2、eureka注册中心集群

1、 Eureka作为spring cloud的服务发现与注册中心，在整个的微服务体系中，处于核心位置。单机模式下的eureka服务，显然不能满足高可用的实际生产环境，这就要求配置一个能够应对各种突发情况，具有较强容灾能力的eureka服务。Eureka通过“伙伴机制”实现高可用。每一台Eureka都需要在配置中指定另外两个Eureka的地址伙伴，Eureka启动时会向自己的伙伴节点获取当前已经存在的注册表，这样在向Eureka集群中新加机器时就不需要担心注册表的不完整。

2、新建三个maven项目，分别为sc-eureka-cluster-server-node1，sc-eureka-cluster-server-node2，sc-eureka-cluster-server-node3。项目结构如下：

备注：pom.xml和EurekaServerApplication.java的内容给单机模式是一模一样的，请参考上篇文章。

3、主要看下bootstap.yml或者application.yml文件的改动

sc-eureka-cluster-server-node1

spring:

  application:

    name: sc-eureka-cluster-server-node1

   

server:

  port: 5001

 

eureka:

  instance:

    hostname: sc-eureka-cluster-server-node1

    lease-renewal-interval-in-seconds: 30

    lease-expiration-duration-in-seconds: 30

    prefer-ip-address: true

  client:

    registerWithEureka: false

    fetchRegistry: false

    serviceUrl:

      defaultZone: http://sc-eureka-cluster-server-node2:5002/eureka/,http://sc-eureka-cluster-server-node3:5003/eureka/

sc-eureka-cluster-server-node2

spring:

  application:

    name: sc-eureka-cluster-server-node2

   

server:

  port: 5002

 

eureka:

  instance:

    hostname: sc-eureka-cluster-server-node2

    lease-renewal-interval-in-seconds: 30

    lease-expiration-duration-in-seconds: 30

    prefer-ip-address: true

  client:

    registerWithEureka: false

    fetchRegistry: false

    serviceUrl:

      defaultZone: http://sc-eureka-cluster-server-node1:5001/eureka/,http://sc-eureka-cluster-server-node3:5003/eureka/

sc-eureka-cluster-server-node3

spring:

  application:

    name: sc-eureka-cluster-server-node3

   

server:

  port: 5003

 

eureka:

  instance:

    hostname: sc-eureka-cluster-server-node3

    lease-renewal-interval-in-seconds: 30

    lease-expiration-duration-in-seconds: 30

    prefer-ip-address: true

  client:

    registerWithEureka: false

    fetchRegistry: false

    serviceUrl:

      defaultZone: http://sc-eureka-cluster-server-node1:5001/eureka/,http://sc-eureka-cluster-server-node2:5001/eureka/