MAPREDUCE-6593. TestJobHistoryEventHandler.testTimelineEventHandling fails on trunk because of NPE. Contributed by Naganarasimha G R.

(cherry picked from commit 7dafee11d865c7c121c7886ac66aa9d088ea13f7)
(cherry picked from commit 6d235f0b91b9ba3041f5465f480278c33f01bd36)

hadoop-mapreduce-project/CHANGES.txt

@@ -379,6 +379,9 @@ Release 2.8.0 - UNRELEASED
     MAPREDUCE-6589. TestTaskLog outputs a log under directory other than
     target/test-dir. (aajisaka)
 
+    MAPREDUCE-6593. TestJobHistoryEventHandler.testTimelineEventHandling fails
+    on trunk because of NPE. (Naganarasimha G R via aajisaka)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/jobhistory/TestJobHistoryEventHandler.java

@@ -18,6 +18,7 @@
 
 package org.apache.hadoop.mapreduce.jobhistory;
 
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.mock;
@@ -31,8 +32,6 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.HashMap;
 
-import org.junit.Assert;
-
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
@@ -67,14 +66,14 @@ import org.apache.hadoop.yarn.api.records.timeline.TimelineEntities;
 import org.apache.hadoop.yarn.api.records.timeline.TimelineEntity;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
-import org.junit.After;
-import org.junit.AfterClass;
-import static org.junit.Assert.assertFalse;
-import org.junit.BeforeClass;
 import org.apache.hadoop.yarn.server.MiniYARNCluster;
 import org.apache.hadoop.yarn.server.timeline.TimelineStore;
 import org.codehaus.jackson.JsonNode;
 import org.codehaus.jackson.map.ObjectMapper;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.BeforeClass;
 import org.junit.Test;
 import org.mockito.Mockito;
 
@@ -854,6 +853,9 @@ class JHEvenHandlerForTest extends JobHistoryEventHandler {
 
   @Override
   protected void serviceStart() {
+    if (timelineClient != null) {
+      timelineClient.start();
+    }
   }
 
   @Override