SpringCloud组件一之Eureka注册中心（G版本）

野性酷女 2022-03-26 10:43 242阅读 0赞

## 1.实战 ##

在IDEA在构建一个Maven项目，项目里面创建两个SpringBoot项目，registry(注册中心)，provider(服务提供者)。  
SpringBoot 的版本为 2.1.4。  
SpringCloud的版本为G版本。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMDA4NTM1_size_16_color_FFFFFF_t_70]

## 2.Eureka ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMDA4NTM1_size_16_color_FFFFFF_t_70 1]

### 2.1 注册中心Eureka ###

很简单，建一个项目，添加Eureka依赖，配置一下，收工。  
注意一个问题就可以，版本兼容问题，springboot版本与Eureka  
配置：

server:
      port: 10010
    spring:
      application:
        name: eureka-server
    eureka:
      client:
        service-url:
          defaultZone: http://127.0.0.1:${ server.port}/eureka/
        register-with-eureka: false
        fetch-registry: false

启动类上添加注释

@SpringBootApplication
    @EnableEurekaServer
    public class RegistryApplication { 
    
        public static void main(String[] args) { 
            SpringApplication.run(RegistryApplication.class, args);
        }
    
    }

pom

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.4.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.lll</groupId>
        <artifactId>registry</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>registry</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
            <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>${ spring-cloud.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

访问http://127.0.0.1:10010/，就可以访问注册中心了

### 2.2修改服务提供方 ###

只要将服务注册进去，开启客户端，收工

*  注册

server:
      port: 8081
    spring:
      application:
        name: server-procider
    eureka:
      client:
        service-url:
          defaultZone: http://127.0.0.1:10010/eureka
      instance:
        prefer-ip-address: true # 当其它服务获取地址时提供ip而不是hostname
        ip-address: 127.0.0.1 # 指定自己的ip信息，不指定的话会自己寻找

*  开启Eureka客户端

@SpringBootApplication
    @EnableEurekaClient
    public class ProviderApplication { 
        public static void main(String[] args) { 
            SpringApplication.run(ProviderApplication.class, args);
        }
    }

POM文件

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.4.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.lll</groupId>
        <artifactId>provider</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>provider</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
            <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-security</artifactId>
                <version>RELEASE</version>
                <scope>compile</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>${ spring-cloud.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    </project>

## 3.Eureka的其他配置 ##

*  服务提供方

eureka:
      instance:
      	##服务失效时间
        lease-expiration-duration-in-seconds: 90
        ##服务续约(renew)的间隔
        lease-renewal-interval-in-seconds: 30

*  服务调用方

eureka:
      client:
      ##每隔多久时间拉去一次服务列表
        registry-fetch-interval-seconds: 5

*  失效剔除和自我保护  
    自我保护：当一个服务未按时进行心跳续约时，Eureka会统计最近15分钟心跳失败的服务实例的比例是否超过了85%。

eureka:
      server:
        enable-self-preservation: false # 关闭自我保护模式（缺省为打开）
        ##每隔多久剔除失效的服务
        eviction-interval-timer-in-ms: 1000 # 扫描失效服务的间隔时间（缺省为60*1000ms）

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