zookeeper分布式锁实现秒杀案例(jfinal框架)

发布时间:2018-08-22作者:laosun阅读(681)

zookeeper分布式锁实现秒杀案例(jfinal框架)

    ZooKeeper是一个分布式的,开放源码的分布式应用程序协调服务,是Google的Chubby一个开源的实现,是Hadoop和Hbase的重要组件。它是一个为分布式应用提供一致性服务的软件,提供的功能包括:配置维护、域名服务、分布式同步、组服务等。


    ZooKeeper的架构通过冗余服务实现高可用性。因此,如果第一次无应答,客户端就可以询问另一台ZooKeeper主机。ZooKeeper节点将它们的数据存储于一个分层的命名空间,非常类似于一个文件系统或一个前缀树结构。客户端可以在节点读写,从而以这种方式拥有一个共享的配置服务。更新是全序的。


    基于ZooKeeper分布式锁的流程

    在zookeeper指定节点(locks)下创建临时顺序节点node_n

    获取locks下所有子节点children

    对子节点按节点自增序号从小到大排序

    判断本节点是不是第一个子节点,若是,则获取锁;若不是,则监听比该节点小的那个节点的删除事件

    若监听事件生效,则回到第二步重新进行判断,直到获取到锁

    具体实现

    下面就具体使用java和zookeeper实现分布式锁,操作zookeeper使用的是apache提供的zookeeper的包。


    通过实现Watch接口,实现process(WatchedEvent event)方法来实施监控,使CountDownLatch来完成监控,在等待锁的时候使用CountDownLatch来计数,等到后进行countDown,停止等待,继续运行。

    以下整体流程基本与上述描述流程一致,只是在监听的时候使用的是CountDownLatch来监听前一个节点。


    下边来看简单的实现源码,不用在乎代码的质量,这里只是简单地做个演示!!!


    分布式锁:

    package com.demo.utils;
    import org.apache.zookeeper.*;
    import org.apache.zookeeper.data.Stat;
    
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.List;
    import java.util.concurrent.CountDownLatch;
    import java.util.concurrent.TimeUnit;
    import java.util.concurrent.locks.Condition;
    import java.util.concurrent.locks.Lock;
    
    public class DistributedLock implements Lock, Watcher {
        private ZooKeeper zk = null;
        // 根节点
        private String ROOT_LOCK = "/locks";
        // 竞争的资源
        private String lockName;
        // 等待的前一个锁
        private String WAIT_LOCK;
        // 当前锁
        public String CURRENT_LOCK;
        // 计数器
        private CountDownLatch countDownLatch;
        private int sessionTimeout = 30000;
        private List<Exception> exceptionList = new ArrayList<Exception>();
    
        /**
         * 配置分布式锁
         * @param config 连接的url
         * @param lockName 竞争资源
         */
        public DistributedLock(String config, String lockName) {
            this.lockName = lockName;
            try {
                // 连接zookeeper
                zk = new ZooKeeper(config, sessionTimeout, this);
                Stat stat = zk.exists(ROOT_LOCK, false);
                if (stat == null) {
                    // 如果根节点不存在,则创建根节点
                    zk.create(ROOT_LOCK, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
                }
            } catch (IOException e) {
    //            e.printStackTrace();
            } catch (InterruptedException e) {
    //            e.printStackTrace();
            } catch (KeeperException e) {
    //            e.printStackTrace();
            }
        }
    
        // 节点监视器
        public void process(WatchedEvent event) {
            if (this.countDownLatch != null) {
                this.countDownLatch.countDown();
            }
        }
    
        public void lock() {
            if (exceptionList.size() > 0) {
                throw new LockException(exceptionList.get(0));
            }
            try {
                if (this.tryLock()) {
    //                System.out.println(Thread.currentThread().getName() + " " + lockName + "获得了锁");
                    return;
                } else {
                    // 等待锁
                    waitForLock(WAIT_LOCK, sessionTimeout);
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (KeeperException e) {
                e.printStackTrace();
            }
        }
    
        public boolean tryLock() {
            try {
                String splitStr = "_lock_";
                if (lockName.contains(splitStr)) {
                    throw new LockException("锁名有误");
                }
                // 创建临时有序节点
                CURRENT_LOCK = zk.create(ROOT_LOCK + "/" + lockName + splitStr, new byte[0],
                        ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
    //            System.out.println(CURRENT_LOCK + " 已经创建");
                // 取所有子节点
                List<String> subNodes = zk.getChildren(ROOT_LOCK, false);
                // 取出所有lockName的锁
                List<String> lockObjects = new ArrayList<String>();
                for (String node : subNodes) {
                    String _node = node.split(splitStr)[0];
                    if (_node.equals(lockName)) {
                        lockObjects.add(node);
                    }
                }
                Collections.sort(lockObjects);
    //            System.out.println(Thread.currentThread().getName() + " 的锁是 " + CURRENT_LOCK);
                // 若当前节点为最小节点,则获取锁成功
                if (CURRENT_LOCK.equals(ROOT_LOCK + "/" + lockObjects.get(0))) {
                    return true;
                }
    
                // 若不是最小节点,则找到自己的前一个节点
                String prevNode = CURRENT_LOCK.substring(CURRENT_LOCK.lastIndexOf("/") + 1);
                WAIT_LOCK = lockObjects.get(Collections.binarySearch(lockObjects, prevNode) - 1);
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (KeeperException e) {
                e.printStackTrace();
            }
            return false;
        }
    
        public boolean tryLock(long timeout, TimeUnit unit) {
            try {
                if (this.tryLock()) {
                    return true;
                }
                return waitForLock(WAIT_LOCK, timeout);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return false;
        }
    
        // 等待锁
        private boolean waitForLock(String prev, long waitTime) throws KeeperException, InterruptedException {
            Stat stat = zk.exists(ROOT_LOCK + "/" + prev, true);
    
            if (stat != null) {
    //            System.out.println(Thread.currentThread().getName() + "等待锁 " + ROOT_LOCK + "/" + prev);
                this.countDownLatch = new CountDownLatch(1);
                // 计数等待,若等到前一个节点消失,则precess中进行countDown,停止等待,获取锁
                this.countDownLatch.await(waitTime, TimeUnit.MILLISECONDS);
                this.countDownLatch = null;
    //            System.out.println(Thread.currentThread().getName() + " 等到了锁");
            }
            return true;
        }
    
        public void unlock() {
            try {
                System.out.println("释放锁 " + CURRENT_LOCK);
                zk.delete(CURRENT_LOCK, -1);
                CURRENT_LOCK = null;
                zk.close();
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (KeeperException e) {
                e.printStackTrace();
            }
        }
    
        public Condition newCondition() {
            return null;
        }
    
        public void lockInterruptibly() throws InterruptedException {
            this.lock();
        }
    
    
        public class LockException extends RuntimeException {
            private static final long serialVersionUID = 1L;
            public LockException(String e){
                super(e);
            }
            public LockException(Exception e){
                super(e);
            }
        }
    }

    入口类:

    package com.demo.index;
    
    import com.demo.utils.DistributedLock;
    import com.jfinal.core.Controller;
    import com.jfinal.plugin.activerecord.Db;
    import com.jfinal.plugin.activerecord.Record;
    
    /**
     * 秒杀/zookeeper 分布式锁
     * 
     * @author sun
     */
    public class SecKillForZookeeperController extends Controller {
    	
    	public static int goodsTotalNum = 100;
    
    	public void index() {
    		//每一次新的请求都会模拟抢购100件商品,所以先恢复商品的数量,这个可以不要,也可以手动去更新数据库
    		Db.update("update t_goods set num = ? where id = 1", goodsTotalNum);
    		
    		Record goods = Db.findFirst("select * from t_goods where id = 1");
    		Integer num = 0;
    		if(goods!=null){
    			num = goods.getInt("num");
    		}
    		
    		SecKillZookeeper sk = new SecKillZookeeper(num);
    		// 模拟120个人抢购。 模拟120人分别在不同的服务器进行发起请求
    		for (int i = 1; i <= 120; i++) {
    			new Thread(sk, i + " 号人").start();
    		}
    		
    		renderHtml("<center><h2>抢购成功!</h2></center>");
    	}
    }
    
    /**
     * 这里我们只是简单演示实现方式,至于事务等其他的都不添加了。
     * 
     * @author sun
     */
    class SecKillZookeeper implements Runnable {
    	
    	private int num = 0;
    	
    	public SecKillZookeeper(int num) {
    		this.num = num;
    	}
    	
    	@Override
    	public void run() {
    		DistributedLock lock = null;
    		try {
    			lock = new DistributedLock("127.0.0.1:2181", "test1");
    			lock.lock();
    			if (num > 0) {
    				sale(lock);
    				return ;
    			}
    		} finally {
    			if (lock != null) {
    				lock.unlock();
    			}
    		}
    		System.err.println(Thread.currentThread().getName() + " 太悲剧了,没抢到商品...");
    	}
    	
    	private void sale(DistributedLock lock) {
    		if(num>0){
    			Db.update("update t_goods set num=num-1 where id = 1");
    			num--;
    			System.out.println(Thread.currentThread().getName()+" 获取锁:"+lock.CURRENT_LOCK+" 抢到了第"+(SecKillForZookeeperController.goodsTotalNum - num)+" 件商品;");
    		}
    	}
    }

    打印结果:

    39 号人 获取锁:/locks/test1_lock_0000001385 抢到了第1 件商品;
    释放锁 /locks/test1_lock_0000001385
    35 号人 获取锁:/locks/test1_lock_0000001386 抢到了第2 件商品;
    释放锁 /locks/test1_lock_0000001386
    25 号人 获取锁:/locks/test1_lock_0000001387 抢到了第3 件商品;
    释放锁 /locks/test1_lock_0000001387
    42 号人 获取锁:/locks/test1_lock_0000001388 抢到了第4 件商品;
    释放锁 /locks/test1_lock_0000001388
    19 号人 获取锁:/locks/test1_lock_0000001389 抢到了第5 件商品;
    释放锁 /locks/test1_lock_0000001389
    38 号人 获取锁:/locks/test1_lock_0000001390 抢到了第6 件商品;
    释放锁 /locks/test1_lock_0000001390
    22 号人 获取锁:/locks/test1_lock_0000001391 抢到了第7 件商品;
    释放锁 /locks/test1_lock_0000001391
    18 号人 获取锁:/locks/test1_lock_0000001392 抢到了第8 件商品;
    释放锁 /locks/test1_lock_0000001392
    27 号人 获取锁:/locks/test1_lock_0000001393 抢到了第9 件商品;
    释放锁 /locks/test1_lock_0000001393
    28 号人 获取锁:/locks/test1_lock_0000001394 抢到了第10 件商品;
    释放锁 /locks/test1_lock_0000001394
    2 号人 获取锁:/locks/test1_lock_0000001395 抢到了第11 件商品;
    释放锁 /locks/test1_lock_0000001395
    14 号人 获取锁:/locks/test1_lock_0000001396 抢到了第12 件商品;
    释放锁 /locks/test1_lock_0000001396
    20 号人 获取锁:/locks/test1_lock_0000001397 抢到了第13 件商品;
    释放锁 /locks/test1_lock_0000001397
    11 号人 获取锁:/locks/test1_lock_0000001398 抢到了第14 件商品;
    释放锁 /locks/test1_lock_0000001398
    6 号人 获取锁:/locks/test1_lock_0000001399 抢到了第15 件商品;
    释放锁 /locks/test1_lock_0000001399
    7 号人 获取锁:/locks/test1_lock_0000001400 抢到了第16 件商品;
    释放锁 /locks/test1_lock_0000001400
    29 号人 获取锁:/locks/test1_lock_0000001401 抢到了第17 件商品;
    释放锁 /locks/test1_lock_0000001401
    3 号人 获取锁:/locks/test1_lock_0000001402 抢到了第18 件商品;
    释放锁 /locks/test1_lock_0000001402
    8 号人 获取锁:/locks/test1_lock_0000001403 抢到了第19 件商品;
    释放锁 /locks/test1_lock_0000001403
    32 号人 获取锁:/locks/test1_lock_0000001404 抢到了第20 件商品;
    释放锁 /locks/test1_lock_0000001404
    33 号人 获取锁:/locks/test1_lock_0000001405 抢到了第21 件商品;
    释放锁 /locks/test1_lock_0000001405
    23 号人 获取锁:/locks/test1_lock_0000001406 抢到了第22 件商品;
    释放锁 /locks/test1_lock_0000001406
    12 号人 获取锁:/locks/test1_lock_0000001407 抢到了第23 件商品;
    释放锁 /locks/test1_lock_0000001407
    15 号人 获取锁:/locks/test1_lock_0000001408 抢到了第24 件商品;
    释放锁 /locks/test1_lock_0000001408
    13 号人 获取锁:/locks/test1_lock_0000001409 抢到了第25 件商品;
    释放锁 /locks/test1_lock_0000001409
    34 号人 获取锁:/locks/test1_lock_0000001410 抢到了第26 件商品;
    释放锁 /locks/test1_lock_0000001410
    41 号人 获取锁:/locks/test1_lock_0000001411 抢到了第27 件商品;
    释放锁 /locks/test1_lock_0000001411
    37 号人 获取锁:/locks/test1_lock_0000001412 抢到了第28 件商品;
    释放锁 /locks/test1_lock_0000001412
    1 号人 获取锁:/locks/test1_lock_0000001413 抢到了第29 件商品;
    释放锁 /locks/test1_lock_0000001413
    52 号人 获取锁:/locks/test1_lock_0000001414 抢到了第30 件商品;
    释放锁 /locks/test1_lock_0000001414
    56 号人 获取锁:/locks/test1_lock_0000001415 抢到了第31 件商品;
    释放锁 /locks/test1_lock_0000001415
    26 号人 获取锁:/locks/test1_lock_0000001416 抢到了第32 件商品;
    释放锁 /locks/test1_lock_0000001416
    17 号人 获取锁:/locks/test1_lock_0000001417 抢到了第33 件商品;
    释放锁 /locks/test1_lock_0000001417
    40 号人 获取锁:/locks/test1_lock_0000001418 抢到了第34 件商品;
    释放锁 /locks/test1_lock_0000001418
    4 号人 获取锁:/locks/test1_lock_0000001419 抢到了第35 件商品;
    释放锁 /locks/test1_lock_0000001419
    46 号人 获取锁:/locks/test1_lock_0000001420 抢到了第36 件商品;
    释放锁 /locks/test1_lock_0000001420
    5 号人 获取锁:/locks/test1_lock_0000001421 抢到了第37 件商品;
    释放锁 /locks/test1_lock_0000001421
    54 号人 获取锁:/locks/test1_lock_0000001422 抢到了第38 件商品;
    释放锁 /locks/test1_lock_0000001422
    24 号人 获取锁:/locks/test1_lock_0000001423 抢到了第39 件商品;
    释放锁 /locks/test1_lock_0000001423
    48 号人 获取锁:/locks/test1_lock_0000001424 抢到了第40 件商品;
    释放锁 /locks/test1_lock_0000001424
    50 号人 获取锁:/locks/test1_lock_0000001425 抢到了第41 件商品;
    释放锁 /locks/test1_lock_0000001425
    21 号人 获取锁:/locks/test1_lock_0000001426 抢到了第42 件商品;
    释放锁 /locks/test1_lock_0000001426
    49 号人 获取锁:/locks/test1_lock_0000001427 抢到了第43 件商品;
    释放锁 /locks/test1_lock_0000001427
    36 号人 获取锁:/locks/test1_lock_0000001428 抢到了第44 件商品;
    释放锁 /locks/test1_lock_0000001428
    43 号人 获取锁:/locks/test1_lock_0000001429 抢到了第45 件商品;
    释放锁 /locks/test1_lock_0000001429
    44 号人 获取锁:/locks/test1_lock_0000001430 抢到了第46 件商品;
    释放锁 /locks/test1_lock_0000001430
    30 号人 获取锁:/locks/test1_lock_0000001431 抢到了第47 件商品;
    释放锁 /locks/test1_lock_0000001431
    47 号人 获取锁:/locks/test1_lock_0000001432 抢到了第48 件商品;
    释放锁 /locks/test1_lock_0000001432
    10 号人 获取锁:/locks/test1_lock_0000001433 抢到了第49 件商品;
    释放锁 /locks/test1_lock_0000001433
    9 号人 获取锁:/locks/test1_lock_0000001434 抢到了第50 件商品;
    释放锁 /locks/test1_lock_0000001434
    51 号人 获取锁:/locks/test1_lock_0000001435 抢到了第51 件商品;
    释放锁 /locks/test1_lock_0000001435
    31 号人 获取锁:/locks/test1_lock_0000001436 抢到了第52 件商品;
    释放锁 /locks/test1_lock_0000001436
    16 号人 获取锁:/locks/test1_lock_0000001437 抢到了第53 件商品;
    释放锁 /locks/test1_lock_0000001437
    45 号人 获取锁:/locks/test1_lock_0000001438 抢到了第54 件商品;
    释放锁 /locks/test1_lock_0000001438
    55 号人 获取锁:/locks/test1_lock_0000001439 抢到了第55 件商品;
    释放锁 /locks/test1_lock_0000001439
    53 号人 获取锁:/locks/test1_lock_0000001440 抢到了第56 件商品;
    释放锁 /locks/test1_lock_0000001440
    61 号人 获取锁:/locks/test1_lock_0000001441 抢到了第57 件商品;
    释放锁 /locks/test1_lock_0000001441
    59 号人 获取锁:/locks/test1_lock_0000001442 抢到了第58 件商品;
    释放锁 /locks/test1_lock_0000001442
    58 号人 获取锁:/locks/test1_lock_0000001443 抢到了第59 件商品;
    释放锁 /locks/test1_lock_0000001443
    57 号人 获取锁:/locks/test1_lock_0000001444 抢到了第60 件商品;
    释放锁 /locks/test1_lock_0000001444
    60 号人 获取锁:/locks/test1_lock_0000001445 抢到了第61 件商品;
    释放锁 /locks/test1_lock_0000001445
    92 号人 获取锁:/locks/test1_lock_0000001446 抢到了第62 件商品;
    释放锁 /locks/test1_lock_0000001446
    95 号人 获取锁:/locks/test1_lock_0000001447 抢到了第63 件商品;
    释放锁 /locks/test1_lock_0000001447
    94 号人 获取锁:/locks/test1_lock_0000001448 抢到了第64 件商品;
    释放锁 /locks/test1_lock_0000001448
    96 号人 获取锁:/locks/test1_lock_0000001449 抢到了第65 件商品;
    释放锁 /locks/test1_lock_0000001449
    98 号人 获取锁:/locks/test1_lock_0000001450 抢到了第66 件商品;
    释放锁 /locks/test1_lock_0000001450
    100 号人 获取锁:/locks/test1_lock_0000001451 抢到了第67 件商品;
    释放锁 /locks/test1_lock_0000001451
    101 号人 获取锁:/locks/test1_lock_0000001452 抢到了第68 件商品;
    释放锁 /locks/test1_lock_0000001452
    102 号人 获取锁:/locks/test1_lock_0000001453 抢到了第69 件商品;
    释放锁 /locks/test1_lock_0000001453
    104 号人 获取锁:/locks/test1_lock_0000001454 抢到了第70 件商品;
    释放锁 /locks/test1_lock_0000001454
    117 号人 获取锁:/locks/test1_lock_0000001455 抢到了第71 件商品;
    释放锁 /locks/test1_lock_0000001455
    116 号人 获取锁:/locks/test1_lock_0000001456 抢到了第72 件商品;
    释放锁 /locks/test1_lock_0000001456
    113 号人 获取锁:/locks/test1_lock_0000001457 抢到了第73 件商品;
    释放锁 /locks/test1_lock_0000001457
    119 号人 获取锁:/locks/test1_lock_0000001458 抢到了第74 件商品;
    释放锁 /locks/test1_lock_0000001458
    120 号人 获取锁:/locks/test1_lock_0000001459 抢到了第75 件商品;
    释放锁 /locks/test1_lock_0000001459
    111 号人 获取锁:/locks/test1_lock_0000001460 抢到了第76 件商品;
    释放锁 /locks/test1_lock_0000001460
    115 号人 获取锁:/locks/test1_lock_0000001461 抢到了第77 件商品;
    释放锁 /locks/test1_lock_0000001461
    107 号人 获取锁:/locks/test1_lock_0000001462 抢到了第78 件商品;
    释放锁 /locks/test1_lock_0000001462
    114 号人 获取锁:/locks/test1_lock_0000001463 抢到了第79 件商品;
    释放锁 /locks/test1_lock_0000001463
    109 号人 获取锁:/locks/test1_lock_0000001464 抢到了第80 件商品;
    释放锁 /locks/test1_lock_0000001464
    63 号人 获取锁:/locks/test1_lock_0000001465 抢到了第81 件商品;
    释放锁 /locks/test1_lock_0000001465
    62 号人 获取锁:/locks/test1_lock_0000001466 抢到了第82 件商品;
    释放锁 /locks/test1_lock_0000001466
    88 号人 获取锁:/locks/test1_lock_0000001467 抢到了第83 件商品;
    释放锁 /locks/test1_lock_0000001467
    81 号人 获取锁:/locks/test1_lock_0000001468 抢到了第84 件商品;
    释放锁 /locks/test1_lock_0000001468
    82 号人 获取锁:/locks/test1_lock_0000001469 抢到了第85 件商品;
    释放锁 /locks/test1_lock_0000001469
    87 号人 获取锁:/locks/test1_lock_0000001470 抢到了第86 件商品;
    释放锁 /locks/test1_lock_0000001470
    64 号人 获取锁:/locks/test1_lock_0000001471 抢到了第87 件商品;
    释放锁 /locks/test1_lock_0000001471
    84 号人 获取锁:/locks/test1_lock_0000001472 抢到了第88 件商品;
    释放锁 /locks/test1_lock_0000001472
    68 号人 获取锁:/locks/test1_lock_0000001473 抢到了第89 件商品;
    释放锁 /locks/test1_lock_0000001473
    67 号人 获取锁:/locks/test1_lock_0000001474 抢到了第90 件商品;
    释放锁 /locks/test1_lock_0000001474
    99 号人 获取锁:/locks/test1_lock_0000001475 抢到了第91 件商品;
    释放锁 /locks/test1_lock_0000001475
    78 号人 获取锁:/locks/test1_lock_0000001476 抢到了第92 件商品;
    释放锁 /locks/test1_lock_0000001476
    73 号人 获取锁:/locks/test1_lock_0000001477 抢到了第93 件商品;
    释放锁 /locks/test1_lock_0000001477
    71 号人 获取锁:/locks/test1_lock_0000001478 抢到了第94 件商品;
    释放锁 /locks/test1_lock_0000001478
    83 号人 获取锁:/locks/test1_lock_0000001479 抢到了第95 件商品;
    释放锁 /locks/test1_lock_0000001479
    91 号人 获取锁:/locks/test1_lock_0000001480 抢到了第96 件商品;
    释放锁 /locks/test1_lock_0000001480
    90 号人 获取锁:/locks/test1_lock_0000001481 抢到了第97 件商品;
    释放锁 /locks/test1_lock_0000001481
    65 号人 获取锁:/locks/test1_lock_0000001482 抢到了第98 件商品;
    释放锁 /locks/test1_lock_0000001482
    77 号人 获取锁:/locks/test1_lock_0000001483 抢到了第99 件商品;
    释放锁 /locks/test1_lock_0000001483
    76 号人 获取锁:/locks/test1_lock_0000001484 抢到了第100 件商品;
    释放锁 /locks/test1_lock_0000001484
    释放锁 /locks/test1_lock_0000001485
    75 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001486
    69 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001487
    89 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001488
    105 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001489
    85 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001490
    74 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001491
    66 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001492
    112 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001493
    释放锁 /locks/test1_lock_0000001494
    释放锁 /locks/test1_lock_0000001495
    70 号人 太悲剧了,没抢到商品...
    108 号人 太悲剧了,没抢到商品...
    79 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001496
    释放锁 /locks/test1_lock_0000001497
    93 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001498
    106 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001499
    103 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001500
    释放锁 /locks/test1_lock_0000001501
    72 号人 太悲剧了,没抢到商品...
    80 号人 太悲剧了,没抢到商品...
    118 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001502
    86 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001503
    97 号人 太悲剧了,没抢到商品...
    释放锁 /locks/test1_lock_0000001504
    110 号人 太悲剧了,没抢到商品...


    总体来说,如果了解到整个实现流程,使用zookeeper实现分布式锁并不是很困难,不过这也只是一个简单的实现,与前面实现Redis实现相比,本实现的稳定性更强,这是因为zookeeper的特性所致,在外界看来,zookeeper集群中每一个节点都是一致的。


    t_goods表结构:

    CREATE TABLE `d_sunjs_test`.`t_goods`  (
      `id` int(11) NOT NULL AUTO_INCREMENT,
      `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
      `num` int(11) NULL DEFAULT NULL,
      `version` int(11) NULL DEFAULT 1 COMMENT '乐观锁',
      PRIMARY KEY (`id`) USING BTREE
    ) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;


    测试的时候记得启动zookeeper服务!


    文章转载自:https://www.cnblogs.com/liuyang0/p/6800538.html

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