zookeeper分布式锁实现秒杀案例(jfinal框架)

zookeeper分布式锁实现秒杀案例(jfinal框架)_第1张图片

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 exceptionList = new ArrayList();
 
    /**
     * 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 subNodes = zk.getChildren(ROOT_LOCK, false);
            // 取出所有lockName的锁
            List lockObjects = new ArrayList();
            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("

抢购成功!

");     } }   /**  * 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!

转载于:https://my.oschina.net/u/3985214/blog/2250902

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