diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestRuntimeEstimators.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestRuntimeEstimators.java
index fe0f34152b..69f2709144 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestRuntimeEstimators.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestRuntimeEstimators.java
@@ -69,13 +69,13 @@
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.ContainerId;
 import org.apache.hadoop.yarn.api.records.NodeId;
-import org.apache.hadoop.yarn.api.records.Token;
 import org.apache.hadoop.yarn.event.AsyncDispatcher;
 import org.apache.hadoop.yarn.event.EventHandler;
 import org.apache.hadoop.yarn.factories.RecordFactory;
 import org.apache.hadoop.yarn.factory.providers.RecordFactoryProvider;
 import org.apache.hadoop.yarn.security.client.ClientToAMTokenSecretManager;
 import org.apache.hadoop.yarn.util.Clock;
+import org.apache.hadoop.yarn.util.ControlledClock;
 import org.apache.hadoop.yarn.util.SystemClock;
 import org.junit.Assert;
 import org.junit.Test;
@@ -90,7 +90,7 @@ public class TestRuntimeEstimators {
   private static int MAP_TASKS = 200;
   private static int REDUCE_TASKS = 150;
 
-  MockClock clock;
+  ControlledClock clock;
 
   Job myJob;
 
@@ -120,7 +120,7 @@ public class TestRuntimeEstimators {
   private void coreTestEstimator
       (TaskRuntimeEstimator testedEstimator, int expectedSpeculations) {
     estimator = testedEstimator;
-	clock = new MockClock();
+	clock = new ControlledClock();
 	dispatcher = new AsyncDispatcher();
     myJob = null;
     slotsInUse.set(0);
@@ -129,7 +129,7 @@ public class TestRuntimeEstimators {
     successfulSpeculations.set(0);
     taskTimeSavedBySpeculation.set(0);
 
-    clock.advanceTime(1000);
+    clock.tickMsec(1000);
 
     Configuration conf = new Configuration();
 
@@ -230,7 +230,7 @@ public class TestRuntimeEstimators {
         }
       }
 
-      clock.advanceTime(1000L);
+      clock.tickMsec(1000L);
 
       if (clock.getTime() % 10000L == 0L) {
         speculator.scanForSpeculations();
@@ -777,22 +777,6 @@ public String getAssignedContainerMgrAddress() {
     }
   }
 
-  static class MockClock implements Clock {
-    private long currentTime = 0;
-
-    public long getTime() {
-      return currentTime;
-    }
-
-    void setMeasuredTime(long newTime) {
-      currentTime = newTime;
-    }
-
-    void advanceTime(long increment) {
-      currentTime += increment;
-    }
-  }
-
   class MyAppMaster extends CompositeService {
     final Clock clock;
       public MyAppMaster(Clock clock) {
diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index 8f07b794b3..ba73b2ef0f 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -218,6 +218,9 @@ Release 2.8.0 - UNRELEASED
     YARN-1912. ResourceLocalizer started without any jvm memory control.
     (Masatake Iwasaki via xgong)
 
+    YARN-1287. Consolidate MockClocks. 
+    (Sebastian Wong and Anubhav Dhoot via kasha)
+
   OPTIMIZATIONS
 
     YARN-3339. TestDockerContainerExecutor should pull a single image and not
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/util/ControlledClock.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/util/ControlledClock.java
index 16bd7856ce..6dcb1ddb80 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/util/ControlledClock.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/util/ControlledClock.java
@@ -21,6 +21,11 @@
 public class ControlledClock implements Clock {
   private long time = -1;
   private final Clock actualClock;
+  // Convenience for getting a controlled clock with overridden time
+  public ControlledClock() {
+    this(new SystemClock());
+    setTime(0);
+  }
   public ControlledClock(Clock actualClock) {
     this.actualClock = actualClock;
   }
@@ -30,6 +35,16 @@ public synchronized void setTime(long time) {
   public synchronized void reset() {
     time = -1;
   }
+  public synchronized void tickSec(int seconds) {
+    tickMsec(seconds * 1000L);
+  }
+  public synchronized void tickMsec(long millisec) {
+    if (time == -1) {
+      throw new IllegalStateException("ControlledClock setTime should be " +
+          "called before incrementing time");
+    }
+    time = time + millisec;
+  }
 
   @Override
   public synchronized long getTime() {
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/util/TestCgroupsLCEResourcesHandler.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/util/TestCgroupsLCEResourcesHandler.java
index 8e9d78709c..440f9ea5dc 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/util/TestCgroupsLCEResourcesHandler.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/util/TestCgroupsLCEResourcesHandler.java
@@ -22,10 +22,11 @@
 import org.apache.hadoop.yarn.api.records.Resource;
 import org.apache.hadoop.yarn.server.nodemanager.LinuxContainerExecutor;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.resources.TestCGroupsHandlerImpl;
+
+import org.apache.hadoop.yarn.util.ControlledClock;
 import org.apache.hadoop.yarn.util.ResourceCalculatorPlugin;
 import org.junit.Assert;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
-import org.apache.hadoop.yarn.util.Clock;
 import org.junit.Test;
 import org.junit.After;
 import org.junit.Before;
@@ -39,14 +40,6 @@
 public class TestCgroupsLCEResourcesHandler {
   static File cgroupDir = null;
 
-  static class MockClock implements Clock {
-    long time;
-    @Override
-    public long getTime() {
-      return time;
-    }
-  }
-
   @Before
   public void setUp() throws Exception {
     cgroupDir =
@@ -93,8 +86,7 @@ public void testcheckAndDeleteCgroup() throws Exception {
   // Verify DeleteCgroup times out if "tasks" file contains data
   @Test
   public void testDeleteCgroup() throws Exception {
-    final MockClock clock = new MockClock();
-    clock.time = System.currentTimeMillis();
+    final ControlledClock clock = new ControlledClock();
     CgroupsLCEResourcesHandler handler = new CgroupsLCEResourcesHandler();
     handler.setConf(new YarnConfiguration());
     handler.initConfig();
@@ -118,8 +110,8 @@ public void run() {
         } catch (InterruptedException ex) {
           //NOP
         }
-        clock.time += YarnConfiguration.
-            DEFAULT_NM_LINUX_CONTAINER_CGROUPS_DELETE_TIMEOUT;
+        clock.tickMsec(YarnConfiguration.
+            DEFAULT_NM_LINUX_CONTAINER_CGROUPS_DELETE_TIMEOUT);
       }
     }.start();
     latch.await();
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairSchedulerTestBase.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairSchedulerTestBase.java
index 0a9c389556..23b708add2 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairSchedulerTestBase.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairSchedulerTestBase.java
@@ -49,18 +49,6 @@
 import org.apache.hadoop.yarn.util.Clock;
 
 public class FairSchedulerTestBase {
-  protected static class MockClock implements Clock {
-    private long time = 0;
-    @Override
-    public long getTime() {
-      return time;
-    }
-
-    public void tick(int seconds) {
-      time = time + seconds * 1000;
-    }
-  }
-
   public final static String TEST_DIR =
       new File(System.getProperty("test.build.data", "/tmp")).getAbsolutePath();
 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestAllocationFileLoaderService.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestAllocationFileLoaderService.java
index b09573cd8c..202eb09c77 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestAllocationFileLoaderService.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestAllocationFileLoaderService.java
@@ -31,7 +31,7 @@
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.QueuePlacementRule.NestedUserQueue;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.policies.DominantResourceFairnessPolicy;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.policies.FairSharePolicy;
-import org.apache.hadoop.yarn.util.Clock;
+import org.apache.hadoop.yarn.util.ControlledClock;
 import org.apache.hadoop.yarn.util.resource.Resources;
 import org.junit.Test;
 
@@ -43,18 +43,6 @@ public class TestAllocationFileLoaderService {
   final static String ALLOC_FILE = new File(TEST_DIR,
       "test-queues").getAbsolutePath();
   
-  private class MockClock implements Clock {
-    private long time = 0;
-    @Override
-    public long getTime() {
-      return time;
-    }
-
-    public void tick(long ms) {
-      time += ms;
-    }
-  }
-  
   @Test
   public void testGetAllocationFileFromClasspath() {
     Configuration conf = new Configuration();
@@ -81,7 +69,8 @@ public void testReload() throws Exception {
     out.println("</allocations>");
     out.close();
     
-    MockClock clock = new MockClock();
+    ControlledClock clock = new ControlledClock();
+    clock.setTime(0);
     Configuration conf = new Configuration();
     conf.set(FairSchedulerConfiguration.ALLOCATION_FILE, ALLOC_FILE);
 
@@ -126,7 +115,7 @@ public void testReload() throws Exception {
     out.println("</allocations>");
     out.close();
     
-    clock.tick(System.currentTimeMillis()
+    clock.tickMsec(System.currentTimeMillis()
         + AllocationFileLoaderService.ALLOC_RELOAD_WAIT_MS + 10000);
     allocLoader.start();
     
diff --git a/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 b/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
index a72e3938f4..53382de9c8 100644
--- a/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
+++ b/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
@@ -19,20 +19,16 @@
 package org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair;
 
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.metrics2.lib.MutableRate;
-import org.apache.hadoop.metrics2.util.SampleStat;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ContainerId;
-import org.apache.hadoop.yarn.api.records.Resource;
 import org.apache.hadoop.yarn.api.records.ResourceRequest;
 import org.apache.hadoop.yarn.server.resourcemanager.MockNodes;
 import org.apache.hadoop.yarn.server.resourcemanager.MockRM;
-import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppImpl;
 import org.apache.hadoop.yarn.server.resourcemanager.rmnode.RMNode;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.event.NodeAddedSchedulerEvent;
 
-import org.apache.hadoop.yarn.server.resourcemanager.scheduler.event
-    .NodeUpdateSchedulerEvent;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.event.NodeUpdateSchedulerEvent;
+import org.apache.hadoop.yarn.util.ControlledClock;
 import org.apache.hadoop.yarn.util.resource.Resources;
 import org.junit.After;
 import static org.junit.Assert.assertEquals;
@@ -41,11 +37,10 @@
 import org.junit.Test;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 public class TestContinuousScheduling extends FairSchedulerTestBase {
-  private MockClock mockClock;
+  private ControlledClock mockClock;
 
   @Override
   public Configuration createConfiguration() {
@@ -59,7 +54,7 @@ public Configuration createConfiguration() {
 
   @Before
   public void setup() {
-    mockClock = new MockClock();
+    mockClock = new ControlledClock();
     conf = createConfiguration();
     resourceManager = new MockRM(conf);
     resourceManager.start();
@@ -108,7 +103,7 @@ public void testSchedulingDelay() throws InterruptedException {
     FSAppAttempt app = scheduler.getSchedulerApp(appAttemptId);
 
     // Advance time and let continuous scheduling kick in
-    mockClock.tick(1);
+    mockClock.tickSec(1);
     while (1024 != app.getCurrentConsumption().getMemory()) {
       Thread.sleep(100);
     }
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFSAppAttempt.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFSAppAttempt.java
index 43fe186d7c..7aa62a8e44 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFSAppAttempt.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFSAppAttempt.java
@@ -31,7 +31,8 @@
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.policies.DominantResourceFairnessPolicy;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.policies.FairSharePolicy;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.policies.FifoPolicy;
-import org.apache.hadoop.yarn.util.Clock;
+
+import org.apache.hadoop.yarn.util.ControlledClock;
 import org.apache.hadoop.yarn.util.resource.Resources;
 import org.junit.Before;
 import org.junit.Test;
@@ -39,19 +40,6 @@
 
 public class TestFSAppAttempt extends FairSchedulerTestBase {
 
-  private class MockClock implements Clock {
-    private long time = 0;
-    @Override
-    public long getTime() {
-      return time;
-    }
-
-    public void tick(int seconds) {
-      time = time + seconds * 1000;
-    }
-
-  }
-
   @Before
   public void setup() {
     Configuration conf = createConfiguration();
@@ -125,7 +113,7 @@ public void testDelaySchedulingForContinuousScheduling()
     Priority prio = Mockito.mock(Priority.class);
     Mockito.when(prio.getPriority()).thenReturn(1);
 
-    MockClock clock = new MockClock();
+    ControlledClock clock = new ControlledClock();
     scheduler.setClock(clock);
 
     long nodeLocalityDelayMs = 5 * 1000L;    // 5 seconds
@@ -143,13 +131,13 @@ public void testDelaySchedulingForContinuousScheduling()
                     nodeLocalityDelayMs, rackLocalityDelayMs, clock.getTime()));
 
     // after 4 seconds should remain node local
-    clock.tick(4);
+    clock.tickSec(4);
     assertEquals(NodeType.NODE_LOCAL,
             schedulerApp.getAllowedLocalityLevelByTime(prio,
                     nodeLocalityDelayMs, rackLocalityDelayMs, clock.getTime()));
 
     // after 6 seconds should switch to rack local
-    clock.tick(2);
+    clock.tickSec(2);
     assertEquals(NodeType.RACK_LOCAL,
             schedulerApp.getAllowedLocalityLevelByTime(prio,
                     nodeLocalityDelayMs, rackLocalityDelayMs, clock.getTime()));
@@ -162,12 +150,12 @@ public void testDelaySchedulingForContinuousScheduling()
                     nodeLocalityDelayMs, rackLocalityDelayMs, clock.getTime()));
 
     // Now escalate again to rack-local, then to off-switch
-    clock.tick(6);
+    clock.tickSec(6);
     assertEquals(NodeType.RACK_LOCAL,
             schedulerApp.getAllowedLocalityLevelByTime(prio,
                     nodeLocalityDelayMs, rackLocalityDelayMs, clock.getTime()));
 
-    clock.tick(7);
+    clock.tickSec(7);
     assertEquals(NodeType.OFF_SWITCH,
             schedulerApp.getAllowedLocalityLevelByTime(prio,
                     nodeLocalityDelayMs, rackLocalityDelayMs, clock.getTime()));
diff --git a/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 b/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
index fc69de71a4..a26209b0b5 100644
--- a/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
+++ b/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
@@ -72,7 +72,6 @@
 import org.apache.hadoop.yarn.server.resourcemanager.ApplicationMasterService;
 import org.apache.hadoop.yarn.server.resourcemanager.MockNodes;
 import org.apache.hadoop.yarn.server.resourcemanager.MockRM;
-import org.apache.hadoop.yarn.server.resourcemanager.ResourceManager;
 import org.apache.hadoop.yarn.server.resourcemanager.resource.ResourceType;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.MockRMApp;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
@@ -100,6 +99,8 @@
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.policies.DominantResourceFairnessPolicy;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.policies.FifoPolicy;
 import org.apache.hadoop.yarn.server.utils.BuilderUtils;
+import org.apache.hadoop.yarn.util.ControlledClock;
+import org.apache.hadoop.yarn.util.SystemClock;
 import org.apache.hadoop.yarn.util.resource.Resources;
 import org.junit.After;
 import org.junit.Assert;
@@ -1489,7 +1490,7 @@ public void testChoiceOfPreemptedContainers() throws Exception {
     conf.set(FairSchedulerConfiguration.ALLOCATION_FILE + ".allocation.file", ALLOC_FILE);
     conf.set(FairSchedulerConfiguration.USER_AS_DEFAULT_QUEUE, "false");
     
-    MockClock clock = new MockClock();
+    ControlledClock clock = new ControlledClock();
     scheduler.setClock(clock);
     
     PrintWriter out = new PrintWriter(new FileWriter(ALLOC_FILE));
@@ -1587,7 +1588,7 @@ public void testChoiceOfPreemptedContainers() throws Exception {
             scheduler.getSchedulerApp(app2).getPreemptionContainers()));
 
     // Pretend 15 seconds have passed
-    clock.tick(15);
+    clock.tickSec(15);
 
     // Trigger a kill by insisting we want containers back
     scheduler.preemptResources(Resources.createResource(2 * 1024));
@@ -1617,7 +1618,7 @@ public void testChoiceOfPreemptedContainers() throws Exception {
     scheduler.preemptResources(Resources.createResource(2 * 1024));
 
     // Pretend 15 seconds have passed
-    clock.tick(15);
+    clock.tickSec(15);
 
     // We should be able to claw back another container from A and B each.
     // For queueA (fifo), continue preempting from app2.
@@ -1649,7 +1650,7 @@ public void testPreemptionIsNotDelayedToNextRound() throws Exception {
     conf.set(FairSchedulerConfiguration.ALLOCATION_FILE, ALLOC_FILE);
     conf.set(FairSchedulerConfiguration.USER_AS_DEFAULT_QUEUE, "false");
 
-    MockClock clock = new MockClock();
+    ControlledClock clock = new ControlledClock();
     scheduler.setClock(clock);
 
     PrintWriter out = new PrintWriter(new FileWriter(ALLOC_FILE));
@@ -1702,7 +1703,7 @@ public void testPreemptionIsNotDelayedToNextRound() throws Exception {
     scheduler.update();
 
     // Let 11 sec pass
-    clock.tick(11);
+    clock.tickSec(11);
 
     scheduler.update();
     Resource toPreempt = scheduler.resToPreempt(scheduler.getQueueManager()
@@ -1722,7 +1723,7 @@ public void testPreemptionIsNotDelayedToNextRound() throws Exception {
    */
   public void testPreemptionDecision() throws Exception {
     conf.set(FairSchedulerConfiguration.ALLOCATION_FILE, ALLOC_FILE);
-    MockClock clock = new MockClock();
+    ControlledClock clock = new ControlledClock();
     scheduler.setClock(clock);
 
     PrintWriter out = new PrintWriter(new FileWriter(ALLOC_FILE));
@@ -1833,7 +1834,7 @@ public void testPreemptionDecision() throws Exception {
         Resources.none(), scheduler.resToPreempt(schedD, clock.getTime())));
     // After minSharePreemptionTime has passed, they should want to preempt min
     // share.
-    clock.tick(6);
+    clock.tickSec(6);
     assertEquals(
         1024, scheduler.resToPreempt(schedC, clock.getTime()).getMemory());
     assertEquals(
@@ -1842,7 +1843,7 @@ public void testPreemptionDecision() throws Exception {
     // After fairSharePreemptionTime has passed, they should want to preempt
     // fair share.
     scheduler.update();
-    clock.tick(6);
+    clock.tickSec(6);
     assertEquals(
         1536 , scheduler.resToPreempt(schedC, clock.getTime()).getMemory());
     assertEquals(
@@ -1855,7 +1856,7 @@ public void testPreemptionDecision() throws Exception {
    */
   public void testPreemptionDecisionWithVariousTimeout() throws Exception {
     conf.set(FairSchedulerConfiguration.ALLOCATION_FILE, ALLOC_FILE);
-    MockClock clock = new MockClock();
+    ControlledClock clock = new ControlledClock();
     scheduler.setClock(clock);
 
     PrintWriter out = new PrintWriter(new FileWriter(ALLOC_FILE));
@@ -1971,7 +1972,7 @@ public void testPreemptionDecisionWithVariousTimeout() throws Exception {
 
     // After 5 seconds, queueB1 wants to preempt min share
     scheduler.update();
-    clock.tick(6);
+    clock.tickSec(6);
     assertEquals(
        1024, scheduler.resToPreempt(queueB1, clock.getTime()).getMemory());
     assertEquals(
@@ -1981,7 +1982,7 @@ public void testPreemptionDecisionWithVariousTimeout() throws Exception {
 
     // After 10 seconds, queueB2 wants to preempt min share
     scheduler.update();
-    clock.tick(5);
+    clock.tickSec(5);
     assertEquals(
         1024, scheduler.resToPreempt(queueB1, clock.getTime()).getMemory());
     assertEquals(
@@ -1991,7 +1992,7 @@ public void testPreemptionDecisionWithVariousTimeout() throws Exception {
 
     // After 15 seconds, queueC wants to preempt min share
     scheduler.update();
-    clock.tick(5);
+    clock.tickSec(5);
     assertEquals(
         1024, scheduler.resToPreempt(queueB1, clock.getTime()).getMemory());
     assertEquals(
@@ -2001,7 +2002,7 @@ public void testPreemptionDecisionWithVariousTimeout() throws Exception {
 
     // After 20 seconds, queueB2 should want to preempt fair share
     scheduler.update();
-    clock.tick(5);
+    clock.tickSec(5);
     assertEquals(
         1024, scheduler.resToPreempt(queueB1, clock.getTime()).getMemory());
     assertEquals(
@@ -2011,7 +2012,7 @@ public void testPreemptionDecisionWithVariousTimeout() throws Exception {
 
     // After 25 seconds, queueB1 should want to preempt fair share
     scheduler.update();
-    clock.tick(5);
+    clock.tickSec(5);
     assertEquals(
         1536, scheduler.resToPreempt(queueB1, clock.getTime()).getMemory());
     assertEquals(
@@ -2021,7 +2022,7 @@ public void testPreemptionDecisionWithVariousTimeout() throws Exception {
 
     // After 30 seconds, queueC should want to preempt fair share
     scheduler.update();
-    clock.tick(5);
+    clock.tickSec(5);
     assertEquals(
         1536, scheduler.resToPreempt(queueB1, clock.getTime()).getMemory());
     assertEquals(
@@ -3703,7 +3704,7 @@ public void testQueueMaxAMShareDefault() throws Exception {
   @Test
   public void testMaxRunningAppsHierarchicalQueues() throws Exception {
     conf.set(FairSchedulerConfiguration.ALLOCATION_FILE, ALLOC_FILE);
-    MockClock clock = new MockClock();
+    ControlledClock clock = new ControlledClock();
     scheduler.setClock(clock);
 
     PrintWriter out = new PrintWriter(new FileWriter(ALLOC_FILE));
@@ -3728,28 +3729,28 @@ public void testMaxRunningAppsHierarchicalQueues() throws Exception {
     ApplicationAttemptId attId1 = createSchedulingRequest(1024, "queue1.sub1", "user1");
     verifyAppRunnable(attId1, true);
     verifyQueueNumRunnable("queue1.sub1", 1, 0);
-    clock.tick(10);
+    clock.tickSec(10);
     // exceeds no limits
     ApplicationAttemptId attId2 = createSchedulingRequest(1024, "queue1.sub3", "user1");
     verifyAppRunnable(attId2, true);
     verifyQueueNumRunnable("queue1.sub3", 1, 0);
-    clock.tick(10);
+    clock.tickSec(10);
     // exceeds no limits
     ApplicationAttemptId attId3 = createSchedulingRequest(1024, "queue1.sub2", "user1");
     verifyAppRunnable(attId3, true);
     verifyQueueNumRunnable("queue1.sub2", 1, 0);
-    clock.tick(10);
+    clock.tickSec(10);
     // exceeds queue1 limit
     ApplicationAttemptId attId4 = createSchedulingRequest(1024, "queue1.sub2", "user1");
     verifyAppRunnable(attId4, false);
     verifyQueueNumRunnable("queue1.sub2", 1, 1);
-    clock.tick(10);
+    clock.tickSec(10);
     // exceeds sub3 limit
     ApplicationAttemptId attId5 = createSchedulingRequest(1024, "queue1.sub3", "user1");
     verifyAppRunnable(attId5, false);
     verifyQueueNumRunnable("queue1.sub3", 1, 1);
-    clock.tick(10);
-    
+    clock.tickSec(10);
+
     // Even though the app was removed from sub3, the app from sub2 gets to go
     // because it came in first
     AppAttemptRemovedSchedulerEvent appRemovedEvent1 =
@@ -3923,7 +3924,7 @@ public void testDefaultRuleInitializesProperlyWhenPolicyNotConfigured()
   public void testRecoverRequestAfterPreemption() throws Exception {
     conf.setLong(FairSchedulerConfiguration.WAIT_TIME_BEFORE_KILL, 10);
     
-    MockClock clock = new MockClock();
+    ControlledClock clock = new ControlledClock();
     scheduler.setClock(clock);
     scheduler.init(conf);
     scheduler.start();
@@ -3974,8 +3975,8 @@ public void testRecoverRequestAfterPreemption() throws Exception {
     scheduler.warnOrKillContainer(rmContainer);
     
     // Wait for few clock ticks
-    clock.tick(5);
-    
+    clock.tickSec(5);
+
     // preempt now
     scheduler.warnOrKillContainer(rmContainer);
 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairSchedulerPreemption.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairSchedulerPreemption.java
index 458b06dd60..6f759ce336 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairSchedulerPreemption.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairSchedulerPreemption.java
@@ -26,6 +26,8 @@
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.event.NodeAddedSchedulerEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.event.NodeUpdateSchedulerEvent;
+
+import org.apache.hadoop.yarn.util.ControlledClock;
 import org.apache.hadoop.yarn.util.resource.Resources;
 import org.junit.After;
 import org.junit.Before;
@@ -43,7 +45,7 @@ public class TestFairSchedulerPreemption extends FairSchedulerTestBase {
   private final static String ALLOC_FILE = new File(TEST_DIR,
       TestFairSchedulerPreemption.class.getName() + ".xml").getAbsolutePath();
 
-  private MockClock clock;
+  private ControlledClock clock;
 
   private static class StubbedFairScheduler extends FairScheduler {
     public int lastPreemptMemory = -1;
@@ -70,7 +72,7 @@ public Configuration createConfiguration() {
   @Before
   public void setup() throws IOException {
     conf = createConfiguration();
-    clock = new MockClock();
+    clock = new ControlledClock();
   }
 
   @After
@@ -148,7 +150,7 @@ public void testPreemptionWithFreeResources() throws Exception {
     // Verify submitting another request triggers preemption
     createSchedulingRequest(1024, "queueB", "user1", 1, 1);
     scheduler.update();
-    clock.tick(6);
+    clock.tickSec(6);
 
     ((StubbedFairScheduler) scheduler).resetLastPreemptResources();
     scheduler.preemptTasksIfNecessary();
@@ -164,7 +166,7 @@ public void testPreemptionWithFreeResources() throws Exception {
     // Verify submitting another request doesn't trigger preemption
     createSchedulingRequest(1024, "queueB", "user1", 1, 1);
     scheduler.update();
-    clock.tick(6);
+    clock.tickSec(6);
 
     ((StubbedFairScheduler) scheduler).resetLastPreemptResources();
     scheduler.preemptTasksIfNecessary();
@@ -180,7 +182,7 @@ public void testPreemptionWithFreeResources() throws Exception {
     // Verify submitting another request triggers preemption
     createSchedulingRequest(1024, "queueB", "user1", 1, 1);
     scheduler.update();
-    clock.tick(6);
+    clock.tickSec(6);
 
     ((StubbedFairScheduler) scheduler).resetLastPreemptResources();
     scheduler.preemptTasksIfNecessary();
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestMaxRunningAppsEnforcer.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestMaxRunningAppsEnforcer.java
index ac5748f8c2..6cca19a38d 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestMaxRunningAppsEnforcer.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestMaxRunningAppsEnforcer.java
@@ -31,6 +31,7 @@
 import org.apache.hadoop.yarn.server.resourcemanager.RMContext;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.util.ControlledClock;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -40,14 +41,14 @@ public class TestMaxRunningAppsEnforcer {
   private Map<String, Integer> userMaxApps;
   private MaxRunningAppsEnforcer maxAppsEnforcer;
   private int appNum;
-  private TestFairScheduler.MockClock clock;
+  private ControlledClock clock;
   private RMContext rmContext;
   private FairScheduler scheduler;
   
   @Before
   public void setup() throws Exception {
     Configuration conf = new Configuration();
-    clock = new TestFairScheduler.MockClock();
+    clock = new ControlledClock();
     scheduler = mock(FairScheduler.class);
     when(scheduler.getConf()).thenReturn(
         new FairSchedulerConfiguration(conf));
@@ -151,7 +152,7 @@ public void testRemoveEnablingOrderedByStartTime() {
     FSAppAttempt app1 = addApp(leaf1, "user");
     addApp(leaf2, "user");
     addApp(leaf2, "user");
-    clock.tick(20);
+    clock.tickSec(20);
     addApp(leaf1, "user");
     assertEquals(1, leaf1.getNumRunnableApps());
     assertEquals(1, leaf2.getNumRunnableApps());