From 69f7277625b86a30a5964285d05dac4ba982e795 Mon Sep 17 00:00:00 2001
From: Jason Lowe <jlowe@apache.org>
Date: Mon, 29 Aug 2016 19:54:34 +0000
Subject: [PATCH] MAPREDUCE-6768. TestRecovery.testSpeculative failed with NPE.
 Contributed by Haibo Chen

---
 .../org/apache/hadoop/mapreduce/v2/app/TestRecovery.java  | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestRecovery.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestRecovery.java
index 4c6ee7284f..3ede2e92d5 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestRecovery.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestRecovery.java
@@ -25,6 +25,7 @@
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import com.google.common.base.Supplier;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -96,6 +97,7 @@
 import org.apache.hadoop.yarn.api.records.ContainerId;
 import org.apache.hadoop.yarn.api.records.Resource;
 import org.apache.hadoop.yarn.event.EventHandler;
+import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.yarn.util.Clock;
 import org.apache.hadoop.yarn.util.SystemClock;
 import org.junit.Test;
@@ -1196,6 +1198,12 @@ public void testSpeculative() throws Exception {
     TaskAttempt task1Attempt2 = t1it.next();
     TaskAttempt task2Attempt = mapTask2.getAttempts().values().iterator().next();
 
+    // wait for the second task attempt to be assigned.
+    GenericTestUtils.waitFor(new Supplier<Boolean>() {
+      @Override public Boolean get() {
+        return task1Attempt2.getAssignedContainerID() != null;
+      }
+    }, 10, 10000);
     ContainerId t1a2contId = task1Attempt2.getAssignedContainerID();
 
     LOG.info(t1a2contId.toString());