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
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
- 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
- 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:18335844494@163.com
* @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
- 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:18335844494@163.com
* @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:18335844494@163.com
* @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:18335844494@163.com
* @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
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
第一阶段流程图
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:18335844494@163.com
* @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:18335844494@163.com
* @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:18335844494@163.com
* @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:18335844494@163.com
* @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
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
eureka
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
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
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!
上线双注册双订阅新consumer服务,下线旧consumer
启动nacoConsumerApplication
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
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discoveryClient
,nacos
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
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
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-service
、this is eureka-service
,证明已经走eureka了
此时流程图
虚线代表该线路空闲
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
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]
- 需要在配置文件添加如下内容
spring.autoconfigure.exclude=org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration
- 启动类添加注解
@EnableConfigurationProperties(AutoServiceRegistrationProperties.class)
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