Springboot + Redis 分布式锁

素颜马尾好姑娘i 2023-10-01 10:21 1阅读 0赞

### 一、版本与环境搭建： ###

服务器百度云（Centos7）、Redis（6.2.6）、Jdk（17.0.1）

详情如图（Redis单机部署）：  
![在这里插入图片描述][watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA54yq5oKf6YGT_size_20_color_FFFFFF_t_70_g_se_x_16]![在这里插入图片描述][7dd403073ddf4888bf8d7d9d67a07cd2.png]

<table> 
 <thead> 
  <tr> 
   <th>Centos</th> 
   <th>7.9</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>Redis</td> 
   <td>2.5.7</td> 
  </tr> 
  <tr> 
   <td>Redisson</td> 
   <td>3.16.6</td> 
  </tr> 
  <tr> 
   <td>Jdk</td> 
   <td>17.0.1</td> 
  </tr> 
  <tr> 
   <td>Springboot</td> 
   <td>2.5.7</td> 
  </tr> 
 </tbody> 
</table>

### 二、分布式锁：模拟秒杀扣减库存活动 ###

写在前面：Redis是单线程，I/O多路复用

**1.单机模式下简单设置：**

问题：如果最后多个请求同时到来，同时获取库存；则均进入扣减环节，最后库存为0 订单超额

解决：加入synchronized锁，包裹扣减代码，变为单线程执行

package com.demo.controller;
    
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.data.redis.core.StringRedisTemplate;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import javax.annotation.Resource;
    
    /**
     * Description: 减库存
     *
     * @Author: zhx & moon hongxu_1234@163.com
     * @Date: 2021-12-19 14:09
     * @version: V1.0.0
     */
    @RestController
    @RequestMapping("/reduce")
    @Slf4j
    public class IndexLearn {
        
    
        @Resource
        StringRedisTemplate stringRedisTemplate;
    
        /**
         * 获取库存
         * 库存为 1 如果3个请求同时获取，则在减库存时数据异常
         * 加入synchronized锁 则牺牲性能解决 单机 情况问题
         */
        @GetMapping("deductStock")
        public String deductStock(){
        
            //获取剩余库存
            int stock = Integer.parseInt(stringRedisTemplate.opsForValue().get("stock"));
            //如果有库存 则扣减
            if (stock>0){
        
                int realStock = stock - 1;
                stringRedisTemplate.opsForValue().set("stock",realStock + "");
                log.info("剩余库存:{}",realStock);
                return "success";
            }else{
        
                log.error("库存不足");
                return "error";
            }
        }
    }

**2.双机部署，两台服务，通过Nginx代理进行均衡配置**

问题：此时，synchronized锁无法保证两台机器之间的同步，可能两个机器同时获取同一个库存，则扣减后，库存值

减一，但是实际生成了两条订单，出现超卖情况  
![在这里插入图片描述][watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA54yq5oKf6YGT_size_20_color_FFFFFF_t_70_g_se_x_16 1]解决：在扣减前，通过Redis加锁，谁扣减库存谁加锁，扣减完成在释放

package com.demo.controller;
    
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.data.redis.core.StringRedisTemplate;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import javax.annotation.Resource;
    
    /**
     * Description: 减库存
     *
     * @Author: zhx & moon hongxu_1234@163.com
     * @Date: 2021-12-19 14:09
     * @version: V1.0.0
     */
    @RestController
    @RequestMapping("/reduce")
    @Slf4j
    public class IndexLearn {
        
    
        @Resource
        StringRedisTemplate stringRedisTemplate;
    
        /**
         * 获取库存
         * 1.获取库存前，通过Redis模拟锁操作，如key：product_0 value：pod_1
         *   则节点1在对产品0加锁，申请库存，进行扣减
         * 2.setIfAbsent 键值不存在时成功，存在时失败
         */
        @GetMapping("deductStock")
        public String deductStock(){
        
    
            String locKey = "product_0";
            String clientId = "pod_1";
    
            try {
        
                boolean result = stringRedisTemplate.opsForValue().setIfAbsent(locKey,clientId);
                //判断是否存在锁
                if (!result){
        
                    return "error";
                }
                //获取库存
                int stock = Integer.parseInt(stringRedisTemplate.opsForValue().get("stock"));
                //扣减
                if (stock>0){
        
                    int realStock = stock - 1;
                    stringRedisTemplate.opsForValue().set("stock",realStock + "");
                    log.info("剩余库存:{}",realStock);
                    return "success";
                }else{
        
                    log.error("库存不足");
                    return "error";
                }
            }finally {
        
                //删除锁
                stringRedisTemplate.delete(locKey);
            }
        }
    }

**三、问题来了：**

1.如果节点1加锁后，宕机，则锁无法释放，此时系统将死锁，无法进行秒杀：为锁设置超时时间

stringRedisTemplate.opsForValue().setIfAbsent(locKey,clientId,10, TimeUnit.SECONDS);

2.设置超时时间后，节点1服务器异常卡顿，锁超时，自动释放；节点2服务器获取锁，进行扣减，此时节点1执行完成，将锁释放 -----：加判断，只有自己可以释放自己的锁，引入雪花算法用于生成ID

if (clientId.equals(stringRedisTemplate.opsForValue().get(locKey))){
        
        stringRedisTemplate.delete(locKey);
    }

3.代码本身正常耗时超过超时时间，锁释放，引发异常：加锁后，起一个子线程去监督执行情况，每1/3超时周期检测一次，未执行完成则重置锁时间

**使用Redisson解决上述问题（支持续期和互斥，可重入）：**

Redisson续期机制：加锁成功，就会启动一个看门狗（源码没注释，大概看下吧）：

private <T> RFuture<Long> tryAcquireAsync(long waitTime, long leaseTime, TimeUnit unit, long threadId) {
        
        RFuture ttlRemainingFuture;
        if (leaseTime != -1L) {
        
            ttlRemainingFuture = this.tryLockInnerAsync(waitTime, leaseTime, unit, threadId, RedisCommands.EVAL_LONG);
        } else {
        
            ttlRemainingFuture = this.tryLockInnerAsync(waitTime, this.internalLockLeaseTime, TimeUnit.MILLISECONDS, threadId, RedisCommands.EVAL_LONG);
        }
    
        ttlRemainingFuture.onComplete((ttlRemaining, e) -> {
        
            if (e == null) {
        
                if (ttlRemaining == null) {
        
                    if (leaseTime != -1L) {
        
                        this.internalLockLeaseTime = unit.toMillis(leaseTime);
                    } else {
        
                        this.scheduleExpirationRenewal(threadId);
                    }
                }
    
            }
        });
        return ttlRemainingFuture;
    }
        
    protected void scheduleExpirationRenewal(long threadId) {
        
        ExpirationEntry entry = new ExpirationEntry();
        ExpirationEntry oldEntry = EXPIRATION_RENEWAL_MAP.putIfAbsent(getEntryName(), entry);
        if (oldEntry != null) {
        
            oldEntry.addThreadId(threadId);
        } else {
        
            entry.addThreadId(threadId);
            try {
        
                renewExpiration();
            } finally {
        
                if (Thread.currentThread().isInterrupted()) {
        
                    cancelExpirationRenewal(threadId);
                }
            }
        }
    }
    
    private void renewExpiration() {
        
        ExpirationEntry ee = EXPIRATION_RENEWAL_MAP.get(getEntryName());
        if (ee == null) {
        
            return;
        }
        
        Timeout task = commandExecutor.getConnectionManager().newTimeout(new TimerTask() {
        
            @Override
            public void run(Timeout timeout) throws Exception {
        
                ExpirationEntry ent = EXPIRATION_RENEWAL_MAP.get(getEntryName());
                if (ent == null) {
        
                    return;
                }
                Long threadId = ent.getFirstThreadId();
                if (threadId == null) {
        
                    return;
                }
                
                RFuture<Boolean> future = renewExpirationAsync(threadId);
                future.onComplete((res, e) -> {
        
                    if (e != null) {
        
                        log.error("Can't update lock " + getRawName() + " expiration", e);
                        EXPIRATION_RENEWAL_MAP.remove(getEntryName());
                        return;
                    }
                    
                    if (res) {
        
                        // reschedule itself
                        renewExpiration();
                    } else {
        
                        cancelExpirationRenewal(null);
                    }
                });
            }
        }, internalLockLeaseTime / 3, TimeUnit.MILLISECONDS);
        
        ee.setTimeout(task);
    }

扣减库存：

package com.demo.controller;
    
    import lombok.extern.slf4j.Slf4j;
    import org.redisson.Redisson;
    import org.redisson.api.RLock;
    import org.springframework.data.redis.core.StringRedisTemplate;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import javax.annotation.Resource;
    import java.util.concurrent.TimeUnit;
    
    /**
     * Description: 减库存
     *
     * @Author: zhx & moon hongxu_1234@163.com
     * @Date: 2021-12-19 14:09
     * @version: V1.0.0
     */
    @RestController
    @RequestMapping("/reduce")
    @Slf4j
    public class IndexLearn {
        
    
        @Resource
        StringRedisTemplate stringRedisTemplate;
    
    
        @Resource
        Redisson redisson;
    
        @GetMapping("deductStock")
        public String deductStock(){
        
            String locKey = "product_0";
            RLock rLock = redisson.getLock(locKey);
            try {
        
    
                /**
                 * 阻塞三十秒 每10秒检测线程状态 
                 * 如果线程未完成，则自动续期
                 */
                rLock.lock();
                int stock = Integer.parseInt(stringRedisTemplate.opsForValue().get("stock"));
                if (stock>0){
        
                    int realStock = stock - 1;
                    stringRedisTemplate.opsForValue().set("stock",realStock + "");
                    log.info("剩余库存:{}",realStock);
                    return "success";
                }else{
        
                    log.error("库存不足");
                    return "error";
                }
            }finally {
        
                rLock.unlock();
            }
        }
    }

Redis数据和Redisson初始化

package com.demo.config;
    
    import org.redisson.Redisson;
    import org.redisson.config.Config;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.DependsOn;
    import org.springframework.data.redis.core.StringRedisTemplate;
    import org.springframework.stereotype.Component;
    
    import javax.annotation.PostConstruct;
    import javax.annotation.Resource;
    
    /**
     * Description: 测试数据初始化
     *
     * @Author: zhx & moon hongxu_1234@163.com
     * @Date: 2021-12-19 14:15
     * @version: V1.0.0
     */
    @Component
    public class InitRedis {
        
    
        @Resource
        private StringRedisTemplate stringRedisTemplate;
    
    
        @PostConstruct
        public void init(){
        
            stringRedisTemplate.opsForValue().set("stock","1");
        }
    
    }

package com.demo.config;
    
    import org.redisson.Redisson;
    import org.redisson.config.Config;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.Bean;
    import org.springframework.stereotype.Component;
    
    /**
     * Description: 初始化Redisson
     *
     * @Author: zhx & moon hongxu_1234@163.com
     * @Date: 2021-12-20 17:26
     * @version: V1.0.0
     */
    @Component
    public class InitRedisson {
        
    
        @Value("${spring.redis.host}")
        private String redisIp;
    
        @Value("${spring.redis.port}")
        private int redisPort;
    
        @Value("${spring.redis.password}")
        private String password;
    
        private int dataBase = 1;
    
        @Bean
        public Redisson redisson(){
        
            /**
             * 单机模式启动
             */
            String redisUrl = "redis://" + redisIp + ":" + redisPort;
            Config config = new Config();
            config.useSingleServer().setAddress(redisUrl).setDatabase(dataBase).setPassword(password);
            return (Redisson) Redisson.create(config);
        }
    }

**四、利用Hutool实现雪花算法工具类**

String clientId = SnowFlakeUtil.getIdStr();

package com.demo.util;
    
    import cn.hutool.core.lang.Snowflake;
    import cn.hutool.core.net.NetUtil;
    import cn.hutool.core.util.IdUtil;
    import org.springframework.stereotype.Component;
    
    /**
     * Description: 雪花算法
     *
     * 64bit大小的整数
     * 1bit，保留，因为二进制中最高位是符号位，1表示负数，0表示正数 默认0
     * 41bit-毫秒级时间戳
     * 10bit-服务器设备id 5位 datacenterId 和5位 workerId
     * 12bit-序列号，同毫秒内产生的不同Id
     *
     * @Author: zhx & moon hongxu_1234@163.com
     * @Date: 2021-12-19 12:45
     * @version: V1.0.0
     */
    @Component
    public class SnowFlakeUtil {
        
    
        private long workerId = 0;
    
        private long datacenterId = 0;
    
        private Snowflake snowflake = IdUtil.createSnowflake(workerId,datacenterId);
    
        public SnowFlakeUtil(){
        
            workerId = NetUtil.ipv4ToLong(NetUtil.getLocalhostStr());
        }
    
        public synchronized long snowflakeId(){
        
            return snowflake.nextId();
        }
    
        public synchronized String snowflakeIdStr(){
        
            return snowflake.nextIdStr();
        }
    
        /**
         * 成员类，SnowFlakeUtil的实例对象的保存域
         */
        private static class IdGenHolder {
        
            private static final SnowFlakeUtil instance = new SnowFlakeUtil();
        }
    
        /**
         * 可直接调用
         */
        public static SnowFlakeUtil get() {
        
            return IdGenHolder.instance;
        }
    
        public static Long getId() {
        
            return SnowFlakeUtil.get().snowflakeId();
        }
    
        public static String getIdStr() {
        
            return SnowFlakeUtil.get().snowflakeIdStr();
        }
    }

**Pom文件**

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.5.7</version>
            <relativePath/>
        </parent>
        <groupId>com.demo</groupId>
        <artifactId>redis</artifactId>
        <version>1.0-SNAPSHOT</version>
    
        <properties>
            <maven.compiler.source>17</maven.compiler.source>
            <maven.compiler.target>17</maven.compiler.target>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-redis</artifactId>
            </dependency>
            <dependency>
                <groupId>org.redisson</groupId>
                <artifactId>redisson-spring-boot-starter</artifactId>
                <version>3.16.6</version>
            </dependency>
    
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
            </dependency>
    
            <dependency>
                <groupId>cn.hutool</groupId>
                <artifactId>hutool-all</artifactId>
                <version>5.4.2</version>
            </dependency>
    
        </dependencies>
    </project>

**配置文件**

server:
      port: 8899
    
    spring:
      application: hongxu_moon
      redis:
        # Redis数据库索引（默认为0）
        database: 0
        # Redis服务器地址
        host: 106.12.148.211
        # Redis服务器连接端口
        port: 6379
        # Redis服务器连接密码（默认为空）
        password: 123456
        timeout: 100
        pool:
          # 连接池最大连接数（使用负值表示没有限制）
          max-active: 8
          # 连接池最大阻塞等待时间（使用负值表示没有限制）
          max-wait: -1
          # 连接池中的最大空闲连接
          max-idle: 8
          # 连接池中的最小空闲连接
          min-idle: 0
          # 连接超时时间（毫秒）
          timeout: 100

**五、结果**

调用：http://127.0.0.1:8899/reduce/deductRedisson  
返回：

![在这里插入图片描述][6a2a70767db547f8b6be160b1297c708.png]

"C:\Program Files\Java\jdk-17.0.1\bin\java.exe" -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:50309,suspend=y,server=n -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -javaagent:C:\Users\Administrator\AppData\Local\JetBrains\IntelliJIdea2021.2\captureAgent\debugger-agent.jar -Dcom.sun.management.jmxremote -Dspring.jmx.enabled=true -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true -Dfile.encoding=UTF-8 -classpath "E:\IdeaProjects\redis\target\classes;D:\apache-maven-space\org\springframework\boot\spring-boot-starter-web\2.5.7\spring-boot-starter-web-2.5.7.jar;D:\apache-maven-space\org\springframework\boot\spring-boot-starter\2.5.7\spring-boot-starter-2.5.7.jar;D:\apache-maven-space\org\springframework\boot\spring-boot\2.5.7\spring-boot-2.5.7.jar;D:\apache-maven-space\org\springframework\boot\spring-boot-autoconfigure\2.5.7\spring-boot-autoconfigure-2.5.7.jar;D:\apache-maven-space\org\springframework\boot\spring-boot-starter-logging\2.5.7\spring-boot-starter-logging-2.5.7.jar;D:\apache-maven-space\ch\qos\logback\logback-classic\1.2.7\logback-classic-1.2.7.jar;D:\apache-maven-space\ch\qos\logback\logback-core\1.2.7\logback-core-1.2.7.jar;D:\apache-maven-space\org\apache\logging\log4j\log4j-to-slf4j\2.14.1\log4j-to-slf4j-2.14.1.jar;D:\apache-maven-space\org\apache\logging\log4j\log4j-api\2.14.1\log4j-api-2.14.1.jar;D:\apache-maven-space\org\slf4j\jul-to-slf4j\1.7.32\jul-to-slf4j-1.7.32.jar;D:\apache-maven-space\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;D:\apache-maven-space\org\springframework\spring-core\5.3.13\spring-core-5.3.13.jar;D:\apache-maven-space\org\springframework\spring-jcl\5.3.13\spring-jcl-5.3.13.jar;D:\apache-maven-space\org\yaml\snakeyaml\1.28\snakeyaml-1.28.jar;D:\apache-maven-space\org\springframework\boot\spring-boot-starter-json\2.5.7\spring-boot-starter-json-2.5.7.jar;D:\apache-maven-space\com\fasterxml\jackson\core\jackson-databind\2.12.5\jackson-databind-2.12.5.jar;D:\apache-maven-space\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.12.5\jackson-datatype-jdk8-2.12.5.jar;D:\apache-maven-space\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.12.5\jackson-datatype-jsr310-2.12.5.jar;D:\apache-maven-space\com\fasterxml\jackson\module\jackson-module-parameter-names\2.12.5\jackson-module-parameter-names-2.12.5.jar;D:\apache-maven-space\org\springframework\boot\spring-boot-starter-tomcat\2.5.7\spring-boot-starter-tomcat-2.5.7.jar;D:\apache-maven-space\org\apache\tomcat\embed\tomcat-embed-core\9.0.55\tomcat-embed-core-9.0.55.jar;D:\apache-maven-space\org\apache\tomcat\embed\tomcat-embed-el\9.0.55\tomcat-embed-el-9.0.55.jar;D:\apache-maven-space\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.55\tomcat-embed-websocket-9.0.55.jar;D:\apache-maven-space\org\springframework\spring-web\5.3.13\spring-web-5.3.13.jar;D:\apache-maven-space\org\springframework\spring-beans\5.3.13\spring-beans-5.3.13.jar;D:\apache-maven-space\org\springframework\spring-webmvc\5.3.13\spring-webmvc-5.3.13.jar;D:\apache-maven-space\org\springframework\spring-aop\5.3.13\spring-aop-5.3.13.jar;D:\apache-maven-space\org\springframework\spring-context\5.3.13\spring-context-5.3.13.jar;D:\apache-maven-space\org\springframework\spring-expression\5.3.13\spring-expression-5.3.13.jar;D:\apache-maven-space\org\springframework\boot\spring-boot-starter-data-redis\2.5.7\spring-boot-starter-data-redis-2.5.7.jar;D:\apache-maven-space\org\springframework\data\spring-data-redis\2.5.7\spring-data-redis-2.5.7.jar;D:\apache-maven-space\org\springframework\data\spring-data-keyvalue\2.5.7\spring-data-keyvalue-2.5.7.jar;D:\apache-maven-space\org\springframework\data\spring-data-commons\2.5.7\spring-data-commons-2.5.7.jar;D:\apache-maven-space\org\springframework\spring-tx\5.3.13\spring-tx-5.3.13.jar;D:\apache-maven-space\org\springframework\spring-oxm\5.3.13\spring-oxm-5.3.13.jar;D:\apache-maven-space\org\springframework\spring-context-support\5.3.13\spring-context-support-5.3.13.jar;D:\apache-maven-space\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar;D:\apache-maven-space\io\lettuce\lettuce-core\6.1.5.RELEASE\lettuce-core-6.1.5.RELEASE.jar;D:\apache-maven-space\io\netty\netty-common\4.1.70.Final\netty-common-4.1.70.Final.jar;D:\apache-maven-space\io\netty\netty-handler\4.1.70.Final\netty-handler-4.1.70.Final.jar;D:\apache-maven-space\io\netty\netty-transport\4.1.70.Final\netty-transport-4.1.70.Final.jar;D:\apache-maven-space\io\projectreactor\reactor-core\3.4.12\reactor-core-3.4.12.jar;D:\apache-maven-space\org\redisson\redisson-spring-boot-starter\3.16.6\redisson-spring-boot-starter-3.16.6.jar;D:\apache-maven-space\org\springframework\boot\spring-boot-starter-actuator\2.5.7\spring-boot-starter-actuator-2.5.7.jar;D:\apache-maven-space\org\springframework\boot\spring-boot-actuator-autoconfigure\2.5.7\spring-boot-actuator-autoconfigure-2.5.7.jar;D:\apache-maven-space\org\springframework\boot\spring-boot-actuator\2.5.7\spring-boot-actuator-2.5.7.jar;D:\apache-maven-space\io\micrometer\micrometer-core\1.7.6\micrometer-core-1.7.6.jar;D:\apache-maven-space\org\hdrhistogram\HdrHistogram\2.1.12\HdrHistogram-2.1.12.jar;D:\apache-maven-space\org\latencyutils\LatencyUtils\2.0.3\LatencyUtils-2.0.3.jar;D:\apache-maven-space\org\redisson\redisson\3.16.6\redisson-3.16.6.jar;D:\apache-maven-space\io\netty\netty-codec\4.1.70.Final\netty-codec-4.1.70.Final.jar;D:\apache-maven-space\io\netty\netty-buffer\4.1.70.Final\netty-buffer-4.1.70.Final.jar;D:\apache-maven-space\io\netty\netty-resolver\4.1.70.Final\netty-resolver-4.1.70.Final.jar;D:\apache-maven-space\io\netty\netty-resolver-dns\4.1.70.Final\netty-resolver-dns-4.1.70.Final.jar;D:\apache-maven-space\io\netty\netty-codec-dns\4.1.70.Final\netty-codec-dns-4.1.70.Final.jar;D:\apache-maven-space\javax\cache\cache-api\1.1.1\cache-api-1.1.1.jar;D:\apache-maven-space\org\reactivestreams\reactive-streams\1.0.3\reactive-streams-1.0.3.jar;D:\apache-maven-space\io\reactivex\rxjava3\rxjava\3.0.12\rxjava-3.0.12.jar;D:\apache-maven-space\org\jboss\marshalling\jboss-marshalling\2.0.11.Final\jboss-marshalling-2.0.11.Final.jar;D:\apache-maven-space\org\jboss\marshalling\jboss-marshalling-river\2.0.11.Final\jboss-marshalling-river-2.0.11.Final.jar;D:\apache-maven-space\com\fasterxml\jackson\core\jackson-annotations\2.12.5\jackson-annotations-2.12.5.jar;D:\apache-maven-space\com\fasterxml\jackson\dataformat\jackson-dataformat-yaml\2.12.5\jackson-dataformat-yaml-2.12.5.jar;D:\apache-maven-space\com\fasterxml\jackson\core\jackson-core\2.12.5\jackson-core-2.12.5.jar;D:\apache-maven-space\net\bytebuddy\byte-buddy\1.10.22\byte-buddy-1.10.22.jar;D:\apache-maven-space\org\jodd\jodd-bean\5.1.6\jodd-bean-5.1.6.jar;D:\apache-maven-space\org\jodd\jodd-core\5.1.6\jodd-core-5.1.6.jar;D:\apache-maven-space\org\redisson\redisson-spring-data-25\3.16.6\redisson-spring-data-25-3.16.6.jar;D:\apache-maven-space\org\projectlombok\lombok\1.18.22\lombok-1.18.22.jar;D:\apache-maven-space\cn\hutool\hutool-all\5.4.2\hutool-all-5.4.2.jar;D:\Program Files\JetBrains\IntelliJ IDEA 2020.2.3\lib\idea_rt.jar" com.demo.RedisApplication
    Java HotSpot(TM) 64-Bit Server VM warning: Options -Xverify:none and -noverify were deprecated in JDK 13 and will likely be removed in a future release.
    Connected to the target VM, address: '127.0.0.1:50309', transport: 'socket'
    Java HotSpot(TM) 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended
    
      .   ____          _            __ _ _
     /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
     \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
      '  |____| .__|_| |_|_| |_\__, | / / / /
     =========|_|==============|___/=/_/_/_/
     :: Spring Boot ::                (v2.5.7)
    
    2021-12-20 17:27:47.371  INFO 20436 --- [           main] com.demo.RedisApplication                : Starting RedisApplication using Java 17.0.1 on zhx_yue with PID 20436 (E:\IdeaProjects\redis\target\classes started by Administrator in E:\IdeaProjects\redis)
    2021-12-20 17:27:47.372  INFO 20436 --- [           main] com.demo.RedisApplication                : No active profile set, falling back to default profiles: default
    2021-12-20 17:27:47.780  INFO 20436 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Multiple Spring Data modules found, entering strict repository configuration mode!
    2021-12-20 17:27:47.781  INFO 20436 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data Redis repositories in DEFAULT mode.
    2021-12-20 17:27:47.792  INFO 20436 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 3 ms. Found 0 Redis repository interfaces.
    2021-12-20 17:27:48.007  INFO 20436 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8899 (http)
    2021-12-20 17:27:48.012  INFO 20436 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
    2021-12-20 17:27:48.012  INFO 20436 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.55]
    2021-12-20 17:27:48.053  INFO 20436 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    2021-12-20 17:27:48.054  INFO 20436 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 660 ms
    2021-12-20 17:27:51.063  INFO 20436 --- [           main] org.redisson.Version                     : Redisson 3.16.6
    2021-12-20 17:27:51.248  INFO 20436 --- [sson-netty-2-32] o.r.c.pool.PubSubConnectionPool          : 1 connections initialized for 106.12.148.211/106.12.148.211:6379
    2021-12-20 17:27:51.246  INFO 20436 --- [sson-netty-2-31] o.r.c.pool.MasterPubSubConnectionPool    : 1 connections initialized for 106.12.148.211/106.12.148.211:6379
    2021-12-20 17:27:51.278  INFO 20436 --- [isson-netty-2-3] o.r.c.pool.MasterConnectionPool          : 24 connections initialized for 106.12.148.211/106.12.148.211:6379
    2021-12-20 17:27:51.279  INFO 20436 --- [isson-netty-2-5] o.r.connection.pool.SlaveConnectionPool  : 24 connections initialized for 106.12.148.211/106.12.148.211:6379
    2021-12-20 17:27:52.260  INFO 20436 --- [           main] o.s.b.a.e.web.EndpointLinksResolver      : Exposing 1 endpoint(s) beneath base path '/actuator'
    2021-12-20 17:27:52.286  INFO 20436 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8899 (http) with context path ''
    2021-12-20 17:27:52.295  INFO 20436 --- [           main] com.demo.RedisApplication                : Started RedisApplication in 5.124 seconds (JVM running for 5.551)
    2021-12-20 17:27:52.599  INFO 20436 --- [6)-192.168.18.4] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
    2021-12-20 17:27:52.599  INFO 20436 --- [6)-192.168.18.4] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
    2021-12-20 17:27:52.600  INFO 20436 --- [6)-192.168.18.4] o.s.web.servlet.DispatcherServlet        : Completed initialization in 1 ms
    2021-12-20 17:29:11.385  INFO 20436 --- [nio-8899-exec-1] com.demo.controller.IndexController      : 剩余库存:0

**六、遗留问题**

当Redis为集群部署时，Redisson在Master主节点设置锁后，如果在Master节点同步锁到分机之前，Master宕机，则

分机会通过选举产生新的Master节点；此时锁丢失。。。

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[7dd403073ddf4888bf8d7d9d67a07cd2.png]: https://img-blog.csdnimg.cn/7dd403073ddf4888bf8d7d9d67a07cd2.png
[watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA54yq5oKf6YGT_size_20_color_FFFFFF_t_70_g_se_x_16 1]: https://img-blog.csdnimg.cn/06e2769462564eef8cdfc0e99036aefd.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBA54yq5oKf6YGT,size_20,color_FFFFFF,t_70,g_se,x_16
[6a2a70767db547f8b6be160b1297c708.png]: https://img-blog.csdnimg.cn/6a2a70767db547f8b6be160b1297c708.png