引入RedisRateLimiter

1.类路径：

org.springframework.cloud.gateway.filter.ratelimit.RedisRateLimiter
spring.cloud.gateway.redis-rate-limiter

2.内部类路径：

org.springframework.cloud.gateway.filter.ratelimit.RedisRateLimiter.Config
spring.cloud.gateway.redis-rate-limiter.replenishRate：最小值1
spring.cloud.gateway.redis-rate-limiter.burstCapacity：最小值1

3.进入isAllowed方法

redis两个key
request_rate_limiter.{id}.timestamp：最细维度到秒，当前时间
request_rate_limiter.{id}.tokens：当前时间戳对应令牌数

4.redis lua脚本处理

5.状态码

6.redis集群导致问题

io.lettuce.core.RedisCommandExecutionException: ERR bad lua script for redis cluster, all the keys that the script uses should be passed using the KEYS array, and KEYS should not be in expression

报错解决方式
@see 
https://blog.csdn.net/qq_33996921/article/details/107204362
https://www.codeleading.com/article/99294719734/