分布式锁RedLock的java实现Redisson

2023-08-14 15:47:34

1. 概述
分布式锁RedLock的java实现RedissonRedisson是一个在Redis的基础上实现的Java驻内存数据网格（In-Memory Data Grid）。它不仅提供了一系列的分布式的Java常用对象，还提供了许多分布式服务。其中包括(BitSet, Set, Multimap, SortedSet, Map, List, Queue, BlockingQueue, Deque, BlockingDeque, Semaphore, Lock, AtomicLong, CountDownLatch, Publish / Subscribe, Bloom filter, Remote service, Spring cache, Executor service, Live Object service, Scheduler service) Redisson提供了使用Redis的最简单和最便捷的方法。Redisson的宗旨是促进使用者对Redis的关注分离（Separation of Concern），从而让使用者能够将精力更集中地放在处理业务逻辑上。

关于Redisson项目的详细介绍可以在官方网站找到。

每个Redis服务实例都能管理多达1TB的内存。

能够完美的在云计算环境里使用，并且支持AWS ElastiCache主备版，AWS ElastiCache集群版，Azure Redis Cache和阿里云（Aliyun）的云数据库Redis版

以下是Redisson的结构：

Redisson作为独立节点 可以用于独立执行其他节点发布到分布式执行服务 和 分布式调度任务服务 里的远程任务。
分布式锁RedLock的java实现Redisson
如果你现在正在使用其他的Redis的Java客户端，那么Redis命令和Redisson对象匹配列表 能够帮助你轻松的将现有代码迁徙到Redisson框架里来。
Redisson底层采用的是Netty 框架。支持Redis 2.8以上版本，支持Java1.6+以上版本。
欢迎试用高性能Redisson PRO版。

2.使用Redisson
2.1引入Maven依赖

<!-- JDK 1.8+ compatible -->
<dependency>
   <groupId>org.redisson</groupId>
   <artifactId>redisson</artifactId>
   <version>3.5.4</version>
</dependency>  
 
<!-- JDK 1.6+ compatible -->
<dependency>
   <groupId>org.redisson</groupId>
   <artifactId>redisson</artifactId>
   <version>2.10.4</version>
</dependency>

注意一下几点:
1：文档里面说明了支持Redis 2.8以上版本，支持Java1.6+以上版本。根据自己的环境选择合适的版本！
2：2.8.1的redisson 需要使用 netty的jar包， 否则报错：Hopper: java.lang.NoClassDefFoundError: io/netty/channel/EventLoopGroup。
3：2.8.1的redisson需要jackson 2.5+版本，否则报错bjectMapper.addMixIn method not fond。

2.2配置
Redisson配置文档
本文以哨兵模式为例分别给出 json yml xml

{
   "sentinelServersConfig":{
      "idleConnectionTimeout":10000,
      "connectTimeout":10000,
      "timeout":3000,
      "retryAttempts":3,
      "retryInterval":1500,
      "failedSlaveReconnectionInterval":3000,
      "failedSlaveCheckInterval":60000,
      "password":null,
      "subscriptionsPerConnection":5,
      "clientName":null,
      "loadBalancer":{
         "class":"org.redisson.connection.balancer.RoundRobinLoadBalancer"
      },
      "subscriptionConnectionMinimumIdleSize":1,
      "subscriptionConnectionPoolSize":50,
      "slaveConnectionMinimumIdleSize":32,
      "slaveConnectionPoolSize":64,
      "masterConnectionMinimumIdleSize":32,
      "masterConnectionPoolSize":64,
      "readMode":"SLAVE",
      "subscriptionMode":"SLAVE",
      "sentinelAddresses":[
         "redis://127.0.0.1:26379",
         "redis://127.0.0.1:26389"
      ],
      "masterName":"mymaster",
      "database":0
   },
   "threads":0,
   "nettyThreads":0,
   "codec":{
      "class":"org.redisson.codec.FstCodec"
   },
   "transportMode":"NIO"
}

sentinelServersConfig:
  idleConnectionTimeout: 10000
  connectTimeout: 10000
  timeout: 3000
  retryAttempts: 3
  retryInterval: 1500
  failedSlaveReconnectionInterval: 3000
  failedSlaveCheckInterval: 60000
  password: null
  subscriptionsPerConnection: 5
  clientName: null
  loadBalancer: !<org.redisson.connection.balancer.RoundRobinLoadBalancer> {}
  subscriptionConnectionMinimumIdleSize: 1
  subscriptionConnectionPoolSize: 50
  slaveConnectionMinimumIdleSize: 32
  slaveConnectionPoolSize: 64
  masterConnectionMinimumIdleSize: 32
  masterConnectionPoolSize: 64
  readMode: "SLAVE"
  subscriptionMode: "SLAVE"
  sentinelAddresses:
  - "redis://127.0.0.1:26379"
  - "redis://127.0.0.1:26389"
  masterName: "mymaster"
  database: 0
threads: 0
nettyThreads: 0
codec: !<org.redisson.codec.FstCodec> {}
transportMode: "NIO"

<redisson:client
    id="redisson"
    name="redisson1,redisson2"
    threads="0"
    netty-threads="0"
    codec-ref="myCodec" 
    transport-mode="NIO"
    reference-enabled="true"
    reference-codec-provider-ref="myCodecProvider"
    executor-ref="myExecutor"
    event-loop-group-ref="myEventLoopGroup"
>
    <!--
    You can't have both name attribute and qualifier element at
    the same time. 

    Both id attribute and name attribute can be used as qualifier
    candidates.
    -->
    <!--<qualifier value="redisson3"/>-->
    <redisson:sentinel-servers
        idle-connection-timeout="10000"
        ping-timeout="1000"
        connect-timeout="10000"
        timeout="3000"
        retry-attempts="3"
        retry-interval="1500"
        reconnection-timeout="3000"
        failed-attempts="3"
        password="do_not_use_if_it_is_not_set"
        subscriptions-per-connection="5"
        client-name="none"
        load-balancer-ref="myLoadBalancer"
        subscription-connection-minimum-idle-size="1"
        subscription-connection-pool-size="50"
        slave-connection-minimum-idle-size="10"
        slave-connection-pool-size="64"
        master-connection-minimum-idle-size="10"
        master-connection-pool-size="64"
        read-mode="SLAVE"
        subscription-mode="SLAVE"
        master-name="myMaster"
        database="0"
    >
        <redisson:sentinel-address value="redis://127.0.0.1:26379" />
        <redisson:sentinel-address value="redis://127.0.0.1:26380" />
    </redisson:sentinel-servers>
</redisson:client>

<!-- minimal settings -->
<redisson:client>
    <redisson:sentinel-servers master-name="myMaster">
        <redisson:sentinel-address value="redis://127.0.0.1:26379" />
        <redisson:sentinel-address value="redis://127.0.0.1:26380" />
        ....
    </redisson:sentinel-servers>
</redisson:client>

2.3举个栗子

 Config config = new Config();
        config.useSentinelServers().setMasterName("dongshuo").addSentinelAddress("redis://127.0.0.1:6379");
        RedissonClient redissonClient = Redisson.create(config);

        RLock lock = redissonClient.getLock("dongshuo");
        lock.lock(1000, TimeUnit.SECONDS);
        try {
            System.out.println("获取到Redisson锁");
        }
        finally {
            lock.unlock();
        }
        redissonClient.shutdown();
  •  

2.4监控Redis命令

127.0.0.1:6379> monitor
OK
1434959509.494805 [0 127.0.0.1:57911] "SETNX" "dongshuo" "{\"@class\":\"org.redisson.RedissonLock$LockValue\",\"counter\":1,\"id\":\"c374addc-523f-4943-b6e0-c26f7ab061e3\",\"threadId\":1}"
1434959509.494805 [0 127.0.0.1:57911] "GET" "dongshuo"
1434959509.524805 [0 127.0.0.1:57911] "MULTI"
1434959509.529805 [0 127.0.0.1:57911] "DEL" "dongshuo"
1434959509.529805 [0 127.0.0.1:57911] "PUBLISH" "redisson__lock__channel__{dongshuo}" "0"
1434959509.529805 [0 127.0.0.1:57911] "EXEC"
  •  

看起来还是用到了sentnx命令\

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