关于springcloud Gateway中的限流

川长思鸟来 2022-03-07 13:26 282阅读 0赞

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