SpringCloud基于Nacos和Eureka 实现双注册双订阅模式,可用于将注册中心Eureka平滑过渡到Nacos的解决方案

前言

大概在去年的时候发现生产环境使用eureka经常会发现服务假死eureka没有给踢掉的情况,然后就衍生了要不就换个注册中心试试,然后就了解到了nacos,正好他还融合了配置中心,但是后来碍于切换时怕生产环境不稳定,丢数据等问题就一直没有换,但后续的项目的注册中心都换成了nacos,这篇文章我就来模拟一下如何将eureka平滑切换成nacos

父工程构建

这里我在父工程里边又单独创建了一层父工程,我分别在alibaba-cloud 、netflix-cloud 中模拟新旧微服务
在这里插入图片描述

父工程pom

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>top.fate</groupId>
    <artifactId>nacoAndEureka</artifactId>
    <packaging>pom</packaging>
    <version>1.0.0</version>
    <modules>
        <module>netflix-cloud</module>
        <module>alibaba-cloud</module>
    </modules>
</project>

模拟旧版微服务

 netflix-cloud pom如下 ,因为这里是模拟旧服务,所以都采用旧版本
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>nacoAndEureka</artifactId>
        <groupId>top.fate</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>netflix-cloud</artifactId>
    <packaging>pom</packaging>
    <modules>
        <module>eureka</module>
        <module>eureka-provider</module>
        <module>eureka-consumer</module>
    </modules>

    <properties>
        <spring.boot.version>2.1.2.RELEASE</spring.boot.version>
        <spring.cloud.version>Greenwich.SR5</spring.cloud.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- springBoot -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- springCloud -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

</project>

搭建eureka

在这里插入图片描述

  • pom依赖如下
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>netflix-cloud</artifactId>
        <groupId>top.fate</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>eureka</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
    </dependencies>
</project>
  • EurekaApplication 启动类
package top.fate.eureka;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@EnableEurekaServer
@SpringBootApplication
public class EurekaApplication {
    
    

	public static void main(String[] args) {
    
    
		SpringApplication.run(EurekaApplication.class, args);
	}
}
  • application.yml
server:
  port: 8761
spring:
  application:
    name: eureka-service
eureka:
  instance:
    # 设置该服务注册中心的hostname
    hostname: 127.0.0.1
  client:
    # 我们创建的是服务注册中心,而不是普通的应用,这个应用会向注册中心注册它自己
    #,设置为false就是禁止自己向自己注册的这个种行为
    register-with-eureka: false
    # 不去检索其他的服务,因为注册中心本身的职责就是维护服务实例
    fetch-registry: false
    # 制定服务注册中心的位置
    service-url.defaultZone: http://${
    
    eureka.instance.hostname}:${
    
    server.port}/eureka/

eureka-provider

在这里插入图片描述

  • pom依赖如下
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>netflix-cloud</artifactId>
        <groupId>top.fate</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>eureka-provider</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>

</project>
  • EurekaProviderApplication 启动类
package top.fate.eurekaprovider;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @auther:Wangxl
 * @Emile:[email protected]
 * @Time:2022/6/16 14:23
 */
@SpringBootApplication
@EnableEurekaClient
@RestController
public class EurekaProviderApplication {
    
    
    public static void main(String[] args) {
    
    
        SpringApplication.run(EurekaProviderApplication.class, args);
    }

    @GetMapping("/info")
    public String info(){
    
    
        return "this is eureka-service";
    }
}

  • application.yml
server:
  port: 8081
spring:
  application:
    name: provider
eureka:
  client:
    service-url:
      defaultZone: "http://localhost:8761/eureka"

eureka-consumer

在这里插入图片描述

  • pom依赖如下
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>netflix-cloud</artifactId>
        <groupId>top.fate</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>eureka-consumer</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>io.github.openfeign</groupId>
            <artifactId>feign-httpclient</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
    </dependencies>
</project>
  • EurekaConsumerApplication 启动类
package top.fate.eurekaconsumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
import top.fate.eurekaconsumer.client.EurekaProviderClient;

/**
 * @auther:Wangxl
 * @Emile:[email protected]
 * @Time:2022/6/16 14:43
 */
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients(clients = EurekaProviderClient.class)
public class EurekaConsumerApplication {
    
    
    public static void main(String[] args) {
    
    
        SpringApplication.run(EurekaConsumerApplication.class, args);
    }
}
  • EurekaProviderClient
package top.fate.eurekaconsumer.client;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;

/**
 * @auther:Wangxl
 * @Emile:[email protected]
 * @Time:2022/6/16 14:48
 */
@FeignClient(value = "provider")
public interface EurekaProviderClient {
    
    

    @GetMapping("info")
    String info();
}
  • ConsumerController
package top.fate.eurekaconsumer.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import top.fate.eurekaconsumer.client.EurekaProviderClient;

import javax.annotation.Resource;

/**
 * @auther:Wangxl
 * @Emile:[email protected]
 * @Time:2022/6/16 14:48
 */
@RestController
public class ConsumerController {
    
    

    @Resource
    private EurekaProviderClient eurekaProviderClient;

    @GetMapping("getProvider")
    public String getProvider(){
    
    
        return eurekaProviderClient.info();
    }

}

测试服务是否可以调通

在这里插入图片描述
在这里插入图片描述

这里我三个服务都启动正常,直接访问8091consumer测试 ,如下图所示consumer 可以访问provider
在这里插入图片描述

第一阶段流程图

在这里插入图片描述


模拟新版微服务

alibaba-cloud pom如下,采用最新版技术栈
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>nacoAndEureka</artifactId>
        <groupId>top.fate</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>alibaba-cloud</artifactId>
    <packaging>pom</packaging>
    <modules>
        <module>nacos-consumer</module>
        <module>nacos-provider</module>
    </modules>

    <properties>
        <spring.boot.version>2.6.3</spring.boot.version>
        <spring.cloud.version>2021.0.1</spring.cloud.version>
        <spring.cloud.alibaba.version>2021.0.1.0</spring.cloud.alibaba.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- springBoot -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- springCloud -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${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>${spring.cloud.alibaba.version}</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

启动安装nacos

可以参考SpringCloudAlibaba篇(二)整合Nacos注册配置中心 这篇文章我就不重复操作了


nacos-provider

  • pom 依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>alibaba-cloud</artifactId>
        <groupId>top.fate</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>nacos-provider</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>2021.0.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>
</project>
  • NacosProviderApplication 启动类
package top.fate.nacosprovider;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationProperties;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @auther:Wangxl
 * @Emile:[email protected]
 * @Time:2022/6/16 16:55
 */
@SpringBootApplication
@RestController
@EnableConfigurationProperties(AutoServiceRegistrationProperties.class)
public class NacosProviderApplication {
    
    

    public static void main(String[] args) {
    
    
        SpringApplication.run(NacosProviderApplication.class, args);
    }

    @GetMapping("/info")
    public String info() {
    
    
        return "this is nacos-service";
    }
}
  • application.properties
spring.autoconfigure.exclude=org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration
  • application.yml
url:
  nacos: localhost:8848
server:
  port: 8082
spring:
  application:
    name: provider
  profiles:
    active: dev
  cloud:
    nacos:
      discovery:
        #集群环境隔离
        cluster-name: shanghai
        #命名空间
        namespace: ${
    
    spring.profiles.active}
        #持久化实例 ture为临时实例 false为持久化实例  临时实例发生异常直接剔除, 而持久化实例等待恢复
        ephemeral: true
        #注册中心地址
        server-addr: ${
    
    url.nacos}
eureka:
  client:
    service-url:
      defaultZone: "http://localhost:8761/eureka"

nacos-consumer

  • pom依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>alibaba-cloud</artifactId>
        <groupId>top.fate</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>nacos-consumer</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>2021.0.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>io.github.openfeign</groupId>
            <artifactId>feign-httpclient</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
    </dependencies>
</project>
  • NacosConsumerApplication 启动类
package top.fate.nacosconsumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationProperties;
import org.springframework.cloud.openfeign.EnableFeignClients;
import top.fate.nacosconsumer.client.EurekaProviderClient;
import top.fate.nacosconsumer.client.NacosProviderClient;
import top.fate.nacosconsumer.client.ProviderClient;

/**
 * @auther:Wangxl
 * @Emile:[email protected]
 * @Time:2022/6/16 16:39
 */
@SpringBootApplication
@EnableFeignClients(clients = {
    
    EurekaProviderClient.class, NacosProviderClient.class, ProviderClient.class})
@EnableConfigurationProperties(AutoServiceRegistrationProperties.class)
public class NacosConsumerApplication {
    
    

    public static void main(String[] args) {
    
    
        SpringApplication.run(NacosConsumerApplication.class, args);
    }
}
  • ProviderClient
package top.fate.nacosconsumer.client;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;

/**
 * @auther:Wangxl
 * @Emile:[email protected]
 * @Time:2022/6/16 18:24
 */
@FeignClient(value = "provider")
public interface ProviderClient {
    
    

    @GetMapping("info")
    String info();
}
  • ConsumerController
package top.fate.nacosconsumer.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import top.fate.nacosconsumer.client.ProviderClient;

import javax.annotation.Resource;

/**
 * @auther:Wangxl
 * @Emile:[email protected]
 * @Time:2022/6/16 14:48
 */
@RestController
public class ConsumerController {
    
    

    @Resource
    private ProviderClient providerClient;

    @GetMapping("getProvider")
    public String getProvider(){
    
    
        return providerClient.info();
    }
}
  • application.properties
spring.autoconfigure.exclude=org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration
  • application.yml
url:
  nacos: localhost:8848
server:
  port: 8092
spring:
  application:
    name: nacos-consumer
  profiles:
    active: dev
  cloud:
    nacos:
      discovery:
        #集群环境隔离
        cluster-name: shanghai
        #命名空间
        namespace: ${
    
    spring.profiles.active}
        #持久化实例 ture为临时实例 false为持久化实例  临时实例发生异常直接剔除, 而持久化实例等待恢复
        ephemeral: true
        #注册中心地址
        server-addr: ${
    
    url.nacos}
eureka:
  client:
    service-url:
      defaultZone: "http://localhost:8761/eureka"

上线双注册双订阅新provider服务

先启动nacosProviderApplication
在这里插入图片描述

如下图所示,我们已经实现了双注册,nacos和eureka中都注册了服务

nacos
在这里插入图片描述

eureka
在这里插入图片描述


平滑切换注册中心

验证旧consumer

这里我访问8091的旧版Netflix客户端也就是eureka-consumer,看一下调用的是8081 eureka 还是8082 nacos , 这里我反复调用了十几次,返回结果为

  • this is nacos-service
  • this is eureka-service
    因为此时我们的8091客户端只有eurekaClient,然后我们的provider在eureka注册中心有两个实例,所以就触发了负载均衡,这里我们用的默认轮询模式,当前流程如下图

在这里插入图片描述

下线旧provider

现在我们就可以陆续开始平滑切换注册中心了,旧provider可以关掉了,关掉旧provider之后此时的流程就如下图所示了
在这里插入图片描述

此时我们再访问旧consumer只会返回 this is nacos-service,因为旧的provider已经下线了 ,新provider当前已经切换完成!
在这里插入图片描述

上线双注册双订阅新consumer服务,下线旧consumer

启动nacoConsumerApplication
在这里插入图片描述
访问8092验证是否能正常访问,继续访问getProvider接口,如下图所示访问正常,然后我们就可以下线旧consumer服务了
在这里插入图片描述
在这里插入图片描述

疑惑 (该步骤可以直接略过)

现在我们有个疑惑,现在有两个注册中心,服务发现是走的eureka还是nacos呢
为此,我做了个实验,我分别启动了 旧provider新provider新consumer
此时双注册中心的服务

  • eureka
    • provider8081、provider8082
    • consumer8092
  • nacos
    • provider8082
    • consumer8092

现在我通过consumer8092客户端去请求,得到的结果只有 this is nacos-service ,因此判断注册中心默认走的是nacos.
因为走nacos只会返回this is nacos-service, nacos只有一个实例。
如果走eureka的话会轮询返回this is nacos-service、this is eureka-service ,eureka有两个实例。

  • 此时的流程图 虚线代表该线路空闲
    在这里插入图片描述

这里我找了下源码CompositeDiscoveryClient,调用的时候打了断点,发现系统创建了三个discoveryClientnacos排在第一个,如果可用的话直接就返回了 ,所以可以理解为默认走的是nacos在这里插入图片描述
这里我想到了nacos有个服务下线功能,如果我将nacos中的服务下线之后应该就会去走eureka了吧
在这里插入图片描述
等待几秒过后,通过consumer8092客户端去请求,得到了我想要的结果
分别轮询返回了 this is nacos-servicethis is eureka-service,证明已经走eureka了

  • 此时流程图虚线代表该线路空闲在这里插入图片描述

最后

此时我们生产上边是 新consumer、新provider、eureka、nacos,既然我们要切换到nacos,那eureka就也要停掉了,我们可以在下一版的服务中去掉 eureka的依赖和配置,只留下nacos,将这一个新版本部署上去之后就可以停掉eureka了

  • 如下图所示
    在这里插入图片描述

注意

如果直接引入eureka-client和nacos-client 会报错,如下

Field autoServiceRegistration in org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration required a single bean, but 2 were found:
	- nacosAutoServiceRegistration: defined by method 'nacosAutoServiceRegistration' in class path resource [com/alibaba/cloud/nacos/registry/NacosServiceRegistryAutoConfiguration.class]
	- eurekaAutoServiceRegistration: defined by method 'eurekaAutoServiceRegistration' in class path resource [org/springframework/cloud/netflix/eureka/EurekaClientAutoConfiguration.class]
  1. 需要在配置文件添加如下内容
spring.autoconfigure.exclude=org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration
  1. 启动类添加注解
@EnableConfigurationProperties(AutoServiceRegistrationProperties.class)

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转载自blog.csdn.net/weixin_43627706/article/details/125311609