高可用集群配置
当注册中心扛不住高并发的时候,这时候 要用集群来扛;
新建两个module microservice-eureka-server-2002 microservice-eureka-server-2003
1、pom.xml 依赖如下:
4.0.0
com.javachz
microservice
1.0-SNAPSHOT
microservice-eureka-server-2002
1.8
org.springframework.cloud
spring-cloud-starter-eureka-server
org.springframework.boot
spring-boot-starter-test
test
org.springframework.boot
spring-boot-maven-plugin
4.0.0
com.javachz
microservice
1.0-SNAPSHOT
microservice-eureka-server-2003
1.8
org.springframework.cloud
spring-cloud-starter-eureka-server
org.springframework.boot
spring-boot-starter-test
test
org.springframework.boot
spring-boot-maven-plugin
新创建的两个启动类EurekaServerApplication_2002,EurekaServerApplication_2003添加注解;
package com.javachz.microserviceeurekaserver2002;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@EnableEurekaServer
@SpringBootApplication
public class MicroserviceEurekaServer2002Application {
public static void main(String[] args) {
SpringApplication.run(MicroserviceEurekaServer2002Application.class, args);
}
}
package com.javachz.microserviceeurekaserver2003;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@EnableEurekaServer
@SpringBootApplication
public class MicroserviceEurekaServer2003Application {
public static void main(String[] args) {
SpringApplication.run(MicroserviceEurekaServer2003Application.class, args);
}
}
3、前面单机的时候 eureka注册中心实例名称 是localhost,现在是集群,不能三个实例都是localhost,这里复杂的办法是搞三个虚拟机,麻烦,这里有简单办法,直接配置本机hosts,来实现本机域名映射;
找到 C:\Windows\System32\drivers\etc 打开hosts,加配置
127.0.0.1 eureka2001.javaxl.com
127.0.0.1 eureka2002.javaxl.com
127.0.0.1 eureka2003.javaxl.com
4、修改三个项目的application.yml文件,主要是修改 hostname和defaultZone,
2001修改:
server:
port: 2001
context-path: /
eureka:
instance:
# 单机 hostname: localhost #eureka注册中心实例名称
hostname: eureka2001.javachz.com # 集群
client:
register-with-eureka: false #false 由于该应用为注册中心,所以设置为false,代表不向注册中心注册自己。
service-url:
defaultZone: http://eureka2002.javachz.com:2002/eureka/,http://eureka2003.javachz.com:2003/eureka/ # 集群
#单机defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/ #设置与Eureka注册中心交互的地址,查询服务和注册服务用到
2002修改:
server:
port: 2002
context-path: /
eureka:
instance:
# 单机 hostname: localhost #eureka注册中心实例名称
hostname: eureka2002.javachz.com # 集群
client:
register-with-eureka: false #false 由于该应用为注册中心,所以设置为false,代表不向注册中心注册自己。
service-url:
defaultZone: http://eureka2001.javachz.com:2001/eureka/,http://eureka2003.javachz.com:2003/eureka/ # 集群
#单机defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/ #设置与Eureka注册中心交互的地址,查询服务和注册服务用到
2003修改:
server:
port: 2003
context-path: /
eureka:
instance:
hostname: eureka2003.javachz.com
client:
register-with-eureka: false
service-url:
defaultZone: http://eureka2001.javachz.com:2001/eureka/,http://eureka2002.javachz.com:2002/eureka/
5、修改服务提供者项目的application.yml,主要修改eureka.client.service-url.defaultZone
server:
port: 1001
context-path: /
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/mysql?useUnicode=true&characterEncoding=UTF-8
username: root
password: 123456
eureka:
instance:
hostname: localhost
appname: microservice-student
instance-id: microservice-student:1001
prefer-ip-address: true
client:
service-url:
defaultZone: http://eureka2001.javachz.com:2001/eureka/,http://eureka2002.javachz.com:2002/eureka/,http://eureka2003.javachz.com:2003/eureka/
info:
groupId: com.javachz.testSpringcloud
artifactId: microservice-student-provider-1001
version: 1.0-SNAPSHOT
userName: http://javachz.com
phone: 123456
最后我们测试下:
启动三个注册中心,以及服务提供者项目;
然后浏览器地址栏输入:
http://localhost:2002/
http://eureka2001.javachz.com:2001/
http://eureka2002.javachz.com:2002/
http://eureka2003.javachz.com:2003/
上面eureka服务搭建,除了yml文件不一样,其他文件都一样,那么我们有什么办法能够将多个eureka服务集合到一个工程中去呢?
创建一个microservice-eureka-server(三合一)子工程
Pom依赖
4.0.0
com.javachz
microservice
1.0-SNAPSHOT
microservice-eureka-server
1.8
org.springframework.cloud
spring-cloud-starter-eureka-server
org.springframework.boot
spring-boot-starter-test
test
org.springframework.boot
spring-boot-maven-plugin
application.yml
---
server:
port: 2001
context-path: /
eureka:
instance:
hostname: eureka2001.javachz.com
client:
register-with-eureka: false
fetch-registry: false
service-url:
defaultZone: http://eureka2002.javachz.com:2002/eureka/,http://eureka2003.javachz.com:2003/eureka/
spring:
profiles: eureka2001
---
server:
port: 2002
context-path: /
eureka:
instance:
hostname: eureka2002.javachz.com
client:
register-with-eureka: false
fetch-registry: false
service-url:
defaultZone: http://eureka2001.javachz.com:2001/eureka/,http://eureka2003.javachz.com:2003/eureka/
spring:
profiles: eureka2002
---
server:
port: 2003
context-path: /
eureka:
instance:
hostname: eureka2003.javachz.com
client:
register-with-eureka: false
fetch-registry: false
service-url:
defaultZone: http://eureka2001.javachz.com:2001/eureka/,http://eureka2002.javachz.com:2002/eureka/
spring:
profiles: eureka2003
MicroserviceEurekaServerApplication
package com.javachz.microserviceeurekaserver;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@EnableEurekaServer
@SpringBootApplication
public class MicroserviceEurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(MicroserviceEurekaServerApplication.class, args);
}
}
开发环境,我们经常会遇到这个红色的警告;
当我们长时间为访问服务以及变更服务实例名称的时候,就会出现这个红色警告;
默认情况,如果服务注册中心再一段时间内没有接收到某个微服务实例的心跳,服务注册中心会注销该实例(默认90秒)。
由于正式环境,经常会有网络故障,网络延迟问题发生,服务和注册中心无法正常通信,此时服务是正常的,不应该注销该服务,Eureka这时候,就通过“自我保护模式”来解决问题,当短时间和服务失去通信时,保留服务信息,当恢复网络和通信时候,退出“自我保护模式”;
通过“自我保护模式”,使Eureka集群更加的健壮和稳定;