springCloud搭建微服务集群+Zuul服务器端负载均衡

实现
Eureka集群（eurekaServer）：8001、8002、8003
服务提供方（eurekaClient）：9001、9002
服务端负载均衡服务：9100

1、新建工程eureka服务器，用idea创建springboot项目，引入eureka依赖

下面是三台服务器的配置文件

//第一台
server:
  port: 8001

spring:
  application:
    name: eureka-server

eureka:
  server:
    use-read-only-response-cache: false  #禁用readOnlyMap，分为ReadWriteMap和ReadOnlyMap
    eviction-interval-timer-in-ms: 3000  #主动失效检测时间
  instance:
    hostname: server8001
  client:
#    register-with-eureka: false  #false表示不将自己也作为服务注册到eureka
#    fetch-registry: false
    service-url:
      #集群设置，搭建eureka集群,用逗号分隔
      defaultZone: http://localhost:8002/eureka/,http://localhost:8003/eureka/

//第二台
server:
  port: 8002

spring:
  application:
    name: eureka-server

eureka:
  server:
    use-read-only-response-cache: false
    eviction-interval-timer-in-ms: 3000
  instance:
    hostname: server8002
  client:
#    register-with-eureka: false #表示不将自己作为服务注册进eureka
#    fetch-registry: false
    service-url:
      #集群设置，搭建eureka集群,用逗号分隔，defaultZone是map类型，所以没有提示
      defaultZone: http://localhost:8001/eureka/,http://localhost:8003/eureka/

//第三台
server:
  port: 8003

spring:
  application:
    name: eureka-server

eureka:
  server:
    use-read-only-response-cache: false
    eviction-interval-timer-in-ms: 3000
  instance:
    hostname: server8003
  client:
#    register-with-eureka: false #表示不将自己作为服务注册进eureka
#    fetch-registry: false
    service-url:
      #集群设置，搭建eureka集群,用逗号分隔，defaultZone是map类型，所以没有提示
      defaultZone: http://localhost:8001/eureka/,http://localhost:8002/eureka/

//第一台
server:
  port: 9001

spring:
  application:
    name: eureka-client

eureka:
  client:
    service-url:
      # 指定集群服务器列表
      defaultZone: http://localhost:8001/eureka/,http://localhost:8002/eureka/,http://localhost:8003/eureka/
  instance:
    instance-id: client9001.com
    prefer-ip-address: true
    lease-renewal-interval-in-seconds: 5       #发送心跳包服务刷新时间
    lease-expiration-duration-in-seconds: 15  #服务过期时间

//第二台
server:
  port: 9002
spring:
  application:
    name: eureka-client

eureka:
  client:
    service-url:
      # 指定集群服务器列表
      defaultZone: http://localhost:8001/eureka/
  instance:
    instance-id: client9002.com
    prefer-ip-address: true
    lease-renewal-interval-in-seconds: 5       #发送心跳包服务刷新时间
    lease-expiration-duration-in-seconds: 15  #服务过期时间

添加EnableEurekaClient注解，并添加api业务测试接口

 
3、zuul负载均衡服务

server:
  port: 9100

spring:
  application:
    name: zuul-gateway

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8001/eureka,http://localhost:8002/eureka,http://localhost:8003/eureka
    registry-fetch-interval-seconds: 5  #拉取服务列表时间
  instance:
    instance-id: gateway-9100.com
    prefer-ip-address: true

zuul:
  prefix: /gateway
  ignored-services: eureka-client
  routes:
    eureka-client.serviceId: eureka-client
    eureka-client.path: /client/**

 依次启动Eureka服务器、服务提供者client，zull服务，访问其中一台Eureka服务器的控制台显示如下

 不停刷新页面，会在9001和9002之间切换，证明配置成功，关闭9002应用，刷新页面，刚开始还会出现访问失败，过了一段时间后就稳定了，
会有一个时间差，也可以给zuul配置熔断器来进行服务降级或者转发请求到其他正常服务。