SpringCloud 学习(3)：eureka集群

小灰灰 2020-11-15 15:28 685阅读 0赞

> # SpringCloud 学习(3)：eureka集群 #

##### \*这篇文章基于上篇文章进行修改，黄色背景为修改的部分。  #####

#### 1.介绍：Eureka集群就是n个Eureka服务器+n个Eureka客户端，目的是实现负载均衡，减轻单个服务器的压力。 ####

#### 2.原理： ####

![70][]

#### 3.代码实现  ####

*  Eureka服务器(建立项目consultingPlatform\_server):  
    1).pom.xml

<parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.13.RELEASE</version>
        </parent>
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>Edgware.SR3</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-config</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
            </dependency>
        </dependencies>

2） .application.properties （我们通过profiles指定不同的配置文件，模拟不同的服务器）|

spring.profiles.active=server1
    #spring.profiles.active=server2

.application-server1.properties

server.port=1001
    #服务名称
    spring.application.name=server
    #eureka服务器路径
    eureka.client.service-url.defaultZone=http://localhost:1002/eureka/

.application-server2.properties

server.port=1002
    #服务名称
    spring.application.name=server
    #eureka服务器路径
    eureka.client.service-url.defaultZone=http://localhost:1001/eureka/

在这里两台Eureka服务器互相注册。。ok,到这里Eureka集群服务器已经搭建完毕，通过修改profiles分别启动两个Eureka服务器。  
  
  
3).Application.java(启动类)

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.builder.SpringApplicationBuilder;
    import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
    
     
    @SpringBootApplication
    @EnableEurekaServer
    public class Application {
        public static void main(String[] args) {
            new SpringApplicationBuilder(Application.class).web(true).run(args);
        }
    }

*  服务提供者（创建项目police\_client）

1）.pom.xml

<parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.13.RELEASE</version>
        </parent>
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>Edgware.SR3</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-config</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka</artifactId>
            </dependency>
        </dependencies>

2） .application.properties（我们通过profiles指定不同的配置文件，模拟不同的客户端）

spring.profiles.active=client1
    
    #spring.profiles.active=client2

.application-client1.properties

server.port=2001
    #服务名称
    spring.application.name=police
    #eureka服务器路径
    eureka.client.service-url.defaultZone=http://localhost:1001/eureka/,http://localhost:1002/eureka/

.application-client2.properties

server.port=2002
    #服务名称
    spring.application.name=police
    #eureka服务器路径
    eureka.client.service-url.defaultZone=http://localhost:1001/eureka/,http://localhost/eureka/

3 ).Application.java

import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.builder.SpringApplicationBuilder;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    
    /**
     * @author: lqh
     * @description:
     * @program: police_client
     * @create: 2018-06-06 11:50
     **/
    @SpringBootApplication
    @EnableEurekaClient
    public class Application {
        public static void main(String[] args) {
            new SpringApplicationBuilder(Application.class).web(true).run(args);
        }
    }

4 ). PoliceController.java

import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    /**
     * @author: 
     * @description:
     * @program: police_client
     * @create: 2018-06-06 11:59
     **/
    @RestController
    public class PoliceController {
        @RequestMapping("call")
        public String call(HttpServletRequest request) {
            //这里返回url,便于查看服务提供者。
            return "call:" + request.getRequestURL().toString();
        }
    }

*  服务调用者(创建项目people\_caller)：

*  1).pom.xml  
    
    
        <parent>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-parent</artifactId>
                <version>1.5.13.RELEASE</version>
            </parent>
            <dependencyManagement>
                <dependencies>
                    <dependency>
                        <groupId>org.springframework.cloud</groupId>
                        <artifactId>spring-cloud-dependencies</artifactId>
                        <version>Edgware.SR3</version>
                        <type>pom</type>
                        <scope>import</scope>
                    </dependency>
                </dependencies>
            </dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-starter-config</artifactId>
                </dependency>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-starter-eureka</artifactId>
                </dependency>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
                </dependency>
            </dependencies>
    
    2.application.properties  
    
    
        server.port=6003
        
        #服务名称
        spring.application.name=people
        #注册路径
        eureka.client.service-url.defaultZone=http://localhost:6001/eureka/
    
    3.Application  
    
    
        import org.springframework.boot.autoconfigure.SpringBootApplication;
        import org.springframework.boot.builder.SpringApplicationBuilder;
        import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
        
        @SpringBootApplication
        @EnableEurekaClient
        public class Application {
            public static void main(String[] args) {
                new SpringApplicationBuilder(Application.class).web(true).run(args);
            }
        }
    
      
    4.PeopleController  
    
    
        import org.springframework.cloud.client.loadbalancer.LoadBalanced;
        import org.springframework.context.annotation.Bean;
        import org.springframework.context.annotation.Configuration;
        import org.springframework.web.bind.annotation.RequestMapping;
        import org.springframework.web.bind.annotation.RestController;
        import org.springframework.web.client.RestTemplate;
        
         
        @Configuration
        @RestController
        public class PeopleController {
        
            @Bean
            @LoadBalanced
            RestTemplate getRestTemplate() {
                return new RestTemplate();
            }
        
            @RequestMapping("call")
            public String call() {
                return getRestTemplate().getForObject("http://police/call",String.class);
            }
        }
    
      
    OK,跑起来。。

####  ####

*  \#图一：可以看到有2个服务器，2个服务提供者，1个服务调用者

*  ![2018061015370276][]

*  \#图二：可以看到有2个服务器，2个服务提供者，1个服务调用者

![20180610153709744][]

*  \#图三：服务调用者，可以看到端口一直在2001\\2002之间切换，说明一直在调用不同的服务提供者。

![20180610153717520][]

[70]: /images/1605454097967.png
[2018061015370276]: /images/1605454071119.png
[20180610153709744]: /images/1605454048076.png
[20180610153717520]: /images/1605454010042.png