] HBASE-21740 Fix NPE while shutting down RS

---
 .../org/apache/hadoop/hbase/regionserver/HRegionServer.java   | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java
index 371915fbb34..fea0a8f6ba9 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java
@@ -1946,7 +1946,9 @@ public class HRegionServer extends HasThread implements
 
     Threads.setDaemonThreadRunning(this.walRoller.getThread(), getName() + ".logRoller",
     uncaughtExceptionHandler);
-    this.cacheFlusher.start(uncaughtExceptionHandler);
+    if (this.cacheFlusher != null) {
+      this.cacheFlusher.start(uncaughtExceptionHandler);
+    }
     Threads.setDaemonThreadRunning(this.procedureResultReporter,
       getName() + ".procedureResultReporter", uncaughtExceptionHandler);