REDIS学习总结（三）REDIS集群下分布式锁学习与SpringBoot秒杀场景简单实践
主要内容：
一、什么是分布式锁？
二、分布式锁的业务应用场景
三、REDIS分布式锁的构建
四、SpringBoot+Redis集群的"减库存"粗糙实践
五、遇到的问题与解决
六、待学习的文章
一、什么是分布式锁？
我最初的理解：例如在减库存的场景下，多个线程并发访问DB或redis集群时，锁是用来同步多线程操作集群中的一个共享变量标记，使该共享变量不会发生"超卖"现象。
推荐学习这篇文章 “分布式锁的一点理解” 这样理解分布式锁：
1.分布式与单机情况下最大的不同在于其不是多线程而是多进程。
2.多线程由于可以共享堆内存，因此可以简单的采取内存作为标记存储位置。而进程之间甚至可能都不在同一台物理机上，因此需要将标记存储在一个所有进程都能看到的地方。
3.当在分布式模型下，数据只有一份（或有限制），此时需要利用锁的技术控制某一时刻修改数据的进程数。
4.与单机模式下的锁不仅需要保证进程可见，还需要考虑进程与锁之间的网络问题。
5.分布式锁还是可以将标记存在内存，只是该内存不是某个进程分配的内存而是公共内存如Redis、Memcache。至于利用数据库、文件等做锁与单机的实现是一样的，只要保证标记能互斥就行。
再推荐这篇文章 “分布式锁的作用及实现（Redis）”
二、分布式锁的业务应用场景
秒杀减库存、全局increase、楼层生成、分布式调度等
三、REDIS分布式锁的构建
这里直接提供传送门，不再COPY
1.《Redis官方文档》用Redis构建分布式锁
2. redis分布式锁安全性探讨（一）：基于单个redis节点的分布式锁
3. redis分布式锁的安全性探讨（二）：分布式锁Redlock
4. Redis学习笔记（六）redis实现分布式锁
四、SpringBoot+Redis集群的"减库存"简单实践
1.参见 REDIS学习总结（一）单机集群搭建
2.SpringBoot项目搭建
pom.xml文件依赖：
<?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>2.1.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.jupiter.redis.test</groupId>
<artifactId>redis-learn</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>redis-learn</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.redisson</groupId>
<artifactId>redisson</artifactId>
<version>3.10.0</version>
</dependency>
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.25.Final</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.54</version>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>3.0.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis-reactive</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</projectFastJson2RedisJsonSerializer、RedisLearnApplication、application.properties、redis.properties 见 REDIS学习总结（二）Java操作redis集群
RedisConfig内容(--2019-01-31 update--)
package com.jupiter.redis.commons;
import java.time.Duration;
import java.util.HashSet;
import java.util.Set;
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.PropertySource;
import org.springframework.data.redis.connection.RedisClusterConfiguration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.connection.RedisNode;
import org.springframework.data.redis.connection.jedis.JedisClientConfiguration;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import org.springframework.stereotype.Component;
import com.alibaba.fastjson.parser.ParserConfig;
import redis.clients.jedis.HostAndPort;
import redis.clients.jedis.JedisCluster;
import redis.clients.jedis.JedisPoolConfig;
/*
* @author Jupiter
* @date 2019/1/20-23:41
* @description redis配置
*/
@Component
@PropertySource("classpath:redis.properties")
public class RedisConfig {
@Value("${spring.redis.cluster.nodes}")
private String clusterNodes;
@Value("${redis.cache.timeout}")
private int timeout;
@Value("${redis.pool.max-idle}")
private int maxIdle;
@Value("${redis.pool.max-wait}")
private long maxWaitMillis;
@Value("${redis.cache.commandTimeout}")
private int commandTimeout;
@Bean
public RedisSerializer fastJson2JsonRedisSerializer(){
ParserConfig.getGlobalInstance().setAutoTypeSupport(true);
return new FastJson2RedisJsonSerializer<Object>(Object.class);
}
@Bean
public Redisson redisson() {
//支持单机，主从，哨兵，集群等模式
String[] cNodes = clusterNodes.split(",");
Config config = new Config();
for (String node:cNodes) {
config.useClusterServers().addNodeAddress("redis://"+node);
}
return (Redisson)Redisson.create(config);
}
@Bean
public JedisCluster getJedisCluster() {
String[] cNodes = clusterNodes.split(",");
Set<HostAndPort> nodes =new HashSet<>();
//分割出集群节点
for(String node : cNodes) {
String[] hp = node.split(":");
nodes.add(new HostAndPort(hp[0], Integer.parseInt(hp[1])));
}
JedisPoolConfig jedisPoolConfig =new JedisPoolConfig();
jedisPoolConfig.setMaxIdle(maxIdle);
jedisPoolConfig.setMaxWaitMillis(maxWaitMillis);
//创建集群对象
return new JedisCluster(nodes,timeout,jedisPoolConfig);
}
@Bean
public RedisTemplate<Object,Object> redisTemplate(RedisConnectionFactory redisConnectionFactory){
RedisTemplate<Object,Object> redisTemplate = new RedisTemplate<>();
redisTemplate.setConnectionFactory(redisConnectionFactory);
//使用fastjson做序列化
FastJson2RedisJsonSerializer fastJson2RedisJsonSerializer = new FastJson2RedisJsonSerializer(Object.class);
redisTemplate.setValueSerializer(fastJson2RedisJsonSerializer);
redisTemplate.setKeySerializer(new StringRedisSerializer());
redisTemplate.afterPropertiesSet();
return redisTemplate;
}
public RedisConnectionFactory connectionFactory() {
JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMaxIdle(maxIdle);
poolConfig.setTestOnBorrow(true);
poolConfig.setTestOnReturn(false);
poolConfig.setTestWhileIdle(true);
JedisClientConfiguration clientConfig = JedisClientConfiguration.builder()
.usePooling().poolConfig(poolConfig).and().readTimeout(Duration.ofMillis(timeout)).build();
// 单点redis
//RedisStandaloneConfiguration redisConfig = new RedisStandaloneConfiguration();
// 哨兵redis
// RedisSentinelConfiguration redisConfig = new RedisSentinelConfiguration();
// 集群redis
RedisClusterConfiguration redisConfig = new RedisClusterConfiguration();
String[] cNodes = clusterNodes.split(",");
Set<RedisNode> nodes =new HashSet<>();
//分割出集群节点
for(String node : cNodes) {
String[] hp = node.split(":");
nodes.add(new RedisNode(hp[0], Integer.parseInt(hp[1])));
}
redisConfig.setClusterNodes(nodes);
//redisConfig.setPassword(RedisPassword.of(redisAuth));
return new JedisConnectionFactory(redisConfig, clientConfig);
}
}RushController内容：
package com.jupiter.redis.controller;
import lombok.extern.slf4j.Slf4j;
import org.redisson.Redisson;
import org.redisson.api.RLock;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
/**
* @author Jupiter
* @date 2019/1/28-19:45
* @description 秒杀请求Controller,当然前端要层层过滤,过滤掉
*/
@RestController
@Slf4j
public class RushController {
private static String commodityCount = "commodityCount";//商品总数key
private static String lockKey = "testRedisson";//分布式锁的key
@Autowired
private StringRedisTemplate redisTemplate;
@Autowired private Redisson redisson;
/** 初步测试计数，统计压测访问请求成功数 .*/
private int cnt = 0;
/**
* 设置商品数量为100个
* @return
*/
@RequestMapping("/setValue")
public String setValue(){
//商品名称、数量设置成可配置
redisTemplate.opsForValue().set(commodityCount , "100");
return "success";
}
/**
* 模拟抢购，使用Jmeter进行并发压测，查看是否出现超卖
* @return
*/
@RequestMapping("/rushGoods")
public String spike(){
String flag = "success";
//获取redis分布式锁
RLock lock = redisson.getLock(lockKey);
try{
//获取锁的等待时间、锁的自动释放时间设置（这里可以进行配置优化）
Future<Boolean> res = lock.tryLockAsync(100, 5, TimeUnit.SECONDS);
boolean result = res.get();
//拿到锁才能进行下一步
if(result){
int stock = Integer.parseInt(redisTemplate.opsForValue().get(commodityCount).toString());
if(stock > 0){
redisTemplate.opsForValue().set(commodityCount,(stock-1)+"");
}else{
flag = "fail";
}
log.info("第"+(cnt++)+"个线程："+(flag.equals("success")?"成功买到":"没买到"));
}
}catch (Exception e){
e.printStackTrace();
}
finally{
lock.unlock(); //释放锁
}
//如果释放锁失败，是不会返回“success”的，因为直接跑出异常了
return flag;
}
}3.秒杀测试
首先，启动运行Spring工程
① 浏览器访问localhost:8080/setValue 进行商品数量设置，DEMO中写的固定100，可在redis中get一下commodityCount
② 使用Jmeter进行压力测试，设置如下：
③ 运行测试（Ctrl+E清空测试），可以看到，Jmeter在1秒内压入1000并发请求（更大并发测试还要看机器性能或者搭建Jmeter测试集群，前端设置个代理执行），而tomcat响应4秒多，没报错，但更大并发会报错，推荐看 五、六两部分
2019-01-30 22:47:38.770 INFO 16816 --- [io-8080-exec-10] c.j.redis.controller.RushController : 第0个线程：成功买到
2019-01-30 22:47:38.842 INFO 16816 --- [io-8080-exec-39] c.j.redis.controller.RushController : 第1个线程：成功买到
2019-01-30 22:47:39.231 INFO 16816 --- [io-8080-exec-59] c.j.redis.controller.RushController : 第2个线程：成功买到
2019-01-30 22:47:39.332 INFO 16816 --- [io-8080-exec-84] c.j.redis.controller.RushController : 第3个线程：成功买到
2019-01-30 22:47:39.341 INFO 16816 --- [io-8080-exec-71] c.j.redis.controller.RushController : 第4个线程：成功买到
2019-01-30 22:47:39.346 INFO 16816 --- [io-8080-exec-48] c.j.redis.controller.RushController : 第5个线程：成功买到
......
2019-01-30 22:47:40.152 INFO 16816 --- [o-8080-exec-155] c.j.redis.controller.RushController : 第99个线程：成功买到
2019-01-30 22:47:40.156 INFO 16816 --- [o-8080-exec-154] c.j.redis.controller.RushController : 第100个线程：没买到
2019-01-30 22:47:40.158 INFO 16816 --- [o-8080-exec-155] c.j.redis.controller.RushController : 第101个线程：没买到
2019-01-30 22:47:40.161 INFO 16816 --- [o-8080-exec-154] c.j.redis.controller.RushController : 第102个线程：没买到
2019-01-30 22:47:40.163 INFO 16816 --- [o-8080-exec-155] c.j.redis.controller.RushController : 第103个线程：没买到
2019-01-30 22:47:40.166 INFO 16816 --- [o-8080-exec-154] c.j.redis.controller.RushController : 第104个线程：没买到
2019-01-30 22:47:40.168 INFO 16816 --- [o-8080-exec-155] c.j.redis.controller.RushController : 第105个线程：没买到
2019-01-30 22:47:40.172 INFO 16816 --- [o-8080-exec-154] c.j.redis.controller.RushController : 第106个线程：没买到
2019-01-30 22:47:40.175 INFO 16816 --- [o-8080-exec-155] c.j.redis.controller.RushController : 第107个线程：没买到
2019-01-30 22:47:40.179 INFO 16816 --- [o-8080-exec-154] c.j.redis.controller.RushController : 第108个线程：没买到
2019-01-30 22:47:40.182 INFO 16816 --- [o-8080-exec-155] c.j.redis.controller.RushController : 第109个线程：没买到
2019-01-30 22:47:40.186 INFO 16816 --- [o-8080-exec-154] c.j.redis.controller.RushController : 第110个线程：没买到
......
2019-01-30 22:47:42.906 INFO 16816 --- [o-8080-exec-180] c.j.redis.controller.RushController : 第999个线程：没买到注：以上"第XX个线程"并非实际线程访问顺序，只是计入秒杀方法的线程计数而已
五、遇到的问题与解决
问题一：o.r.cluster.ClusterConnectionManager:connection timed out: 使用本地可以ping同centos，但是就是出现connect timed out,原因：centos的防火墙没有关闭。
解决：查询防火墙状态：systemctl status firewalld.service 打开方法：systemctl start firewalld.service 关闭方法：systemctl stop firewalld.service
问题二：高并发压测异常（1秒3000并发）解决见：秒杀系统架构优化思路
2019-01-29 20:45:16.460 ERROR 25132 --- [http-nio-8080-exec-23] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.IllegalMonitorStateException: attempt to unlock lock, not locked by current thread by node id: c35ec7ec-d76b-493f-b2a7-cec1c8b85668 thread-id: 2015] with root cause
java.lang.IllegalMonitorStateException: attempt to unlock lock, not locked by current thread by node id: c35ec7ec-d76b-493f-b2a7-cec1c8b85668 thread-id: 2015
at org.redisson.RedissonLock$5.operationComplete(RedissonLock.java:521) ~[redisson-3.10.0.jar:na]
at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:511) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:504) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:483) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:424) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.DefaultPromise.trySuccess(DefaultPromise.java:103) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at org.redisson.misc.RedissonPromise.trySuccess(RedissonPromise.java:88) ~[redisson-3.10.0.jar:na]
at org.redisson.command.CommandAsyncService.handleReference(CommandAsyncService.java:1081) ~[redisson-3.10.0.jar:na]
at org.redisson.command.CommandAsyncService.handleSuccess(CommandAsyncService.java:1074) ~[redisson-3.10.0.jar:na]
at org.redisson.command.CommandAsyncService.checkAttemptFuture(CommandAsyncService.java:1056) ~[redisson-3.10.0.jar:na]
at org.redisson.command.CommandAsyncService$12.operationComplete(CommandAsyncService.java:811) ~[redisson-3.10.0.jar:na]
at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:511) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:504) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:483) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:424) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.DefaultPromise.trySuccess(DefaultPromise.java:103) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at org.redisson.misc.RedissonPromise.trySuccess(RedissonPromise.java:88) ~[redisson-3.10.0.jar:na]
at org.redisson.client.handler.CommandDecoder.completeResponse(CommandDecoder.java:415) ~[redisson-3.10.0.jar:na]
at org.redisson.client.handler.CommandDecoder.handleResult(CommandDecoder.java:410) ~[redisson-3.10.0.jar:na]
at org.redisson.client.handler.CommandDecoder.decode(CommandDecoder.java:332) ~[redisson-3.10.0.jar:na]
at org.redisson.client.handler.CommandDecoder.decodeCommand(CommandDecoder.java:130) ~[redisson-3.10.0.jar:na]
at org.redisson.client.handler.CommandDecoder.decode(CommandDecoder.java:110) ~[redisson-3.10.0.jar:na]
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489) ~[netty-codec-4.1.22.Final.jar:4.1.22.Final]
at io.netty.handler.codec.ReplayingDecoder.callDecode(ReplayingDecoder.java:367) ~[netty-codec-4.1.22.Final.jar:4.1.22.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265) ~[netty-codec-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1414) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:945) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:146) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:645) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:580) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:497) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459) ~[netty-transport-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.22.Final.jar:4.1.22.Final]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_91]问题三：高并发压测异常（1秒10000并发）解决：秒杀系统架构优化思路
[redisson-netty-14-13] o.r.client.handler.CommandDecoder : Unable to decode data.
六、待学习的文章
1. 电商商品秒杀系统架构分析与实战
2. 秒杀系统架构优化思路
3. JAVA构建高并发商城秒杀系统——架构分析
4. 秒杀系统架构分析与实战
5. redisson的理解和使用－调用流程
6. Redisson源码
其他参考文献：
1. SpringBoot项目开发(十五)：redisson实现分布式锁 （集群）
2. 如何用Redlock实现分布式锁
3. Redis分布式锁的正确实现方式 （单实例REDIS）
4. Redisson分布式锁
5. Redisson分布式锁实现
6. SpringBoot集成redisson分布式锁