zookeeper-server/src/test/java/org/apache/zookeeper/server/CreateContainerTest.java - zookeeper - Git at Google

 /*
  * 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.
  */

 package org.apache.zookeeper.server;

 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assertions.fail;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executors;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
 import org.apache.zookeeper.AsyncCallback;
 import org.apache.zookeeper.CreateMode;
 import org.apache.zookeeper.DeleteContainerRequest;
 import org.apache.zookeeper.KeeperException;
 import org.apache.zookeeper.Op;
 import org.apache.zookeeper.ZooDefs;
 import org.apache.zookeeper.ZooKeeper;
 import org.apache.zookeeper.data.Stat;
 import org.apache.zookeeper.test.ClientBase;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.Timeout;

 public class CreateContainerTest extends ClientBase {

     private ZooKeeper zk;
     private Semaphore completedContainerDeletions;

     @BeforeEach
     @Override
     public void setUp() throws Exception {
         super.setUp();
         zk = createClient();

         completedContainerDeletions = new Semaphore(0);
         ZKDatabase testDatabase = new ZKDatabase(serverFactory.zkServer.getZKDatabase().snapLog) {
             @Override
             public void addCommittedProposal(Request request) {
                 super.addCommittedProposal(request);
                 if (request.type == ZooDefs.OpCode.deleteContainer) {
                     completedContainerDeletions.release();
                 }
             }
         };
         serverFactory.zkServer.setZKDatabase(testDatabase);
     }

     @AfterEach
     @Override
     public void tearDown() throws Exception {
         super.tearDown();
         zk.close();
     }

     @Test
     @Timeout(value = 30)
     public void testCreate() throws KeeperException, InterruptedException {
         createNoStatVerifyResult("/foo");
         createNoStatVerifyResult("/foo/child");
     }

     @Test
     @Timeout(value = 30)
     public void testCreateWithStat() throws KeeperException, InterruptedException {
         Stat stat = createWithStatVerifyResult("/foo");
         Stat childStat = createWithStatVerifyResult("/foo/child");
         // Don't expect to get the same stats for different creates.
         assertNotEquals(stat, childStat);
     }

     @SuppressWarnings("ConstantConditions")
     @Test
     @Timeout(value = 30)
     public void testCreateWithNullStat() throws KeeperException, InterruptedException {
         final String name = "/foo";
         assertNull(zk.exists(name, false));

         Stat stat = null;
         // If a null Stat object is passed the create should still
         // succeed, but no Stat info will be returned.
         zk.create(name, name.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER, stat);
         assertNull(stat);
         assertNotNull(zk.exists(name, false));
     }

     @Test
     @Timeout(value = 30)
     public void testSimpleDeletion() throws KeeperException, InterruptedException {
         zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         zk.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
         zk.delete("/foo/bar", -1);  // should cause "/foo" to get deleted when checkContainers() is called

         ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100);
         containerManager.checkContainers();

         assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
         assertNull(zk.exists("/foo", false), "Container should have been deleted");
     }

     @Test
     @Timeout(value = 30)
     public void testMultiWithContainerSimple() throws KeeperException, InterruptedException {
         Op createContainer = Op.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         zk.multi(Collections.singletonList(createContainer));

         DataTree dataTree = serverFactory.getZooKeeperServer().getZKDatabase().getDataTree();
         assertEquals(dataTree.getContainers().size(), 1);
     }

     @Test
     @Timeout(value = 30)
     public void testMultiWithContainer() throws KeeperException, InterruptedException {
         Op createContainer = Op.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         Op createChild = Op.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
         zk.multi(Arrays.asList(createContainer, createChild));

         DataTree dataTree = serverFactory.getZooKeeperServer().getZKDatabase().getDataTree();
         assertEquals(dataTree.getContainers().size(), 1);

         zk.delete("/foo/bar", -1);  // should cause "/foo" to get deleted when checkContainers() is called

         ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100);
         containerManager.checkContainers();

         assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
         assertNull(zk.exists("/foo", false), "Container should have been deleted");

         createContainer = Op.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         createChild = Op.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
         Op deleteChild = Op.delete("/foo/bar", -1);
         zk.multi(Arrays.asList(createContainer, createChild, deleteChild));

         containerManager.checkContainers();

         assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
         assertNull(zk.exists("/foo", false), "Container should have been deleted");
     }

     @Test
     @Timeout(value = 30)
     public void testSimpleDeletionAsync() throws KeeperException, InterruptedException {
         final CountDownLatch latch = new CountDownLatch(1);
         AsyncCallback.Create2Callback cb = (rc, path, ctx, name, stat) -> {
             assertEquals(ctx, "context");
             latch.countDown();
         };
         zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER, cb, "context");
         assertTrue(latch.await(5, TimeUnit.SECONDS));
         zk.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
         zk.delete("/foo/bar", -1);  // should cause "/foo" to get deleted when checkContainers() is called

         ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100);
         containerManager.checkContainers();

         assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
         assertNull(zk.exists("/foo", false), "Container should have been deleted");
     }

     @Test
     @Timeout(value = 30)
     public void testCascadingDeletion() throws KeeperException, InterruptedException {
         zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         zk.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         zk.create("/foo/bar/one", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
         zk.delete("/foo/bar/one", -1);  // should cause "/foo/bar" and "/foo" to get deleted when checkContainers() is called

         ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100);
         containerManager.checkContainers();
         assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
         containerManager.checkContainers();
         assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));

         assertNull(zk.exists("/foo/bar", false), "Container should have been deleted");
         assertNull(zk.exists("/foo", false), "Container should have been deleted");
     }

     @Test
     @Timeout(value = 30)
     public void testFalseEmpty() throws KeeperException, InterruptedException {
         zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         zk.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);

         ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100) {
             @Override protected Collection<String> getCandidates() {
                 return Collections.singletonList("/foo");
             }
         };
         containerManager.checkContainers();

         assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
         assertNotNull(zk.exists("/foo", false), "Container should have not been deleted");
     }

     @Test
     @Timeout(value = 30)
     public void testMaxPerMinute() throws InterruptedException {
         final BlockingQueue<String> queue = new LinkedBlockingQueue<>();
         RequestProcessor processor = new RequestProcessor() {
             @Override
             public void processRequest(Request request) {
                 try {
                     queue.add(request.readRequestRecord(DeleteContainerRequest::new).getPath());
                 } catch (IOException e) {
                     fail(e);
                 }
             }

             @Override
             public void shutdown() {
             }
         };
         final ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), processor, 1, 2) {
             @Override
             protected long getMinIntervalMs() {
                 return 1000;
             }

             @Override
             protected Collection<String> getCandidates() {
                 return Arrays.asList("/one", "/two", "/three", "/four");
             }
         };
         Executors.newSingleThreadExecutor().submit(() -> {
             containerManager.checkContainers();
             return null;
         });
         assertEquals("/one", queue.poll(5, TimeUnit.SECONDS));
         assertEquals("/two", queue.poll(5, TimeUnit.SECONDS));
         assertEquals(0, queue.size());
         Thread.sleep(500);
         assertEquals(0, queue.size());
         assertEquals("/three", queue.poll(5, TimeUnit.SECONDS));
         assertEquals("/four", queue.poll(5, TimeUnit.SECONDS));
     }

     @Test
     @Timeout(value = 30)
     public void testMaxNeverUsedInterval() throws KeeperException, InterruptedException {
         zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         AtomicLong elapsed = new AtomicLong(0);
         AtomicInteger deletesQty = new AtomicInteger(0);
         ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100, 1000) {
             @Override
             protected void postDeleteRequest(Request request) throws RequestProcessor.RequestProcessorException {
                 deletesQty.incrementAndGet();
                 super.postDeleteRequest(request);
             }

             @Override
             protected long getElapsed(DataNode node) {
                 return elapsed.get();
             }
         };
         containerManager.checkContainers(); // elapsed time will appear to be 0 - container will not get deleted
         assertEquals(deletesQty.get(), 0);
         assertNotNull(zk.exists("/foo", false), "Container should not have been deleted");

         elapsed.set(10000);
         containerManager.checkContainers(); // elapsed time will appear to be 10000 - container should get deleted
         assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
         assertNull(zk.exists("/foo", false), "Container should have been deleted");
     }

     @Test
     @Timeout(value = 30)
     public void testZeroMaxNeverUsedInterval() throws KeeperException, InterruptedException {
         zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         AtomicInteger deletesQty = new AtomicInteger(0);
         ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100, 0) {
             @Override protected void postDeleteRequest(Request request) throws RequestProcessor.RequestProcessorException {
                 deletesQty.incrementAndGet();
                 super.postDeleteRequest(request);
             }

             @Override protected long getElapsed(DataNode node) {
                 return 10000;   // some number greater than 0
             }
         };
         containerManager.checkContainers(); // elapsed time will appear to be 0 - container will not get deleted
         assertEquals(deletesQty.get(), 0);
         assertNotNull(zk.exists("/foo", false), "Container should not have been deleted");
     }

     private void createNoStatVerifyResult(String newName) throws KeeperException, InterruptedException {
         assertNull(zk.exists(newName, false), "Node existed before created");
         zk.create(newName, newName.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
         assertNotNull(zk.exists(newName, false), "Node was not created as expected");
     }

     private Stat createWithStatVerifyResult(String newName) throws KeeperException, InterruptedException {
         assertNull(zk.exists(newName, false), "Node existed before created");
         Stat stat = new Stat();
         zk.create(newName, newName.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER, stat);
         validateCreateStat(stat, newName);

         Stat referenceStat = zk.exists(newName, false);
         assertNotNull(referenceStat, "Node was not created as expected");
         assertEquals(referenceStat, stat);

         return stat;
     }

     private void validateCreateStat(Stat stat, String name) {
         assertEquals(stat.getCzxid(), stat.getMzxid());
         assertEquals(stat.getCzxid(), stat.getPzxid());
         assertEquals(stat.getCtime(), stat.getMtime());
         assertEquals(0, stat.getCversion());
         assertEquals(0, stat.getVersion());
         assertEquals(0, stat.getAversion());
         assertEquals(0, stat.getEphemeralOwner());
         assertEquals(name.length(), stat.getDataLength());
         assertEquals(0, stat.getNumChildren());
     }

 }
	/*
	* 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.
	*/

	package org.apache.zookeeper.server;

	import static org.junit.jupiter.api.Assertions.assertEquals;
	import static org.junit.jupiter.api.Assertions.assertNotEquals;
	import static org.junit.jupiter.api.Assertions.assertNotNull;
	import static org.junit.jupiter.api.Assertions.assertNull;
	import static org.junit.jupiter.api.Assertions.assertTrue;
	import static org.junit.jupiter.api.Assertions.fail;
	import java.io.IOException;
	import java.util.Arrays;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.concurrent.BlockingQueue;
	import java.util.concurrent.CountDownLatch;
	import java.util.concurrent.Executors;
	import java.util.concurrent.LinkedBlockingQueue;
	import java.util.concurrent.Semaphore;
	import java.util.concurrent.TimeUnit;
	import java.util.concurrent.atomic.AtomicInteger;
	import java.util.concurrent.atomic.AtomicLong;
	import org.apache.zookeeper.AsyncCallback;
	import org.apache.zookeeper.CreateMode;
	import org.apache.zookeeper.DeleteContainerRequest;
	import org.apache.zookeeper.KeeperException;
	import org.apache.zookeeper.Op;
	import org.apache.zookeeper.ZooDefs;
	import org.apache.zookeeper.ZooKeeper;
	import org.apache.zookeeper.data.Stat;
	import org.apache.zookeeper.test.ClientBase;
	import org.junit.jupiter.api.AfterEach;
	import org.junit.jupiter.api.BeforeEach;
	import org.junit.jupiter.api.Test;
	import org.junit.jupiter.api.Timeout;

	public class CreateContainerTest extends ClientBase {

	private ZooKeeper zk;
	private Semaphore completedContainerDeletions;

	@BeforeEach
	@Override
	public void setUp() throws Exception {
	super.setUp();
	zk = createClient();

	completedContainerDeletions = new Semaphore(0);
	ZKDatabase testDatabase = new ZKDatabase(serverFactory.zkServer.getZKDatabase().snapLog) {
	@Override
	public void addCommittedProposal(Request request) {
	super.addCommittedProposal(request);
	if (request.type == ZooDefs.OpCode.deleteContainer) {
	completedContainerDeletions.release();
	}
	}
	};
	serverFactory.zkServer.setZKDatabase(testDatabase);
	}

	@AfterEach
	@Override
	public void tearDown() throws Exception {
	super.tearDown();
	zk.close();
	}

	@Test
	@Timeout(value = 30)
	public void testCreate() throws KeeperException, InterruptedException {
	createNoStatVerifyResult("/foo");
	createNoStatVerifyResult("/foo/child");
	}

	@Test
	@Timeout(value = 30)
	public void testCreateWithStat() throws KeeperException, InterruptedException {
	Stat stat = createWithStatVerifyResult("/foo");
	Stat childStat = createWithStatVerifyResult("/foo/child");
	// Don't expect to get the same stats for different creates.
	assertNotEquals(stat, childStat);
	}

	@SuppressWarnings("ConstantConditions")
	@Test
	@Timeout(value = 30)
	public void testCreateWithNullStat() throws KeeperException, InterruptedException {
	final String name = "/foo";
	assertNull(zk.exists(name, false));

	Stat stat = null;
	// If a null Stat object is passed the create should still
	// succeed, but no Stat info will be returned.
	zk.create(name, name.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER, stat);
	assertNull(stat);
	assertNotNull(zk.exists(name, false));
	}

	@Test
	@Timeout(value = 30)
	public void testSimpleDeletion() throws KeeperException, InterruptedException {
	zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	zk.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
	zk.delete("/foo/bar", -1); // should cause "/foo" to get deleted when checkContainers() is called

	ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100);
	containerManager.checkContainers();

	assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
	assertNull(zk.exists("/foo", false), "Container should have been deleted");
	}

	@Test
	@Timeout(value = 30)
	public void testMultiWithContainerSimple() throws KeeperException, InterruptedException {
	Op createContainer = Op.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	zk.multi(Collections.singletonList(createContainer));

	DataTree dataTree = serverFactory.getZooKeeperServer().getZKDatabase().getDataTree();
	assertEquals(dataTree.getContainers().size(), 1);
	}

	@Test
	@Timeout(value = 30)
	public void testMultiWithContainer() throws KeeperException, InterruptedException {
	Op createContainer = Op.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	Op createChild = Op.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
	zk.multi(Arrays.asList(createContainer, createChild));

	DataTree dataTree = serverFactory.getZooKeeperServer().getZKDatabase().getDataTree();
	assertEquals(dataTree.getContainers().size(), 1);

	zk.delete("/foo/bar", -1); // should cause "/foo" to get deleted when checkContainers() is called

	ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100);
	containerManager.checkContainers();

	assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
	assertNull(zk.exists("/foo", false), "Container should have been deleted");

	createContainer = Op.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	createChild = Op.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
	Op deleteChild = Op.delete("/foo/bar", -1);
	zk.multi(Arrays.asList(createContainer, createChild, deleteChild));

	containerManager.checkContainers();

	assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
	assertNull(zk.exists("/foo", false), "Container should have been deleted");
	}

	@Test
	@Timeout(value = 30)
	public void testSimpleDeletionAsync() throws KeeperException, InterruptedException {
	final CountDownLatch latch = new CountDownLatch(1);
	AsyncCallback.Create2Callback cb = (rc, path, ctx, name, stat) -> {
	assertEquals(ctx, "context");
	latch.countDown();
	};
	zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER, cb, "context");
	assertTrue(latch.await(5, TimeUnit.SECONDS));
	zk.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
	zk.delete("/foo/bar", -1); // should cause "/foo" to get deleted when checkContainers() is called

	ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100);
	containerManager.checkContainers();

	assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
	assertNull(zk.exists("/foo", false), "Container should have been deleted");
	}

	@Test
	@Timeout(value = 30)
	public void testCascadingDeletion() throws KeeperException, InterruptedException {
	zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	zk.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	zk.create("/foo/bar/one", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
	zk.delete("/foo/bar/one", -1); // should cause "/foo/bar" and "/foo" to get deleted when checkContainers() is called

	ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100);
	containerManager.checkContainers();
	assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
	containerManager.checkContainers();
	assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));

	assertNull(zk.exists("/foo/bar", false), "Container should have been deleted");
	assertNull(zk.exists("/foo", false), "Container should have been deleted");
	}

	@Test
	@Timeout(value = 30)
	public void testFalseEmpty() throws KeeperException, InterruptedException {
	zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	zk.create("/foo/bar", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);

	ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100) {
	@Override protected Collection<String> getCandidates() {
	return Collections.singletonList("/foo");
	}
	};
	containerManager.checkContainers();

	assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
	assertNotNull(zk.exists("/foo", false), "Container should have not been deleted");
	}

	@Test
	@Timeout(value = 30)
	public void testMaxPerMinute() throws InterruptedException {
	final BlockingQueue<String> queue = new LinkedBlockingQueue<>();
	RequestProcessor processor = new RequestProcessor() {
	@Override
	public void processRequest(Request request) {
	try {
	queue.add(request.readRequestRecord(DeleteContainerRequest::new).getPath());
	} catch (IOException e) {
	fail(e);
	}
	}

	@Override
	public void shutdown() {
	}
	};
	final ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), processor, 1, 2) {
	@Override
	protected long getMinIntervalMs() {
	return 1000;
	}

	@Override
	protected Collection<String> getCandidates() {
	return Arrays.asList("/one", "/two", "/three", "/four");
	}
	};
	Executors.newSingleThreadExecutor().submit(() -> {
	containerManager.checkContainers();
	return null;
	});
	assertEquals("/one", queue.poll(5, TimeUnit.SECONDS));
	assertEquals("/two", queue.poll(5, TimeUnit.SECONDS));
	assertEquals(0, queue.size());
	Thread.sleep(500);
	assertEquals(0, queue.size());
	assertEquals("/three", queue.poll(5, TimeUnit.SECONDS));
	assertEquals("/four", queue.poll(5, TimeUnit.SECONDS));
	}

	@Test
	@Timeout(value = 30)
	public void testMaxNeverUsedInterval() throws KeeperException, InterruptedException {
	zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	AtomicLong elapsed = new AtomicLong(0);
	AtomicInteger deletesQty = new AtomicInteger(0);
	ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100, 1000) {
	@Override
	protected void postDeleteRequest(Request request) throws RequestProcessor.RequestProcessorException {
	deletesQty.incrementAndGet();
	super.postDeleteRequest(request);
	}

	@Override
	protected long getElapsed(DataNode node) {
	return elapsed.get();
	}
	};
	containerManager.checkContainers(); // elapsed time will appear to be 0 - container will not get deleted
	assertEquals(deletesQty.get(), 0);
	assertNotNull(zk.exists("/foo", false), "Container should not have been deleted");

	elapsed.set(10000);
	containerManager.checkContainers(); // elapsed time will appear to be 10000 - container should get deleted
	assertTrue(completedContainerDeletions.tryAcquire(1, TimeUnit.SECONDS));
	assertNull(zk.exists("/foo", false), "Container should have been deleted");
	}

	@Test
	@Timeout(value = 30)
	public void testZeroMaxNeverUsedInterval() throws KeeperException, InterruptedException {
	zk.create("/foo", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	AtomicInteger deletesQty = new AtomicInteger(0);
	ContainerManager containerManager = new ContainerManager(serverFactory.getZooKeeperServer().getZKDatabase(), serverFactory.getZooKeeperServer().firstProcessor, 1, 100, 0) {
	@Override protected void postDeleteRequest(Request request) throws RequestProcessor.RequestProcessorException {
	deletesQty.incrementAndGet();
	super.postDeleteRequest(request);
	}

	@Override protected long getElapsed(DataNode node) {
	return 10000; // some number greater than 0
	}
	};
	containerManager.checkContainers(); // elapsed time will appear to be 0 - container will not get deleted
	assertEquals(deletesQty.get(), 0);
	assertNotNull(zk.exists("/foo", false), "Container should not have been deleted");
	}

	private void createNoStatVerifyResult(String newName) throws KeeperException, InterruptedException {
	assertNull(zk.exists(newName, false), "Node existed before created");
	zk.create(newName, newName.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER);
	assertNotNull(zk.exists(newName, false), "Node was not created as expected");
	}

	private Stat createWithStatVerifyResult(String newName) throws KeeperException, InterruptedException {
	assertNull(zk.exists(newName, false), "Node existed before created");
	Stat stat = new Stat();
	zk.create(newName, newName.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.CONTAINER, stat);
	validateCreateStat(stat, newName);

	Stat referenceStat = zk.exists(newName, false);
	assertNotNull(referenceStat, "Node was not created as expected");
	assertEquals(referenceStat, stat);

	return stat;
	}

	private void validateCreateStat(Stat stat, String name) {
	assertEquals(stat.getCzxid(), stat.getMzxid());
	assertEquals(stat.getCzxid(), stat.getPzxid());
	assertEquals(stat.getCtime(), stat.getMtime());
	assertEquals(0, stat.getCversion());
	assertEquals(0, stat.getVersion());
	assertEquals(0, stat.getAversion());
	assertEquals(0, stat.getEphemeralOwner());
	assertEquals(name.length(), stat.getDataLength());
	assertEquals(0, stat.getNumChildren());
	}

	}