Spring Cloud Eureka动态扩容

胖虎

发布于 2019-06-26 17:09:25

1.5K0

发布于 2019-06-26 17:09:25

文章被收录于专栏：晏霖

前言本文心得包括案例基于《重新定义》，动态扩容Eureka是为了不影响已运行服务的情况下进行扩容。

正文利用了config进行统一管理了eureka服务的配置，首先创建一个父module，主要就是把web工程依赖的jar包含在内，pom如下

<groupId>cn.springcloud.book</groupId>
    <artifactId>ch3-1</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>pom</packaging>

    <name>ch3-1</name>
    <description>ch3-1</description>

    <modules>
        <module>ch3-1-config-server</module>
        <module>ch3-1-eureka-server</module>
        <module>ch3-1-eureka-client</module>
    </modules>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.RELEASE</spring-cloud.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <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>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

然后在这个父module下创建ConfigServer 名为：ch3-1-config-server，pom如下

<parent>
        <groupId>cn.springcloud.book</groupId>
        <artifactId>ch3-1</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
        </dependency>
    </dependencies>

当前configserver的main方法及配置文件

@SpringBootApplication
@EnableConfigServer
public class Ch31ConfigServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(Ch31ConfigServerApplication.class, args);
    }
}

spring:
  application:
    name: config-server
  profiles:
    active: native
server:
  port: 8888

在resources下创建一个目录叫 config，里面创建三个yml文件，这里为了方便，我建了三个配置文件。代码如下

第一个是eureka的客户端配置文件

server:
  port: 8081

spring:
  application:
    name: eureka-client1

eureka:
  client:
    serviceUrl:
#      defaultZone: http://localhost:8761/eureka/ # one eureka server
#      defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/ # two eureka server
      defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/,http://localhost:8763/eureka/ # three eureka server

第二个是eureka服务的peer1文件

server:
  port: 8761

spring:
  application:
    name: eureka-server
eureka:
  instance:
    hostname: localhost
    preferIpAddress: true
  client:
    registerWithEureka: true
    fetchRegistry: true
    serviceUrl:
#      defaultZone: http://localhost:8761/eureka/ # one eureka server
#      defaultZone: http://localhost:8762/eureka/ # two eureka server
      defaultZone: http://localhost:8762/eureka/,http://localhost:8763/eureka/ # three eureka server
  server:
      waitTimeInMsWhenSyncEmpty: 0
      enableSelfPreservation: false

第三个是eureka服务的peer2文件

server:
  port: 8762

eureka:
  instance:
    hostname: localhost
    preferIpAddress: true
  client:
    registerWithEureka: true
    fetchRegistry: true
    serviceUrl:
#      defaultZone: http://localhost:8761/eureka/ # two eureka server
      defaultZone: http://localhost:8761/eureka/,http://localhost:8763/eureka/ # three eureka server
  server:
      waitTimeInMsWhenSyncEmpty: 0
      enableSelfPreservation: false

创建EurekaServer 工程名：ch3-1-eureka-server

pom文件

<groupId>cn.springcloud.book</groupId>
    <artifactId>ch3-1-eureka-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>ch3-1-eureka-server</name>
    <description>ch3-1-eureka-server</description>

    <parent>
        <groupId>cn.springcloud.book</groupId>
        <artifactId>ch3-1</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
    </dependencies>

eureka服务的两个配置文件如下，分别是bootstrap.yml 和application.yml

spring:
  application:
    name: eureka-server
  cloud:
    config:
      uri: http://localhost:8888
management:
  endpoints:
    web:
      exposure:
        include: '*'
eureka:
  server:
    peer-eureka-nodes-update-interval-ms: 10000 #默认是10分钟即600000，

这里为了验证改为10秒 main方法启动类

@SpringBootApplication
@EnableEurekaServer
public class Ch31EurekaServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(Ch31EurekaServerApplication.class, args);
    }
}

最后一个就是创建eurakaClient

他的配置文件和eureka服务的两个配置文件都一样分别是bootstrap.yml 和application.yml ，区别是

spring:
  application:
    name: eureka-client

eurekaClient 的启动类

@SpringBootApplication
@EnableDiscoveryClient
public class Ch31EurekaClientApplication {

    public static void main(String[] args) {
        SpringApplication.run(Ch31EurekaClientApplication.class, args);
    }
}

现在所有代码都准备好了，我们来首先启动configServer

然后，下面的操作很关键，大家一定跟上，我会说的很清楚的