spring cloud 2020 gateway 报错503

POM文件依赖

<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <!--gateway fhadmin.org--> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-gateway</artifactId> <version>3.0.2</version> </dependency> <!--spring-boot fhadmin.org--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> 

我在父组件中加入的nacos的相关依赖如下：

<dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId> <version>${nacos.version}</version> </dependency> <!--alibaba fhadmin.org--> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId> <version>${nacos.version}</version> </dependency> 

nacos的版本如下：

<properties> <nacos.version>2021.1</nacos.version> </properties> 

gateway的application.yml文件配置如下：

#fhadmin.org
server:
  port: 9040

spring:
  application:
    name: gateway
  cloud:
    gateway:
      routes:
        - id: consumer
          uri: lb://consumer
          #          uri: http://localhost:9010
          predicates:
            - Path=/**
    nacos:
      discovery:
        server-addr: localhost:8848
        metadata:
          preserved.heart.beat.interval: 3 #心跳间隔。时间单位:秒。心跳间隔
          preserved.heart.beat.timeout: 6 #心跳暂停。时间单位:秒。 即服务端6秒收不到客户端心跳，会将该客户端注册的实例设为不健康：
          preserved.ip.delete.timeout: 9 #Ip删除超时。时间单位:秒。即服务端9秒收不到客户端心跳，会将该客户端注册的实例删除：

当我通过uri: http://localhost:9010去调用服务时，是可以调用的，但是当我用uri lb://consumer时就无法调用服务，报错503.

解决办法是：
加入feign依赖。

<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-gateway</artifactId> <version>3.0.2</version> </dependency> <!--fegin组件 fhadmin.cn--> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> <version>3.0.2</version> </dependency> <!-- Feign Client for loadBalancing --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-loadbalancer</artifactId> <version>3.0.2</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> 

猜测原因：nacos兼容feign，feign集成ribbon，默认实现负载均衡；或许是nacos不兼容springcloud gateway自带的ribbon。