YARN-10297. TestContinuousScheduling#testFairSchedulerContinuousSchedulingInitTime fails intermittently. Contributed by Jim Brennan (Jim_Brennan)

(cherry picked from commit 0427100b7543d412f4fafe631b7ace289662d28c)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestContinuousScheduling.java

@@ -19,6 +19,7 @@
 package org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ContainerId;
 import org.apache.hadoop.yarn.api.records.NodeId;
@@ -32,6 +33,7 @@ import org.apache.hadoop.yarn.server.resourcemanager.MockRM;
 import org.apache.hadoop.yarn.server.resourcemanager.rmcontainer.RMContainer;
 import org.apache.hadoop.yarn.server.resourcemanager.rmnode.RMNode;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ClusterNodeTracker;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.QueueMetrics;
 import org.apache.hadoop.yarn.server.scheduler.SchedulerRequestKey;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.TestUtils;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.event.NodeAddedSchedulerEvent;
@@ -82,6 +84,9 @@ public class TestContinuousScheduling extends FairSchedulerTestBase {
   @SuppressWarnings("deprecation")
   @Before
   public void setup() {
+    QueueMetrics.clearQueueMetrics();
+    DefaultMetricsSystem.setMiniClusterMode(true);
+    
     mockClock = new ControlledClock();
     conf = createConfiguration();
     resourceManager = new MockRM(conf);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairScheduler.java

@@ -135,6 +135,7 @@ public class TestFairScheduler extends FairSchedulerTestBase {
 
   @Before
   public void setUp() throws IOException {
+    DefaultMetricsSystem.setMiniClusterMode(true);
     scheduler = new FairScheduler();
     conf = createConfiguration();
     resourceManager = new MockRM(conf);