helix-core/src/test/java/org/apache/helix/monitoring/TestClusterStatusMonitorLifecycle.java - helix - Git at Google

 package org.apache.helix.monitoring;

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  */

 import java.lang.management.ManagementFactory;
 import java.util.Date;
 import java.util.HashSet;
 import java.util.Set;
 import javax.management.ObjectInstance;
 import javax.management.ObjectName;
 import javax.management.Query;
 import javax.management.QueryExp;

 import org.apache.helix.HelixDataAccessor;
 import org.apache.helix.TestHelper;
 import org.apache.helix.common.ZkTestBase;
 import org.apache.helix.integration.manager.ClusterDistributedController;
 import org.apache.helix.integration.manager.MockParticipantManager;
 import org.apache.helix.model.IdealState;
 import org.apache.helix.tools.ClusterSetup;
 import org.apache.helix.tools.ClusterVerifiers.BestPossibleExternalViewVerifier;
 import org.apache.helix.tools.ClusterVerifiers.ZkHelixClusterVerifier;
 import org.testng.Assert;
 import org.testng.annotations.AfterClass;
 import org.testng.annotations.BeforeClass;
 import org.testng.annotations.Test;

 public class TestClusterStatusMonitorLifecycle extends ZkTestBase {
   MockParticipantManager[] _participants;
   ClusterDistributedController[] _controllers;
   String _controllerClusterName;
   String _clusterNamePrefix;
   String _firstClusterName;
   Set<String> _clusters = new HashSet<>();

   final int n = 5;
   final int clusterNb = 10;

   @BeforeClass
   public void beforeClass() throws Exception {
     String className = TestHelper.getTestClassName();
     _clusterNamePrefix = className;

     System.out
         .println("START " + _clusterNamePrefix + " at " + new Date(System.currentTimeMillis()));

     // setup 10 clusters
     for (int i = 0; i < clusterNb; i++) {
       String clusterName = _clusterNamePrefix + "0_" + i;
       String participantName = "localhost" + i;
       String resourceName = "TestDB" + i;
       TestHelper.setupCluster(clusterName, ZK_ADDR, 12918, // participant port
           participantName, // participant name prefix
           resourceName, // resource name prefix
           1, // resources
           8, // partitions per resource
           n, // number of nodes
           3, // replicas
           "MasterSlave", true); // do rebalance

       _clusters.add(clusterName);
     }

     // setup controller cluster
     _controllerClusterName = "CONTROLLER_" + _clusterNamePrefix;
     TestHelper.setupCluster(_controllerClusterName, ZK_ADDR, // controller
         0, // port
         "controller", // participant name prefix
         _clusterNamePrefix, // resource name prefix
         1, // resources
         clusterNb, // partitions per resource
         n, // number of nodes
         3, // replicas
         "LeaderStandby", true); // do rebalance

     // start distributed cluster controllers
     _controllers = new ClusterDistributedController[n + n];
     for (int i = 0; i < n; i++) {
       _controllers[i] =
           new ClusterDistributedController(ZK_ADDR, _controllerClusterName, "controller_" + i);
       _controllers[i].syncStart();
     }

     ZkHelixClusterVerifier controllerClusterVerifier =
         new BestPossibleExternalViewVerifier.Builder(_controllerClusterName).setZkClient(_gZkClient)
             .setWaitTillVerify(TestHelper.DEFAULT_REBALANCE_PROCESSING_WAIT_TIME)
             .build();

     Assert.assertTrue(controllerClusterVerifier.verifyByPolling(),
         "Controller cluster NOT in ideal state");

     // start first cluster
     _participants = new MockParticipantManager[n];
     _firstClusterName = _clusterNamePrefix + "0_0";
     for (int i = 0; i < n; i++) {
       String instanceName = "localhost0_" + (12918 + i);
       _participants[i] = new MockParticipantManager(ZK_ADDR, _firstClusterName, instanceName);
       _participants[i].syncStart();
     }

     ZkHelixClusterVerifier firstClusterVerifier =
         new BestPossibleExternalViewVerifier.Builder(_firstClusterName).setZkClient(_gZkClient)
             .setWaitTillVerify(TestHelper.DEFAULT_REBALANCE_PROCESSING_WAIT_TIME)
             .build();
     Assert.assertTrue(firstClusterVerifier.verifyByPolling(), "first cluster NOT in ideal state");

     // add more controllers to controller cluster
     ClusterSetup setupTool = new ClusterSetup(ZK_ADDR);
     for (int i = 0; i < n; i++) {
       String controller = "controller_" + (n + i);
       setupTool.addInstanceToCluster(_controllerClusterName, controller);
     }
     setupTool.rebalanceStorageCluster(_controllerClusterName, _clusterNamePrefix + "0", 6);
     for (int i = n; i < 2 * n; i++) {
       _controllers[i] =
           new ClusterDistributedController(ZK_ADDR, _controllerClusterName, "controller_" + i);
       _controllers[i].syncStart();
     }

     // verify controller cluster
     Assert.assertTrue(controllerClusterVerifier.verifyByPolling(),
         "Controller cluster NOT in ideal state");

     // verify first cluster
     Assert.assertTrue(firstClusterVerifier.verifyByPolling(), "first cluster NOT in ideal state");
     // verify all the rest clusters
     for (int i = 1; i < clusterNb; i++) {
       ZkHelixClusterVerifier clusterVerifier =
           new BestPossibleExternalViewVerifier.Builder(_clusterNamePrefix + "0_" + i)
               .setZkClient(_gZkClient)
               .setWaitTillVerify(TestHelper.DEFAULT_REBALANCE_PROCESSING_WAIT_TIME)
               .build();
       Assert.assertTrue(clusterVerifier.verifyByPolling(), "Cluster NOT in ideal state.");
     }
   }

   @AfterClass
   public void afterClass() throws Exception {
     System.out.println("Cleaning up...");
     for (int i = 0; i < 2 * n; i++) {
       if (_controllers[i] != null) {
         _controllers[i].syncStop();
       }
     }
     for (MockParticipantManager participant : _participants) {
       if (participant != null) {
         participant.syncStop();
       }
     }
     cleanupControllers();
     deleteCluster(_controllerClusterName);

     for (String cluster : _clusters) {
       TestHelper.dropCluster(cluster, _gZkClient);
     }

     System.out.println("END " + _clusterNamePrefix + " at " + new Date(System.currentTimeMillis()));
   }

   private void cleanupControllers() {
     for (ClusterDistributedController controller : _controllers) {
       controller.syncStop();
     }
   }

   @Test
   public void testClusterStatusMonitorLifecycle() throws Exception {
     // Filter other unrelated clusters' metrics
     final QueryExp exp1 =
         Query.match(Query.attr("SensorName"), Query.value("*" + _clusterNamePrefix + "*"));
     final Set<ObjectInstance> mbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
         .queryMBeans(new ObjectName("ClusterStatus:*"), exp1));

     _participants[0].disconnect();

     // 1 participant goes away
     // No change in instance/resource mbean
     // Unregister 1 per-instance resource mbean and message queue mbean
     final int previousMBeanCount = mbeans.size();
     Assert.assertTrue(TestHelper.verify(() -> {
       Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
           .queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
       mbeans.clear();
       mbeans.addAll(newMbeans);
       return newMbeans.size() == (previousMBeanCount - 2);
     }, TestHelper.WAIT_DURATION));

     HelixDataAccessor accessor = _participants[n - 1].getHelixDataAccessor();
     String firstControllerName =
         accessor.getProperty(accessor.keyBuilder().controllerLeader()).getId();

     ClusterDistributedController firstController = null;
     for (ClusterDistributedController controller : _controllers) {
       if (controller.getInstanceName().equals(firstControllerName)) {
         firstController = controller;
       }
     }
     assert firstController != null;
     firstController.disconnect();

     ZkHelixClusterVerifier controllerClusterVerifier =
         new BestPossibleExternalViewVerifier.Builder(_controllerClusterName).setZkClient(_gZkClient)
             .setWaitTillVerify(TestHelper.DEFAULT_REBALANCE_PROCESSING_WAIT_TIME)
             .build();
     Assert.assertTrue(controllerClusterVerifier.verifyByPolling(),
         "Controller cluster was not converged");

     // 1 controller goes away
     // 1 message queue mbean, 1 PerInstanceResource mbean, and one event mbean
     final int previousMBeanCount2 = mbeans.size();
     Assert.assertTrue(TestHelper.verify(() -> {
       Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
           .queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
       mbeans.clear();
       mbeans.addAll(newMbeans);
       return newMbeans.size() == (previousMBeanCount2 - 3);
     }, TestHelper.WAIT_DURATION));

     String instanceName = "localhost0_" + (12918);
     _participants[0] = new MockParticipantManager(ZK_ADDR, _firstClusterName, instanceName);
     _participants[0].syncStart();

     // 1 participant comes back
     // No change in instance/resource mbean
     // Register 1 per-instance resource mbean and 1 message queue mbean
     final int previousMBeanCount3 = mbeans.size();
     Assert.assertTrue(TestHelper.verify(() -> {
       Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
           .queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
       mbeans.clear();
       mbeans.addAll(newMbeans);
       return newMbeans.size() == (previousMBeanCount3 + 2);
     }, TestHelper.WAIT_DURATION));

     // Add a resource
     // Register 1 resource mbean
     // Register 5 per-instance resource mbean
     ClusterSetup setupTool = new ClusterSetup(ZK_ADDR);
     IdealState idealState = accessor.getProperty(accessor.keyBuilder().idealStates("TestDB00"));

     setupTool.addResourceToCluster(_firstClusterName, "TestDB1", idealState.getNumPartitions(),
         "MasterSlave");
     setupTool.rebalanceResource(_firstClusterName, "TestDB1",
         Integer.parseInt(idealState.getReplicas()));

     // Add one resource, PerInstanceResource mbeans and 1 resource monitor
     final int previousMBeanCount4 = mbeans.size();
     Assert.assertTrue(TestHelper.verify(() -> {
       Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
           .queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
       mbeans.clear();
       mbeans.addAll(newMbeans);
       return newMbeans.size() == (previousMBeanCount4 + _participants.length + 1);
     }, TestHelper.WAIT_DURATION));

     // Remove a resource
     // No change in instance/resource mbean
     // Unregister 5 per-instance resource mbean
     setupTool.dropResourceFromCluster(_firstClusterName, "TestDB1");

     final int previousMBeanCount5 = mbeans.size();
     Assert.assertTrue(TestHelper.verify(() -> {
       Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
           .queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
       mbeans.clear();
       mbeans.addAll(newMbeans);
       return newMbeans.size() == (previousMBeanCount5 - (_participants.length + 1));
     }, TestHelper.WAIT_DURATION));

     // Cleanup controllers then MBeans should all be removed.
     cleanupControllers();
     // Check if any MBeans leftover.
     // Note that MessageQueueStatus is not bound with controller only. So it will still exist.
     final QueryExp exp2 = Query
         .and(Query.not(Query.match(Query.attr("SensorName"), Query.value("MessageQueueStatus.*"))),
             exp1);

     boolean result = TestHelper.verify(() -> ManagementFactory.getPlatformMBeanServer()
         .queryMBeans(new ObjectName("ClusterStatus:*"), exp2).isEmpty(), TestHelper.WAIT_DURATION);
     Assert.assertTrue(result, "Remaining MBeans: " + ManagementFactory.getPlatformMBeanServer()
         .queryMBeans(new ObjectName("ClusterStatus:*"), exp2).toString());
   }
 }
	package org.apache.helix.monitoring;

	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/

	import java.lang.management.ManagementFactory;
	import java.util.Date;
	import java.util.HashSet;
	import java.util.Set;
	import javax.management.ObjectInstance;
	import javax.management.ObjectName;
	import javax.management.Query;
	import javax.management.QueryExp;

	import org.apache.helix.HelixDataAccessor;
	import org.apache.helix.TestHelper;
	import org.apache.helix.common.ZkTestBase;
	import org.apache.helix.integration.manager.ClusterDistributedController;
	import org.apache.helix.integration.manager.MockParticipantManager;
	import org.apache.helix.model.IdealState;
	import org.apache.helix.tools.ClusterSetup;
	import org.apache.helix.tools.ClusterVerifiers.BestPossibleExternalViewVerifier;
	import org.apache.helix.tools.ClusterVerifiers.ZkHelixClusterVerifier;
	import org.testng.Assert;
	import org.testng.annotations.AfterClass;
	import org.testng.annotations.BeforeClass;
	import org.testng.annotations.Test;

	public class TestClusterStatusMonitorLifecycle extends ZkTestBase {
	MockParticipantManager[] _participants;
	ClusterDistributedController[] _controllers;
	String _controllerClusterName;
	String _clusterNamePrefix;
	String _firstClusterName;
	Set<String> _clusters = new HashSet<>();

	final int n = 5;
	final int clusterNb = 10;

	@BeforeClass
	public void beforeClass() throws Exception {
	String className = TestHelper.getTestClassName();
	_clusterNamePrefix = className;

	System.out
	.println("START " + _clusterNamePrefix + " at " + new Date(System.currentTimeMillis()));

	// setup 10 clusters
	for (int i = 0; i < clusterNb; i++) {
	String clusterName = _clusterNamePrefix + "0_" + i;
	String participantName = "localhost" + i;
	String resourceName = "TestDB" + i;
	TestHelper.setupCluster(clusterName, ZK_ADDR, 12918, // participant port
	participantName, // participant name prefix
	resourceName, // resource name prefix
	1, // resources
	8, // partitions per resource
	n, // number of nodes
	3, // replicas
	"MasterSlave", true); // do rebalance

	_clusters.add(clusterName);
	}

	// setup controller cluster
	_controllerClusterName = "CONTROLLER_" + _clusterNamePrefix;
	TestHelper.setupCluster(_controllerClusterName, ZK_ADDR, // controller
	0, // port
	"controller", // participant name prefix
	_clusterNamePrefix, // resource name prefix
	1, // resources
	clusterNb, // partitions per resource
	n, // number of nodes
	3, // replicas
	"LeaderStandby", true); // do rebalance

	// start distributed cluster controllers
	_controllers = new ClusterDistributedController[n + n];
	for (int i = 0; i < n; i++) {
	_controllers[i] =
	new ClusterDistributedController(ZK_ADDR, _controllerClusterName, "controller_" + i);
	_controllers[i].syncStart();
	}

	ZkHelixClusterVerifier controllerClusterVerifier =
	new BestPossibleExternalViewVerifier.Builder(_controllerClusterName).setZkClient(_gZkClient)
	.setWaitTillVerify(TestHelper.DEFAULT_REBALANCE_PROCESSING_WAIT_TIME)
	.build();

	Assert.assertTrue(controllerClusterVerifier.verifyByPolling(),
	"Controller cluster NOT in ideal state");

	// start first cluster
	_participants = new MockParticipantManager[n];
	_firstClusterName = _clusterNamePrefix + "0_0";
	for (int i = 0; i < n; i++) {
	String instanceName = "localhost0_" + (12918 + i);
	_participants[i] = new MockParticipantManager(ZK_ADDR, _firstClusterName, instanceName);
	_participants[i].syncStart();
	}

	ZkHelixClusterVerifier firstClusterVerifier =
	new BestPossibleExternalViewVerifier.Builder(_firstClusterName).setZkClient(_gZkClient)
	.setWaitTillVerify(TestHelper.DEFAULT_REBALANCE_PROCESSING_WAIT_TIME)
	.build();
	Assert.assertTrue(firstClusterVerifier.verifyByPolling(), "first cluster NOT in ideal state");

	// add more controllers to controller cluster
	ClusterSetup setupTool = new ClusterSetup(ZK_ADDR);
	for (int i = 0; i < n; i++) {
	String controller = "controller_" + (n + i);
	setupTool.addInstanceToCluster(_controllerClusterName, controller);
	}
	setupTool.rebalanceStorageCluster(_controllerClusterName, _clusterNamePrefix + "0", 6);
	for (int i = n; i < 2 * n; i++) {
	_controllers[i] =
	new ClusterDistributedController(ZK_ADDR, _controllerClusterName, "controller_" + i);
	_controllers[i].syncStart();
	}

	// verify controller cluster
	Assert.assertTrue(controllerClusterVerifier.verifyByPolling(),
	"Controller cluster NOT in ideal state");

	// verify first cluster
	Assert.assertTrue(firstClusterVerifier.verifyByPolling(), "first cluster NOT in ideal state");
	// verify all the rest clusters
	for (int i = 1; i < clusterNb; i++) {
	ZkHelixClusterVerifier clusterVerifier =
	new BestPossibleExternalViewVerifier.Builder(_clusterNamePrefix + "0_" + i)
	.setZkClient(_gZkClient)
	.setWaitTillVerify(TestHelper.DEFAULT_REBALANCE_PROCESSING_WAIT_TIME)
	.build();
	Assert.assertTrue(clusterVerifier.verifyByPolling(), "Cluster NOT in ideal state.");
	}
	}

	@AfterClass
	public void afterClass() throws Exception {
	System.out.println("Cleaning up...");
	for (int i = 0; i < 2 * n; i++) {
	if (_controllers[i] != null) {
	_controllers[i].syncStop();
	}
	}
	for (MockParticipantManager participant : _participants) {
	if (participant != null) {
	participant.syncStop();
	}
	}
	cleanupControllers();
	deleteCluster(_controllerClusterName);

	for (String cluster : _clusters) {
	TestHelper.dropCluster(cluster, _gZkClient);
	}

	System.out.println("END " + _clusterNamePrefix + " at " + new Date(System.currentTimeMillis()));
	}

	private void cleanupControllers() {
	for (ClusterDistributedController controller : _controllers) {
	controller.syncStop();
	}
	}

	@Test
	public void testClusterStatusMonitorLifecycle() throws Exception {
	// Filter other unrelated clusters' metrics
	final QueryExp exp1 =
	Query.match(Query.attr("SensorName"), Query.value("" + _clusterNamePrefix + ""));
	final Set<ObjectInstance> mbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
	.queryMBeans(new ObjectName("ClusterStatus:*"), exp1));

	_participants[0].disconnect();

	// 1 participant goes away
	// No change in instance/resource mbean
	// Unregister 1 per-instance resource mbean and message queue mbean
	final int previousMBeanCount = mbeans.size();
	Assert.assertTrue(TestHelper.verify(() -> {
	Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
	.queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
	mbeans.clear();
	mbeans.addAll(newMbeans);
	return newMbeans.size() == (previousMBeanCount - 2);
	}, TestHelper.WAIT_DURATION));

	HelixDataAccessor accessor = _participants[n - 1].getHelixDataAccessor();
	String firstControllerName =
	accessor.getProperty(accessor.keyBuilder().controllerLeader()).getId();

	ClusterDistributedController firstController = null;
	for (ClusterDistributedController controller : _controllers) {
	if (controller.getInstanceName().equals(firstControllerName)) {
	firstController = controller;
	}
	}
	assert firstController != null;
	firstController.disconnect();

	ZkHelixClusterVerifier controllerClusterVerifier =
	new BestPossibleExternalViewVerifier.Builder(_controllerClusterName).setZkClient(_gZkClient)
	.setWaitTillVerify(TestHelper.DEFAULT_REBALANCE_PROCESSING_WAIT_TIME)
	.build();
	Assert.assertTrue(controllerClusterVerifier.verifyByPolling(),
	"Controller cluster was not converged");

	// 1 controller goes away
	// 1 message queue mbean, 1 PerInstanceResource mbean, and one event mbean
	final int previousMBeanCount2 = mbeans.size();
	Assert.assertTrue(TestHelper.verify(() -> {
	Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
	.queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
	mbeans.clear();
	mbeans.addAll(newMbeans);
	return newMbeans.size() == (previousMBeanCount2 - 3);
	}, TestHelper.WAIT_DURATION));

	String instanceName = "localhost0_" + (12918);
	_participants[0] = new MockParticipantManager(ZK_ADDR, _firstClusterName, instanceName);
	_participants[0].syncStart();

	// 1 participant comes back
	// No change in instance/resource mbean
	// Register 1 per-instance resource mbean and 1 message queue mbean
	final int previousMBeanCount3 = mbeans.size();
	Assert.assertTrue(TestHelper.verify(() -> {
	Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
	.queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
	mbeans.clear();
	mbeans.addAll(newMbeans);
	return newMbeans.size() == (previousMBeanCount3 + 2);
	}, TestHelper.WAIT_DURATION));

	// Add a resource
	// Register 1 resource mbean
	// Register 5 per-instance resource mbean
	ClusterSetup setupTool = new ClusterSetup(ZK_ADDR);
	IdealState idealState = accessor.getProperty(accessor.keyBuilder().idealStates("TestDB00"));

	setupTool.addResourceToCluster(_firstClusterName, "TestDB1", idealState.getNumPartitions(),
	"MasterSlave");
	setupTool.rebalanceResource(_firstClusterName, "TestDB1",
	Integer.parseInt(idealState.getReplicas()));

	// Add one resource, PerInstanceResource mbeans and 1 resource monitor
	final int previousMBeanCount4 = mbeans.size();
	Assert.assertTrue(TestHelper.verify(() -> {
	Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
	.queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
	mbeans.clear();
	mbeans.addAll(newMbeans);
	return newMbeans.size() == (previousMBeanCount4 + _participants.length + 1);
	}, TestHelper.WAIT_DURATION));

	// Remove a resource
	// No change in instance/resource mbean
	// Unregister 5 per-instance resource mbean
	setupTool.dropResourceFromCluster(_firstClusterName, "TestDB1");

	final int previousMBeanCount5 = mbeans.size();
	Assert.assertTrue(TestHelper.verify(() -> {
	Set<ObjectInstance> newMbeans = new HashSet<>(ManagementFactory.getPlatformMBeanServer()
	.queryMBeans(new ObjectName("ClusterStatus:*"), exp1));
	mbeans.clear();
	mbeans.addAll(newMbeans);
	return newMbeans.size() == (previousMBeanCount5 - (_participants.length + 1));
	}, TestHelper.WAIT_DURATION));

	// Cleanup controllers then MBeans should all be removed.
	cleanupControllers();
	// Check if any MBeans leftover.
	// Note that MessageQueueStatus is not bound with controller only. So it will still exist.
	final QueryExp exp2 = Query
	.and(Query.not(Query.match(Query.attr("SensorName"), Query.value("MessageQueueStatus.*"))),
	exp1);

	boolean result = TestHelper.verify(() -> ManagementFactory.getPlatformMBeanServer()
	.queryMBeans(new ObjectName("ClusterStatus:*"), exp2).isEmpty(), TestHelper.WAIT_DURATION);
	Assert.assertTrue(result, "Remaining MBeans: " + ManagementFactory.getPlatformMBeanServer()
	.queryMBeans(new ObjectName("ClusterStatus:*"), exp2).toString());
	}
	}