SpringCloud

Posted 2022-12-30 tubewang

搭建Eureka注册中心

一、环境搭建

 

 

 

 

 

 

 

 

 pom.xml文件分析：

 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>org.springframework.boot</groupId>
 7         <artifactId>spring-boot-starter-parent</artifactId>
 8         <version>2.1.9.RELEASE</version>
 9         <relativePath/> <!-- lookup parent from repository -->
10     </parent>
11     <groupId>com.angei</groupId>
12     <artifactId>eurekaserver</artifactId>
13     <version>0.0.1-SNAPSHOT</version>
14     <name>eurekaserver</name>
15     <description>Demo project for Spring Boot</description>
16 
17     <properties>
18         <java.version>1.8</java.version>
19         <spring-cloud.version>Greenwich.SR3</spring-cloud.version>
20     </properties>
21 
22     <dependencies>
23         <dependency>
24             <groupId>org.springframework.cloud</groupId>
25             <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
26         </dependency>
27 
28         <dependency>
29             <groupId>org.springframework.boot</groupId>
30             <artifactId>spring-boot-starter-test</artifactId>
31             <scope>test</scope>
32         </dependency>
33     </dependencies>
34 
35     <dependencyManagement>
36         <dependencies>
37             <dependency>
38                 <groupId>org.springframework.cloud</groupId>
39                 <artifactId>spring-cloud-dependencies</artifactId>
40                 <version>$spring-cloud.version</version>
41                 <type>pom</type>
42                 <scope>import</scope>
43             </dependency>
44         </dependencies>
45     </dependencyManagement>
46 
47     <build>
48         <plugins>
49             <plugin>
50                 <groupId>org.springframework.boot</groupId>
51                 <artifactId>spring-boot-maven-plugin</artifactId>
52             </plugin>
53         </plugins>
54     </build>
55 
56 </project>

如果下载失败，可以在pom.xml中添加如下配置，使其从国内阿里云镜像中下载相关内容。

1     <repositories>
2         <repository>
3             <id>aliyun</id>    
4         <name>aliyun</name>    
5         <url>https://maven.aliyun.com/repository/public</url>    
6     </repository>    
7     </repositories>

添加application.yml

 1 server:
 2   port: 8761
 3 eureka:
 4   instance:
 5     appname: provider-service
 6     hostname: localhost
 7   client:
 8     service-url:
 9       defaultZone:
10         http://localhost:8761/eureka/
11     register-with-eureka: false
12     fetch-registry: false

在EurekaserverApplication.java中添加如下标签：@EnableEurekaServer

 

 运行：

 

开发Eureka客户端(微服务)

Eureka客户端开发要点
   ◆maven 依赖 spring-cloud-starter-netflix-eureka-client
   ◆application.yml 配置 eureka.client.service-url.defaultZone
   ◆入口类増加 @EnableEurekaClient

 

 

 

 

 

 pom.xml

 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>org.springframework.boot</groupId>
 7         <artifactId>spring-boot-starter-parent</artifactId>
 8         <version>2.1.9.RELEASE</version>
 9         <relativePath/> <!-- lookup parent from repository -->
10     </parent>
11     <groupId>com.angei</groupId>
12     <artifactId>eureka-client</artifactId>
13     <version>0.0.1-SNAPSHOT</version>
14     <name>eureka-client</name>
15     <description>Demo project for Spring Boot</description>
16 
17     <properties>
18         <java.version>1.8</java.version>
19         <spring-cloud.version>Greenwich.SR3</spring-cloud.version>
20     </properties>
21 
22     <dependencies>
23         <dependency>
24             <groupId>org.springframework.boot</groupId>
25             <artifactId>spring-boot-starter-web</artifactId>
26         </dependency>
27         <dependency>
28             <groupId>org.springframework.cloud</groupId>
29             <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
30         </dependency>
31 
32         <dependency>
33             <groupId>org.springframework.boot</groupId>
34             <artifactId>spring-boot-starter-test</artifactId>
35             <scope>test</scope>
36         </dependency>
37     </dependencies>
38 
39     <dependencyManagement>
40         <dependencies>
41             <dependency>
42                 <groupId>org.springframework.cloud</groupId>
43                 <artifactId>spring-cloud-dependencies</artifactId>
44                 <version>$spring-cloud.version</version>
45                 <type>pom</type>
46                 <scope>import</scope>
47             </dependency>
48         </dependencies>
49     </dependencyManagement>
50 
51     <build>
52         <plugins>
53             <plugin>
54                 <groupId>org.springframework.boot</groupId>
55                 <artifactId>spring-boot-maven-plugin</artifactId>
56             </plugin>
57         </plugins>
58     </build>
59 
60 </project>

添加application.xml

 1 server:
 2   port: 80
 3 spring:
 4   application:
 5     name: order-service
 6 eureka:
 7   client:
 8     service-url:
 9       defaultZone:
10         http://localhost:8761/eureka/

在EurekaClientApplication.java中添加标签：@EnableEurekaClient

 

 写一个测试：

 1 package com.angei.eurekaclient.Controller;
 2 
 3 import org.springframework.stereotype.Controller;
 4 import org.springframework.web.bind.annotation.GetMapping;
 5 import org.springframework.web.bind.annotation.PathVariable;
 6 import org.springframework.web.bind.annotation.ResponseBody;
 7 
 8 @Controller
 9 public class orderController 
10 
11     @GetMapping("/order/id")
12     @ResponseBody
13     public String findById(@PathVariable("id") Integer orderId)
14         if(orderId==2019)
15             return "\\"Id\\":1,\\"Title\\":\\"饿了么订单\\"";
16         else
17             return null;
18         
19     
20 

先启动服务器，再启动客户端：

 

 

Eureka名词概念与自我保护

Eureka名词概念

◆Register -服务注册，向Eureka进行注册登记

◆Renew -服务续约，30秒/次心跳包健康检查.90秒未收到剔除服务

◆Fetch Registries -获取服务注册列表,获取其他微服务地址

◆Cancel -服务下线，某个微服务通知注册中心暂停服务

◆Eviction -服务剔除,90秒未续约,从服务注册表进行剔除

Eureka自我保护机制

◆Eureka在运行期去统计心跳失败率在15分钟之内是否低于85%

◆如果低于85%，会将这些实例保护起来，让这些实例不会被剔除

◆关闭自我保护:eureka.server.enable-self-preservation: false

◆PS:如非网络特别不稳定,建议关闭

 

测试：

 

 

 

 关闭客服端，90秒后：

 

 

Eureka高可用配置(双节点_多节点)