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服务注册中心的迁移有多种方式，官网使用nacos sync，还有民间开发的双注册中心组件eureka-nacos-proxy，但是我用了不太顺利，所以用的是阿里巴巴的双注册中心组件edas-sc-migration-starter

spring boot：2.5.3

1. 引入依赖

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    <version>2.0.4.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba.cloud/spring-cloud-starter-alibaba-nacos-config -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
    <version>2.0.4.RELEASE</version>
</dependency>
<dependency>
    <groupId>com.alibaba.edas</groupId>
    <artifactId>edas-sc-migration-starter</artifactId>
    <version>1.0.2</version>
</dependency>

2. 正常启动即可发现两边都已经注册

3. 如果要用open feign，需要在启动类排除ribbon自动配置，否则服务间调用会报错

2021-08-18 16:00:58.368 ERROR 351892 --- [nio-8081-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Handler dispatch failed; nested exception is java.lang.AbstractMethodError: org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.choose(Ljava/lang/String;Lorg/springframework/cloud/client/loadbalancer/Request;)Lorg/springframework/cloud/client/ServiceInstance;] with root cause

java.lang.AbstractMethodError: org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.choose(Ljava/lang/String;Lorg/springframework/cloud/client/loadbalancer/Request;)Lorg/springframework/cloud/client/ServiceInstance;
 at org.springframework.cloud.openfeign.loadbalancer.FeignBlockingLoadBalancerClient.execute(FeignBlockingLoadBalancerClient.java:88) ~[spring-cloud-openfeign-core-3.0.3.jar:3.0.3]

点进去可以看到 应该是负载均衡时选择服务出现错误

解决方案1. 在启动类屏蔽ribbon自动配置类

此时feign会默认调用nacos的服务

方案2. 阿里云官网看的，但是我试了会报另一个错误，所以就采用方案1