一、系统架构设计

本秒杀系统采用分层架构设计：

• 接入层：Nginx负载均衡 + 限流
• 应用层：SpringBoot微服务集群
• 缓存层：Redis集群 + 分布式锁
• 消息队列：RabbitMQ异步削峰
• 数据层：MySQL分库分表

二、核心代码实现

1. 分布式锁实现

public class RedisDistributedLock {
    private final StringRedisTemplate redisTemplate;
    private final String lockKey;
    private final String lockValue;
    private final long expireTime;

    public RedisDistributedLock(StringRedisTemplate redisTemplate, 
                              String lockKey, long expireTime) {
        this.redisTemplate = redisTemplate;
        this.lockKey = lockKey;
        this.lockValue = UUID.randomUUID().toString();
        this.expireTime = expireTime;
    }

    public boolean tryLock() {
        return redisTemplate.opsForValue()
            .setIfAbsent(lockKey, lockValue, expireTime, TimeUnit.MILLISECONDS);
    }

    public boolean unlock() {
        String script = "if redis.call('get', KEYS[1]) == ARGV[1] then " +
                       "return redis.call('del', KEYS[1]) " +
                       "else return 0 end";
        
        Long result = redisTemplate.execute(
            new DefaultRedisScript(script, Long.class),
            Collections.singletonList(lockKey),
            lockValue
        );
        
        return result != null && result == 1;
    }
}

2. 秒杀核心逻辑

@Service
public class SeckillService {
    @Autowired
    private RedisTemplate redisTemplate;
    @Autowired
    private RabbitTemplate rabbitTemplate;
    
    public Result seckill(long userId, long goodsId) {
        // 1. 校验秒杀状态
        Boolean isSeckill = redisTemplate.opsForValue()
            .getBit("seckill:goods:" + goodsId, userId);
        if (isSeckill != null && isSeckill) {
            return Result.error("请勿重复秒杀");
        }
        
        // 2. 预减库存
        Long stock = redisTemplate.opsForValue()
            .decrement("seckill:stock:" + goodsId);
        if (stock == null || stock < 0) {
            return Result.error("秒杀已结束");
        }
        
        // 3. 生成订单
        SeckillOrder order = new SeckillOrder();
        order.setUserId(userId);
        order.setGoodsId(goodsId);
        
        // 4. 异步处理
        rabbitTemplate.convertAndSend(
            "seckill.order.exchange",
            "seckill.order.routingKey",
            order
        );
        
        // 5. 标记已参与
        redisTemplate.opsForValue()
            .setBit("seckill:goods:" + goodsId, userId, true);
        
        return Result.success("秒杀成功");
    }
}

三、高并发优化方案

1. 缓存预热

@PostConstruct
public void initSeckillGoods() {
    List goodsList = goodsMapper.selectAll();
    goodsList.forEach(goods -> {
        String stockKey = "seckill:stock:" + goods.getId();
        redisTemplate.opsForValue().set(stockKey, goods.getStock());
    });
}

2. 库存分段优化

public Result seckill(long userId, long goodsId) {
    // 分段获取库存key
    int segment = (int) (userId % 10);
    String stockKey = "seckill:stock:" + goodsId + ":" + segment;
    
    // 其他逻辑不变...
}

四、安全防护措施

1. 接口限流：Guava RateLimiter实现
2. 验证码：防止机器人刷单
3. 隐藏秒杀地址：动态生成URL
4. 数据校验：前端+后端双重校验
5. 防脚本作弊：用户行为分析

五、性能测试指标