HADOOP-11241. Fixed intermittent TestNMSimulator failure due to timing issue. Contributed by Varun Vasudev.

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -1039,6 +1039,9 @@ Release 2.6.0 - UNRELEASED
     HADOOP-11221. IdentityHashStore assumes System.identityHashCode() is
     non-negative. (Jinghui Wang via szetszwo)
 
+    HADOOP-11241. Fixed intermittent TestNMSimulator failure due to timing issue.
+    (Varun Vasudev via zjshen)
+
 Release 2.5.1 - 2014-09-05
 
   INCOMPATIBLE CHANGES

hadoop-tools/hadoop-sls/src/test/java/org/apache/hadoop/yarn/sls/nodemanager/TestNMSimulator.java

@@ -54,6 +54,16 @@ public class TestNMSimulator {
     node1.init("rack1/node1", GB * 10, 10, 0, 1000, rm);
     node1.middleStep();
 
+    int numClusterNodes = rm.getResourceScheduler().getNumClusterNodes();
+    int cumulativeSleepTime = 0;
+    int sleepInterval = 100;
+
+    while(numClusterNodes != 1 && cumulativeSleepTime < 5000) {
+      Thread.sleep(sleepInterval);
+      cumulativeSleepTime = cumulativeSleepTime + sleepInterval;
+      numClusterNodes = rm.getResourceScheduler().getNumClusterNodes();
+    }
+
     Assert.assertEquals(1, rm.getResourceScheduler().getNumClusterNodes());
     Assert.assertEquals(GB * 10,
         rm.getResourceScheduler().getRootQueueMetrics().getAvailableMB());