关于springcloud Gateway中的限流

我们在开发系统的时候可能会对系统进行限流的需求， springcloudGateway有自带限流的方案，在此之前可以先去学习一下springcloud gateway中的filter。

springcloud Gateway中提供了一个RequestRateLimiterGatewayFilterFactory。

这种限流方式用到了redis， 先添加 redis 的依赖。

配置类如下：

public class RemoteAddrKeyResolver implements KeyResolver {

    public static final String BEAN_NAME = "remoteAddrKeyResolver";

    @Override
    public Mono<String> resolve(ServerWebExchange exchange) {
        System.out.println("hello");
        Mono<String> just = Mono.just(exchange.getRequest().getRemoteAddress().getAddress().getHostAddress());
        return just;
    }
}

@Configuration
public class RemoteKeyResolver {

    @Bean(name="remoteAddrKeyResolver")
    public RemoteAddrKeyResolver remoteAddrKeyResolver() {
        return new RemoteAddrKeyResolver();
    }
}

在此我们是根据ip地址限流的， Mono<String> just = Mono.just(exchange.getRequest().getRemoteAddress().getAddress().getHostAddress())

application.yml配置文件配置如下：

spring:
  application:
    name: gateway-service
#  redis:
#    database: 0
#    host: localhost
#    port: 6379
#    password:
#    timeout: 1000ms
#    lettuce:
#      pool:
#        max-active: 8
#        max-idle: 8
#        min-idle: 1
#        max-wait: 1000ms
#  cache:
#    type: REDIS
  cloud:
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: order
          uri: lb://order-service
          predicates:
          - Path=/api/order-service/**
          filters:
          - StripPrefix=1
          - name: RequestRateLimiter
            args:
              key-resolver: '#{@remoteAddrKeyResolver}'
              redis-rate-limiter.replenishRate: 1
              redis-rate-limiter.burstCapacity: 2

上面贴出的是完整的springcloud Gateway的配置, 主要配置为filters下的-RequestRateLimiter,

key-resolver表示使用名为remoteAddKeyResolver的限流配置配置类，此限流方式采用的是令牌桶算法的限流方式

redis-rate-limiter.repleushRate ：令牌桶每秒填充平均速率。

redis-rate-limiter.burstCapacity: 令牌桶的总容量