深刻spring cloud(2)

時間 2019-11-19

標籤深刻 spring cloud 欄目 Spring 简体版

原文原文鏈接

服務發現之Consul實現

系列目錄：java

Spring Cloud的服務發現有2種實現方式，一個是Euraka服務，一個是基於Consul的服務。本文先講講Eureka的服務發現實現。web

什麼是Spring Cloud Eureka?

Spring Cloud Eureka 模塊提供的功能是被動式的服務發現。 spring cloud eureka 分爲兩部分：spring

@@EnableDiscoveryClient: 該註解代表應用既做爲eureka實例又爲eureka client 能夠發現註冊的服務
@EnableEurekaServer: 該註解代表應用爲eureka服務，有能夠聯合多個服務做爲集羣，對外提供服務註冊以及發現功能

** 什麼是服務發現?** 服務發現就像聊天室一個,每一個用戶來的時候去服務器上註冊,這樣他的好友們就能看到你,你同時也將獲取好友的上線列表. 在微服務中,服務就至關於聊天室的用戶,而服務註冊中心就像聊天室服務器同樣,目前服務發現的解決方案有Eureka , Consul ,Etcd , Zookeeper ,SmartStack ,等等。本文就來說講Eureka,如圖所示,Eureka Client經過HTTP(或者TCP,UDP)去Eureka Server註冊和獲取服務列表,爲了高可用通常會有多個Eureka Server組成集羣。Eureka會移除那些心跳檢查未到達的服務。apache

搭建服務註冊中心: 創建Eureka Server 端

<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>
    <groupId>com.zrx</groupId>
    <artifactId>minaret-eureka-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>minaret-eureka-server</name>
    <description>Eureka註冊中心</description>

    <!-- org.springframework.booot 父類 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.RELEASE</version>
    </parent>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Dalston.SR1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>


    <!--  屬性配置文件 -->
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
        <spring.boot.admin.server>1.5.0</spring.boot.admin.server>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- 服務發現 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>de.codecentric</groupId>
            <artifactId>spring-boot-admin-starter-client</artifactId>
            <version>${spring.boot.admin.server}</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

啓動應用Application.javasegmentfault

@SpringBootApplication
@EnableEurekaServer
public class EurekaApplication {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(EurekaApplication.class, args);
    }

}

配置application.yml服務器

server:
   port: 8761
spring:
   application:
      name: eureka-service
eureka:
  client:
    registerWithEureka: false # 禁止 註冊中心，註冊本身做爲服務，默認是能夠的
    fetchRegistry: false # 禁止 註冊中心，註冊本身做爲服務，默認是能夠的，本地是單點so，設置爲false
  server:
    waitTimeInMsWhenSyncEmpty: 0
    evictionIntervalTimerInMs: 4000
  instance:
      hostname: peer1 #對應的hostname
      metadataMap:
        instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}

註冊服務提供者

創建Eureka Client 端，例如user-microservice , 這是用戶服務。app

<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>
    <groupId>com.zrx</groupId>
    <artifactId>minaret-sys-provider-user</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>minaret-sys-provider-user</name>
    <description>minaret-sys-provider-user</description>

    <!-- org.springframework.booot 父類 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.RELEASE</version>
    </parent>

    <properties>
        <spring.boot.admin.server>1.5.0</spring.boot.admin.server>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- Euraka -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <!-- end  -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.16</version>
        </dependency>
        <dependency>
            <groupId>de.codecentric</groupId>
            <artifactId>spring-boot-admin-starter-client</artifactId>
            <version>${spring.boot.admin.server}</version>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Brixton.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Application.classdom

@EnableDiscoveryClient
@SpringBootApplication
public class SysUserApplication {

    public static void main(String[] args) {
        new SpringApplicationBuilder(SysUserApplication.class).web(true).run(args);
    }
}

server:
  port: 3333
spring:
  application.name: user-microservice-service

# z指定註冊中心的位置
eureka:
  client:
     serviceUrl:
        defaultZone: http://localhost:8761/eureka/