Eureka基础

1.Spring Cloud Eureka

1.基于Netfilx Eureka做了二次封装

2.由两个组件组成：

Eureka Server 注册中心：健康检查,心跳检测。

Eureka Client 服务注册：简化与服务器的交互。负载均衡。

3.客户端发现：Eureka
服务端发现：Nginx，Zookeeper，kubernetes

4.微服务特点异构：不同语言，不同数据库

5.服务拆分方法论：水平复制，数据分区，功能解耦

2.Eureka Server

记录所有应用信息的状态,是Eureka Server同时也是Eureka Client。

1.导入依赖

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

2.主类上加注解@EnableEurekaServer

3.配置yml

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8762/eureka/  #注册地址
    register-with-eureka: false  #是否向注册中心注册自己
  server:
    enable-self-preservation: false #关闭自我保护机制
spring:
  application:
    name: eureka

3.Eureka Client

1.导入依赖

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

2.启动类上加@EnableDiscoveryClient

3.配置yml

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/  #注册地址
  instance:
    hostname: clientName  #应用别名
spring:
  application:
    name: client #应用名字

4.Eureka的高可用

1.三个Eureka Server之间互相注册

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/

2.Eureka Client向三个Eureka Server注册

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/,http://localhost:8763/eureka/