Spring Cloud Gateway——2020.x以上版本HTTP 503 或 NoLoadBalancer[负载均衡]解决方案

Posted 2022-02-04 Starzkg

问题描述

config

spring:
  cloud:
    gateway:
      routes:
      - id: myRoute
        uri: lb://service
        predicates:
        - Path=/service/**

dependencyManagement

    <dependencyManagement>
        <dependencies>
            <!--Spring Boot-->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>$spring.boot.version</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--Spring Cloud-->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>$spring.cloud.version</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--Spring Cloud Alibaba-->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2021.1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--Alibaba Aliyun-->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>aliyun-spring-boot-dependencies</artifactId>
                <version>1.0.0</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

问题分析

spring-cloud-starter-gateway不再依赖默认的LoadBalancer，需要引入spring-cloud-starter-loadbalancer，并且无法解析http服务名称，例如：http://servicename,也无法访问。

      - id: user
        uri: http://user
        predicates:
        - Path=/user/**
        filters:
        - StripPrefix=1

解决方案

    <dependencies>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
    </dependencies>

参考文章

• springcloud 2020 gateway 503 错误代码
• springcloud2020版本gateway+nacos，服务报错503 Service Unavailable