@Test(timeout = 60000)
public void testResourceOverCommit() throws Exception {

  int waitCount;
  MockRM rm = new MockRM(conf);
  rm.start();
  MockNM nm1 = rm.registerNode("127.0.0.1:1234", 4 * GB);
  RMApp app1 = MockRMAppSubmitter.submitWithMemory(2048, rm);
  // kick the scheduling, 2 GB given to AM1, remaining 2GB on nm1
  nm1.nodeHeartbeat(true);
  RMAppAttempt attempt1 = app1.getCurrentAppAttempt();
  MockAM am1 = rm.sendAMLaunched(attempt1.getAppAttemptId());
  am1.registerAppAttempt();
  SchedulerNodeReport report_nm1 =
      rm.getResourceScheduler().getNodeReport(nm1.getNodeId());
  // check node report, 2 GB used and 2 GB available
  Assert.assertEquals(2 * GB, report_nm1.getUsedResource().getMemorySize());
  Assert.assertEquals(2 * GB, report_nm1.getAvailableResource().getMemorySize());
  // add request for containers
  am1.addRequests(new String[] { "127.0.0.1", "127.0.0.2" }, 2 * GB, 1, 1);
  AllocateResponse alloc1Response = am1.schedule(); // send the request
  // kick the scheduler, 2 GB given to AM1, resource remaining 0
  nm1.nodeHeartbeat(true);
  while (alloc1Response.getAllocatedContainers().size() < 1) {
    LOG.info("Waiting for containers to be created for app 1...");
    Thread.sleep(1000);
    alloc1Response = am1.schedule();
  }
  List<Container> allocated1 = alloc1Response.getAllocatedContainers();
  Assert.assertEquals(1, allocated1.size());
  Assert.assertEquals(2 * GB, allocated1.get(0).getResource().getMemorySize());
  Assert.assertEquals(nm1.getNodeId(), allocated1.get(0).getNodeId());
  report_nm1 = rm.getResourceScheduler().getNodeReport(nm1.getNodeId());
  // check node report, 4 GB used and 0 GB available
  Assert.assertEquals(0, report_nm1.getAvailableResource().getMemorySize());
  Assert.assertEquals(4 * GB, report_nm1.getUsedResource().getMemorySize());
  // check container is assigned with 2 GB.
  Container c1 = allocated1.get(0);
  Assert.assertEquals(2 * GB, c1.getResource().getMemorySize());
  // update node resource to 2 GB, so resource is over-consumed.
  Map<NodeId, ResourceOption> nodeResourceMap =
      new HashMap<NodeId, ResourceOption>();
  nodeResourceMap.put(nm1.getNodeId(),
      ResourceOption.newInstance(Resource.newInstance(2 * GB, 1), -1));
  UpdateNodeResourceRequest request =
      UpdateNodeResourceRequest.newInstance(nodeResourceMap);
  rm.getAdminService().updateNodeResource(request);
  waitCount = 0;
  while (waitCount++ != 20) {
    report_nm1 = rm.getResourceScheduler().getNodeReport(nm1.getNodeId());
    if (null != report_nm1 &&
        report_nm1.getAvailableResource().getMemorySize() != 0) {
      break;
    }
    LOG.info("Waiting for RMNodeResourceUpdateEvent to be handled... Tried "
        + waitCount + " times already..");
    Thread.sleep(1000);
  }
  // Now, the used resource is still 4 GB, and available resource is minus
  // value.
  report_nm1 = rm.getResourceScheduler().getNodeReport(nm1.getNodeId());
  Assert.assertEquals(4 * GB, report_nm1.getUsedResource().getMemorySize());
  Assert.assertEquals(-2 * GB, report_nm1.getAvailableResource().getMemorySize());
  // Check container can complete successfully in case of resource
  // over-commitment.
  ContainerStatus containerStatus =
      BuilderUtils.newContainerStatus(c1.getId(), ContainerState.COMPLETE,
          "", 0, c1.getResource());
  nm1.containerStatus(containerStatus);
  waitCount = 0;
  while (attempt1.getJustFinishedContainers().size() < 1 && waitCount++ != 20) {
    LOG.info("Waiting for containers to be finished for app 1... Tried "
        + waitCount + " times already..");
    Thread.sleep(100);
  }
  Assert.assertEquals(1, attempt1.getJustFinishedContainers().size());
  Assert.assertEquals(1, am1.schedule().getCompletedContainersStatuses()
      .size());
  report_nm1 = rm.getResourceScheduler().getNodeReport(nm1.getNodeId());
  Assert.assertEquals(2 * GB, report_nm1.getUsedResource().getMemorySize());
  // As container return 2 GB back, the available resource becomes 0 again.
  Assert.assertEquals(0 * GB, report_nm1.getAvailableResource().getMemorySize());
  rm.stop();
}