基于Redis ZSet的滑动窗口限流

2024-10-29 17:25:11 2

private boolean limit() {

    String ip = ServletUtil.getClientIP(request);
    String banKey = "limit_ban_" + ip;
    Boolean b = redisTemplate.hasKey(banKey);
    if (Objects.nonNull(b) && b) {
        return false;
    }

    String key = "service_limit_" + ip;

    long currMs = System.currentTimeMillis();

    ZSetOperations<String, String> ops = redisTemplate.opsForZSet();
    
    // 根据score查最近半小时的新增元素
    Set<String> set = ops.rangeByScore(key, currMs - 1000 * 60 * 30.0, currMs);

    // 半小时内请求超过30次
    if (Objects.nonNull(set) && set.size() >= 30) {
        // 超过请求次数限制, 封禁30分钟
        redisTemplate.opsForValue().set(banKey, "1", 30, TimeUnit.MINUTES);
        return false;
    }

    // 将当前毫秒当成score存入zset
    // 请求一次存一次
    ops.add(key, Long.toString(currMs), currMs);
    redisTemplate.expire(key, 30, TimeUnit.MINUTES);

    return true
}

• redis
• java