Eureka集群搭建

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；

提示：部分内容请前往上篇博客查找

普通操作

我们再新建两个module  microservice-eureka-server-2002  microservice-eureka-server-2003

1、pom.xml 把依赖加下；

microservice-eureka-server-2002

 

 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.yuan</groupId>
 7         <artifactId>t226microservice</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 
16     <dependencies>
17         <dependency>
18             <groupId>org.springframework.cloud</groupId>
19             <artifactId>spring-cloud-starter-eureka-server</artifactId>
20         </dependency>
21         <dependency>
22             <groupId>org.springframework.boot</groupId>
23             <artifactId>spring-boot-starter-test</artifactId>
24             <scope>test</scope>
25         </dependency>
26         <!--&lt;!&ndash;  修改后立即生效，热部署  &ndash;&gt;-->
27         <dependency>
28             <groupId>org.springframework</groupId>
29             <artifactId>springloaded</artifactId>
30         </dependency>
31         <dependency>
32             <groupId>org.springframework.boot</groupId>
33             <artifactId>spring-boot-devtools</artifactId>
34         </dependency>
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 
45 </project>

 

 

microservice-eureka-server-2003

 

 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.yuan</groupId>
 7         <artifactId>t226microservice</artifactId>
 8         <version>1.0-SNAPSHOT</version>
 9     </parent>
10     <artifactId>microservice-eureka-server-2003</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         <!--&lt;!&ndash;  修改后立即生效，热部署  &ndash;&gt;-->
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     </dependencies>
35     <build>
36         <plugins>
37             <plugin>
38                 <groupId>org.springframework.boot</groupId>
39                 <artifactId>spring-boot-maven-plugin</artifactId>
40             </plugin>
41         </plugins>
42     </build>
43 
44 </project>

 

 

 

2、2002  2003的主启动类EurekaServerApplication_2002，EurekaServerApplication_2003修改下；

MicroserviceEurekaServer2002Application

 1 package com.yuan.microserviceeurekaserver2002;
 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 MicroserviceEurekaServer2002Application {
10 
11     public static void main(String[] args) {
12         SpringApplication.run(MicroserviceEurekaServer2002Application.class, args);
13     }
14 
15 }

MicroserviceEurekaServer2003Application

 1 package com.yuan.microserviceeurekaserver2003;
 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 MicroserviceEurekaServer2003Application {
10 
11     public static void main(String[] args) {
12         SpringApplication.run(MicroserviceEurekaServer2003Application.class, args);
13     }
14 
15 }

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 

 

修改配置

 

127.0.0.1  eureka2001.yuan.com
127.0.0.1  eureka2002.yuan.com
127.0.0.1  eureka2003.yuan.com

 

4、修改三个项目的application.yml文件，主要是修改 hostname和defaultZone，

2001修改：

 1 server:
 2   port: 2001
 3   context-path: /
 4 eureka:
 5   instance:
 6     # 单机 hostname: localhost #eureka注册中心实例名称
 7     hostname: eureka2001.yuan.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。
11     service-url:
12       defaultZone: http://eureka2002.yuan.com:2002/eureka/,http://eureka2003.yuan.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修改：

 1 server:
 2   port: 2002
 3   context-path: /
 4 eureka:
 5   instance:
 6     hostname: eureka2002.yuan.com
 7   client:
 8     register-with-eureka: false
 9     service-url:
10       defaultZone: http://eureka2001.yuan.com:2001/eureka/,http://eureka2003.yuan.com:2003/eureka/

2003修改：

 1 server:
 2   port: 2003
 3   context-path: /
 4 eureka:
 5   instance:
 6     hostname: eureka2003.yuan.com
 7   client:
 8     register-with-eureka: false
 9     service-url:
10       defaultZone: http://eureka2001.yuan.com:2001/eureka/,http://eureka2002.yuan.com:2002/eureka/

完了之后一次启动：2001==》2002==》2003==》==》1001==》81

 

访问eureka2001.yuan.com:2001

 

访问eureka2002.yuan.com:2002

 

访问eureka2003.yuan.com:2003

 

消费端localhost:81/student/list

 

 

 

“骚操作”

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

 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.yuan</groupId>
 7         <artifactId>t226microservice</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         <dependency>
22             <groupId>org.springframework.boot</groupId>
23             <artifactId>spring-boot-starter-test</artifactId>
24             <scope>test</scope>
25         </dependency>
26         <!--&lt;!&ndash;  修改后立即生效，热部署  &ndash;&gt;-->
27         <dependency>
28             <groupId>org.springframework</groupId>
29             <artifactId>springloaded</artifactId>
30         </dependency>
31         <dependency>
32             <groupId>org.springframework.boot</groupId>
33             <artifactId>spring-boot-devtools</artifactId>
34         </dependency>
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 
45 </project>

修改yml文件

 1 ---
 2 server:
 3   port: 2001
 4   context-path: /
 5 eureka:
 6   instance:
 7     hostname: eureka2001.yuan.com
 8   client:
 9     register-with-eureka: false
10     service-url:
11       defaultZone: http://eureka2002.yuan.com:2002/eureka/,http://eureka2003.yuan.com:2003/eureka/
12 spring:
13   profiles: eureka2001
14 ---
15 server:
16   port: 2002
17   context-path: /
18 eureka:
19   instance:
20     hostname: eureka2002.yuan.com
21   client:
22     register-with-eureka: false
23     service-url:
24       defaultZone: http://eureka2001.yuan.com:2001/eureka/,http://eureka2003.yuan.com:2003/eureka/
25 spring:
26   profiles: eureka2002
27 ---
28 server:
29   port: 2003
30   context-path: /
31 eureka:
32   instance:
33     hostname: eureka2003.yuan.com
34   client:
35     register-with-eureka: false
36     service-url:
37       defaultZone: http://eureka2001.yuan.com:2001/eureka/,http://eureka2002.yuan.com:2002/eureka/
38 spring:
39   profiles: eureka2003

修改运行配置

1、选择Eureka2001ServerApplication，点击最左上角复制按钮然后进行下一步操作==》

2、将用红线划中的地方修改

         如右边第一处：Eureka2001ServerApplication

　　 第二处：同样

　　第三处：eureka2001

 

 启动顺序：2001》2002》2003》1001》81

 访问结果：  其他所有运行结果同上次是一样的，就不一一演示

 

 

 

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；

 

谢谢观看！！！

 

【推广】 免费学中医，健康全家人
原文地址：https://www.cnblogs.com/ly-0919/p/11996514.html