【Redis】1. redission分布式锁

模拟扣库存服务，不加任何锁：

<dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

package com.hknetty.redis;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;


@RestController
public class IndexContrpller {
    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @GetMapping("/deduct_stock")
    public String deductStock() {
        //商品ID
        String lockKey = "product_001";

        try {
            //模拟从数据库取库存
            Integer stock = Integer.parseInt(stringRedisTemplate.opsForValue().get("stock"));

            if (stock > 0) {
                int realStock = stock - 1;
                stringRedisTemplate.opsForValue().set("stock", realStock + "");
                System.out.println("扣库存成功，剩余库存："+realStock);
            }else{
                System.out.println("扣库存失败，库存不足。");
            }


        } finally {
        }

        return null;
    }

}

启动端口：8080  8081  8082

配置nginx负载：

配置Redis库存数：

配置压测：

启动压测看库存结果：

加redission分布式锁

        <dependency>
            <groupId>org.redisson</groupId>
            <artifactId>redisson</artifactId>
            <version>3.6.5</version>
        </dependency>

启动类注入bean： 

    /**
     * Redission分布式锁
     */
    @Bean
    public Redisson redission() {
        //单机模式
        Config config = new Config();
        config.useSingleServer().setAddress("redis://127.0.0.1:6379").setDatabase(0);

        //分布式版本
//        config.useClusterServers()
//                .addNodeAddress("redis://127.0.0.1:6379")
//                .addNodeAddress("redis://127.0.0.2:6379")
//                .addNodeAddress("redis://127.0.0.3:6379");

        return (Redisson) Redisson.create(config);

    }

改造扣库存类：

package com.hknetty.redis;

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.GetMapping;
import org.springframework.web.bind.annotation.RestController;


@RestController
public class IndexContrpller {
    @Autowired
    private Redisson redisson;
    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @GetMapping("/deduct_stock")
    public String deductStock() {
        //商品ID
        String lockKey = "product_001";

        RLock rLock = redisson.getLock(lockKey);

        //给业务加锁  续命
        try {
            rLock.lock();
            //模拟从数据库取库存
            Integer stock = Integer.parseInt(stringRedisTemplate.opsForValue().get("stock"));

            if (stock > 0) {
                int realStock = stock - 1;
                stringRedisTemplate.opsForValue().set("stock", realStock + "");
                System.out.println("扣库存成功，剩余库存："+realStock);
            }else{
                System.out.println("扣库存失败，库存不足。");
            }


        } finally {
            //关闭锁
            rLock.unlock();
        }

        return null;
    }

}

启动端口：8080  8081  8082

修改Redis库存到10000

开始压测：

来源：oschina

链接：https://my.oschina.net/u/1046143/blog/3223411