Spring Cloud Eureka

一、Eureka Client

1. 添加Eureka Client依赖

eureka client的group ID为org.springframework.cloud，artifact ID为spring-cloud-starter-netflix-eureka-client
例如：

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

2. 启用Eureka Client

1. 添加注解 @EnableEurekaClient/@EnableDiscoveryClient （不加也可以正常运行）
2. 配置application.yml文件

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

Tips:
@EnableEurekaClient和@EnableDiscoveryClient的区别：
@EnableDiscoveryClient该注解可以被其他注册中心扫描，然而@EnableEurekaClient只能被Eureka扫描

二、Eureka Server

1. 添加Eureka Server依赖

eureka client的group ID为org.springframework.cloud，artifact ID为spring-cloud-starter-netflix-eureka-server
例如：

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

2. 启用Eureka Server

1. 添加注解 @EnableEurekaServer
2. 配置application.yml文件

eureka:
  client:
    service-url: 
      defaultZone: http://localhost:8761/eureka/
    register-with-eureka: false

Eureka高可用

启用三个Eureka Server服务，互相注册到对方
例如：

---
spring:
  application:
    name: eureka
  profiles: server1
server:
  port: 8001
eureka:
  instance:
    hostname: server1
    prefer-ip-address: false
  client:
    service-url: 
      defaultZone: http://server2:8002/eureka/,http://server3:8003/eureka/

---
spring:
  application:
    name: eureka
  profiles: server2
server:
  port: 8002
eureka:
  instance:
    hostname: server2
    prefer-ip-address: false
  client:
    service-url:
      defaultZone: http://server1:8001/eureka/,http://server3:8003/eureka/

---
spring:
  application:
    name: eureka
  profiles: server3
server:
  port: 8003
eureka:
  instance:
    hostname: server3
    prefer-ip-address: false
  client:
    service-url:
      defaultZone: http://server1:8001/eureka/,http://server2:8002/eureka/

Tips:
server1、server2、server3分别对应三台主机，同一台机器测试时，需要修改本地host文件

127.0.0.1   server1
127.0.0.1   server2
127.0.0.1   server3