1 Eureka

1.1 Eureka 服务注册中心

怎么完成服务注册中心的搭建

依赖引入

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.6.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Finchley.SR2</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

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

添加注解

@EnableEurekaServer

application.properties配置

spring.application.name=eureka-server
server.port=8761

#不向注册中心注册自己
eureka.client.register-with-eureka=false
#维护服务实例,不检索服务
eureka.client.fetch-registry=false

访问

http://localhost:8761/

1.2 Eureka 服务客户端

怎么注册客户端到Eureka注册中心

依赖引入

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.6.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Finchley.SR2</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

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

添加注解

@EnableDiscoveryClient

application.properties配置

spring.application.name=eureka-client-user-service
server.port=8083

eureka.client.serviceUrl.defaultZone=http://hello:123456@localhost:8761/eureka/
eureka.instance.preferIpAddress=true
eureka.instance.instance-id=${spring.application.name}:${spring.cloud.client.ip-address}:${server.port}

1.3 Eureka高可用

1）为什么要搭建高可用Eureka

解决某个Eureka挂掉后，保证仍然可以使用

2）如何配置高可用

以两个Eureka实例为例

master

application-master.properties配置

server.port=8761

eureka.client.serviceUrl.defaultZone=http://hello:123456@localhost:8762/eureka/

slaveone

application-slaveone.properties配置

server.port=8762

eureka.client.serviceUrl.defaultZone=http://hello:123456@localhost:8761/eureka/

3）测试

启动两个实例，再启动eureka-client-user-service和eureka-client-article-service

Eureka 8761

Eureka 8762

停止Eureka 8761，访问接口http://localhost:8082/article/callHello2