Eureka集群搭建
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;
普通操作
新建两个stringboot项目
module microservice-eureka-server-2002 microservice-eureka-server-2003
配置
microservice-eureka-server-2002
microservice-eureka-server-2003
pom.xml 依赖:
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> 4 <modelVersion>4.0.0</modelVersion> 5 <parent> 6 <groupId>com.javaqi</groupId> 7 <artifactId>qimicroservice</artifactId> 8 <version>1.0-SNAPSHOT</version> 9 </parent> 10 <artifactId>microservice-eureka-server-2002</artifactId> 11 12 <properties> 13 <java.version>1.8</java.version> 14 </properties> 15 <dependencies> 16 <dependency> 17 <groupId>org.springframework.cloud</groupId> 18 <artifactId>spring-cloud-starter-eureka-server</artifactId> 19 </dependency> 20 <dependency> 21 <groupId>org.springframework.boot</groupId> 22 <artifactId>spring-boot-starter-test</artifactId> 23 <scope>test</scope> 24 </dependency> 25 <!-- 修改后立即生效,热部署 --> 26 <dependency> 27 <groupId>org.springframework</groupId> 28 <artifactId>springloaded</artifactId> 29 </dependency> 30 <dependency> 31 <groupId>org.springframework.boot</groupId> 32 <artifactId>spring-boot-devtools</artifactId> 33 </dependency> 34 35 </dependencies> 36 <build> 37 <plugins> 38 <plugin> 39 <groupId>org.springframework.boot</groupId> 40 <artifactId>spring-boot-maven-plugin</artifactId> 41 </plugin> 42 </plugins> 43 </build> 44 </project>
添加主启动类EurekaServerApplication_2002,EurekaServerApplication_2003注解
@EnableEurekaServer
@SpringBootApplication
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:WindowsSystem32driversetc 打开hosts,加配置
修改application.yml文件,主要是修改 hostname和defaultZone,
2001
1 server: 2 port: 2001 3 context-path: / 4 5 eureka: 6 instance: 7 # 单机 hostname: localhost #eureka注册中心实例名称 8 hostname: eureka2001.javaqi.com # 集群 9 client: 10 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。 11 service-url: 12 defaultZone: http://eureka2002.javaqi.com:2002/eureka/,http://eureka2003.javaqi.com:2003/eureka/ # 集群 13 #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
1 server: 2 port: 2002 3 context-path: / 4 eureka: 5 instance: 6 # 单机 hostname: localhost #eureka注册中心实例名称 7 hostname: eureka2002.javaqi.com # 集群 8 client: 9 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。 10 service-url: 11 defaultZone: http://eureka2001.javaqi.com:2001/eureka/,http://eureka2003.javaqi.com:2003/eureka/ # 集群 12 #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
1 server: 2 port: 2003 3 context-path: / 4 eureka: 5 instance: 6 # 单机 hostname: localhost #eureka注册中心实例名称 7 hostname: eureka2003.javaqi.com # 集群 8 client: 9 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。 10 service-url: 11 defaultZone: http://eureka2001.javaqi.com:2001/eureka/,http://eureka2002.javaqi.com:2002/eureka/ # 集群 12 #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
修改服务提供者项目的application.yml,主要修改eureka.client.service-url.defaultZone
1 server: 2 port: 2001 3 context-path: / 4 eureka: 5 instance: 6 hostname: eureka2001.javaqi.com 7 client: 8 register-with-eureka: false 9 service-url: 10 defaultZone: http://eureka2002.javaqi.com:2002/eureka/,http://eureka2003.javaqi.com:2003/eureka/ # 集群
启动三个注册中心,以及服务提供者项目;
浏览器地址栏访问
骚操作
删除之前的三个项目
创建一个microservice-eureka-server(三合一)子工程
配置pom
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> 4 <modelVersion>4.0.0</modelVersion> 5 <parent> 6 <groupId>com.javaqi</groupId> 7 <artifactId>qimicroservice</artifactId> 8 <version>1.0-SNAPSHOT</version> 9 </parent> 10 <artifactId>microservice-eureka-server</artifactId> 11 12 <properties> 13 <java.version>1.8</java.version> 14 </properties> 15 16 <dependencies> 17 <dependency> 18 <groupId>org.springframework.cloud</groupId> 19 <artifactId>spring-cloud-starter-eureka-server</artifactId> 20 </dependency> 21 22 <dependency> 23 <groupId>org.springframework.boot</groupId> 24 <artifactId>spring-boot-starter-test</artifactId> 25 <scope>test</scope> 26 </dependency> 27 28 <!-- 修改后立即生效,热部署 --> 29 <dependency> 30 <groupId>org.springframework</groupId> 31 <artifactId>springloaded</artifactId> 32 </dependency> 33 34 <dependency> 35 <groupId>org.springframework.boot</groupId> 36 <artifactId>spring-boot-devtools</artifactId> 37 </dependency> 38 </dependencies> 39 40 <build> 41 <plugins> 42 <plugin> 43 <groupId>org.springframework.boot</groupId> 44 <artifactId>spring-boot-maven-plugin</artifactId> 45 </plugin> 46 </plugins> 47 </build> 48 49 50 </project>
Yml文件
1 --- 2 server: 3 port: 2001 4 context-path: / 5 eureka: 6 instance: 7 hostname: eureka2001.javaqi.com 8 client: 9 register-with-eureka: false 10 service-url: 11 defaultZone: http://eureka2002.javaqi.com:2002/eureka/,http://eureka2003.javaqi.com:2003/eureka/ 12 spring: 13 profiles: eureka2001 14 --- 15 server: 16 port: 2002 17 context-path: / 18 eureka: 19 instance: 20 hostname: eureka2002.javaqi.com 21 client: 22 register-with-eureka: false 23 service-url: 24 defaultZone: http://eureka2001.javaqi.com:2001/eureka/,http://eureka2003.javaqi.com:2003/eureka/ 25 spring: 26 profiles: eureka2002 27 --- 28 server: 29 port: 2003 30 context-path: / 31 eureka: 32 instance: 33 hostname: eureka2003.javaqi.com 34 client: 35 register-with-eureka: false 36 service-url: 37 defaultZone: http://eureka2001.javaqi.com:2001/eureka/,http://eureka2002.javaqi.com:2002/eureka/ 38 spring: 39 profiles: eureka2003
启动类MicroserviceEurekaServerApplication.java
1 package com.javaqi.microserviceeurekaserver; 2 3 import org.springframework.boot.SpringApplication; 4 import org.springframework.boot.autoconfigure.SpringBootApplication; 5 import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer; 6 7 @EnableEurekaServer 8 @SpringBootApplication 9 public class MicroserviceEurekaServerApplication { 10 11 public static void main(String[] args) { 12 SpringApplication.run(MicroserviceEurekaServerApplication.class, args); 13 } 14 15 }
配置
效果跟普通操作的效果是一致的
Eureka自我保护机制
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;