MAPREDUCE-4785. TestMRApp occasionally fails (haibochen via rkanter)

(cherry picked from commit ff0ee84d77)
(cherry picked from commit f9f57265cf)

Conflicts:
	hadoop-mapreduce-project/CHANGES.txt

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestMRApp.java

@@ -25,7 +25,10 @@ import static org.mockito.Mockito.verify;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
+import java.util.concurrent.TimeoutException;
 
+import com.google.common.base.Supplier;
+import org.apache.hadoop.test.GenericTestUtils;
 import org.junit.Assert;
 
 import org.apache.hadoop.conf.Configuration;
@@ -205,10 +208,10 @@ public class TestMRApp {
     conf.setFloat(MRJobConfig.COMPLETED_MAPS_FOR_REDUCE_SLOWSTART, 0.5f);
     // uberization forces full slowstart (1.0), so disable that
     conf.setBoolean(MRJobConfig.JOB_UBERTASK_ENABLE, false);
-    Job job = app.submit(conf);
-    app.waitForState(job, JobState.RUNNING);
-    Assert.assertEquals("Num tasks not correct", 4, job.getTasks().size());
-    Iterator<Task> it = job.getTasks().values().iterator();
+    final Job job1 = app.submit(conf);
+    app.waitForState(job1, JobState.RUNNING);
+    Assert.assertEquals("Num tasks not correct", 4, job1.getTasks().size());
+    Iterator<Task> it = job1.getTasks().values().iterator();
     Task mapTask1 = it.next();
     Task mapTask2 = it.next();
 
@@ -240,8 +243,20 @@ public class TestMRApp {
     app.waitForState(mapTask1, TaskState.SUCCEEDED);
     app.waitForState(mapTask2, TaskState.SUCCEEDED);
 
-    TaskAttemptCompletionEvent[] events = job.getTaskAttemptCompletionEvents(0,
-        100);
+    final int checkIntervalMillis = 100;
+    final int waitForMillis = 800;
+
+    waitFor(new Supplier<Boolean>() {
+      @Override
+      public Boolean get() {
+        TaskAttemptCompletionEvent[] events = job1
+            .getTaskAttemptCompletionEvents(0, 100);
+        return events.length == 2;
+      }
+    }, checkIntervalMillis, waitForMillis);
+
+    TaskAttemptCompletionEvent[] events = job1.getTaskAttemptCompletionEvents
+        (0, 100);
     Assert.assertEquals("Expecting 2 completion events for success", 2,
         events.length);
 
@@ -253,12 +268,21 @@ public class TestMRApp {
     nr.setNodeState(NodeState.UNHEALTHY);
     updatedNodes.add(nr);
     app.getContext().getEventHandler()
-        .handle(new JobUpdatedNodesEvent(job.getID(), updatedNodes));
+        .handle(new JobUpdatedNodesEvent(job1.getID(), updatedNodes));
 
     app.waitForState(task1Attempt, TaskAttemptState.KILLED);
     app.waitForState(task2Attempt, TaskAttemptState.KILLED);
 
-    events = job.getTaskAttemptCompletionEvents(0, 100);
+    waitFor(new Supplier<Boolean>() {
+      @Override
+      public Boolean get() {
+        TaskAttemptCompletionEvent[] events = job1
+            .getTaskAttemptCompletionEvents(0, 100);
+        return events.length == 4;
+      }
+    }, checkIntervalMillis, waitForMillis);
+
+    events = job1.getTaskAttemptCompletionEvents(0, 100);
     Assert.assertEquals("Expecting 2 more completion events for killed", 4,
         events.length);
 
@@ -281,7 +305,16 @@ public class TestMRApp {
     app.waitForState(mapTask1, TaskState.SUCCEEDED);
     app.waitForState(mapTask2, TaskState.RUNNING);
 
-    events = job.getTaskAttemptCompletionEvents(0, 100);
+    waitFor(new Supplier<Boolean>() {
+      @Override
+      public Boolean get() {
+        TaskAttemptCompletionEvent[] events = job1
+            .getTaskAttemptCompletionEvents(0, 100);
+        return events.length == 5;
+      }
+    }, checkIntervalMillis, waitForMillis);
+
+    events = job1.getTaskAttemptCompletionEvents(0, 100);
     Assert.assertEquals("Expecting 1 more completion events for success", 5,
         events.length);
 
@@ -295,10 +328,11 @@ public class TestMRApp {
     conf = new Configuration();
     conf.setBoolean(MRJobConfig.MR_AM_JOB_RECOVERY_ENABLE, true);
     conf.setBoolean(MRJobConfig.JOB_UBERTASK_ENABLE, false);
-    job = app.submit(conf);
-    app.waitForState(job, JobState.RUNNING);
-    Assert.assertEquals("No of tasks not correct", 4, job.getTasks().size());
-    it = job.getTasks().values().iterator();
+
+    final Job job2 = app.submit(conf);
+    app.waitForState(job2, JobState.RUNNING);
+    Assert.assertEquals("No of tasks not correct", 4, job2.getTasks().size());
+    it = job2.getTasks().values().iterator();
     mapTask1 = it.next();
     mapTask2 = it.next();
     Task reduceTask1 = it.next();
@@ -308,7 +342,16 @@ public class TestMRApp {
     app.waitForState(mapTask1, TaskState.SUCCEEDED);
     app.waitForState(mapTask2, TaskState.RUNNING);
 
-    events = job.getTaskAttemptCompletionEvents(0, 100);
+    waitFor(new Supplier<Boolean>() {
+      @Override
+      public Boolean get() {
+        TaskAttemptCompletionEvent[] events = job2
+            .getTaskAttemptCompletionEvents(0, 100);
+        return events.length == 2;
+      }
+    }, checkIntervalMillis, waitForMillis);
+
+    events = job2.getTaskAttemptCompletionEvents(0, 100);
     Assert.assertEquals(
         "Expecting 2 completion events for killed & success of map1", 2,
         events.length);
@@ -321,7 +364,16 @@ public class TestMRApp {
                 TaskAttemptEventType.TA_DONE));
     app.waitForState(mapTask2, TaskState.SUCCEEDED);
 
-    events = job.getTaskAttemptCompletionEvents(0, 100);
+    waitFor(new Supplier<Boolean>() {
+      @Override
+      public Boolean get() {
+        TaskAttemptCompletionEvent[] events = job2
+            .getTaskAttemptCompletionEvents(0, 100);
+        return events.length == 3;
+      }
+    }, checkIntervalMillis, waitForMillis);
+
+    events = job2.getTaskAttemptCompletionEvents(0, 100);
     Assert.assertEquals("Expecting 1 more completion events for success", 3,
         events.length);
 
@@ -352,12 +404,28 @@ public class TestMRApp {
                 TaskAttemptEventType.TA_DONE));
     app.waitForState(reduceTask2, TaskState.SUCCEEDED);
 
-    events = job.getTaskAttemptCompletionEvents(0, 100);
+    waitFor(new Supplier<Boolean>() {
+      @Override
+      public Boolean get() {
+        TaskAttemptCompletionEvent[] events = job2
+            .getTaskAttemptCompletionEvents(0, 100);
+        return events.length == 5;
+      }
+    }, checkIntervalMillis, waitForMillis);
+    events = job2.getTaskAttemptCompletionEvents(0, 100);
     Assert.assertEquals("Expecting 2 more completion events for reduce success",
         5, events.length);
 
     // job succeeds
-    app.waitForState(job, JobState.SUCCEEDED);
+    app.waitForState(job2, JobState.SUCCEEDED);
+  }
+
+  private static void waitFor(Supplier<Boolean> predicate, int
+      checkIntervalMillis, int checkTotalMillis) throws InterruptedException {
+    try {
+      GenericTestUtils.waitFor(predicate, checkIntervalMillis, checkTotalMillis);
+    } catch (TimeoutException ex) {
+    }
   }
 
   @Test