SpringCloud Ribbon实战（三）

接着上一篇关于ribbon介绍（服务提供者只有一个我们似乎没有感觉到负载均衡）我们接着讲ribbon真正的负载均衡

我们就多创建两个微服务提供者，怎么创建微服务工程之前我们就讲过了这里不在多说，如果不懂请参考https://blog.csdn.net/ywl470812087/article/details/102636250

下面就是创建好的

1，pom.xml文件jar包依赖

microservicecloud-provider-dept-8002微服务工程pom.xml

<?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"><parent><artifactId>microservicecloud</artifactId><groupId>com.atguigu.springcloud</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>microservicecloud-provider-dept-8002</artifactId><dependencies><!-- 引入自己定义的api通用包，可以使用Dept部门Entity --><dependency><groupId>com.atguigu.springcloud</groupId><artifactId>microservicecloud-api</artifactId><version>${project.version}</version></dependency><!-- actuator监控信息完善 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><!-- 将微服务provider侧注册进eureka --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-eureka</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-config</artifactId></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId></dependency><dependency><groupId>ch.qos.logback</groupId><artifactId>logback-core</artifactId></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jetty</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId></dependency><!-- 修改后立即生效，热部署 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><optional>true</optional><scope>true</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><configuration><!--fork :  如果没有该项配置，可能这个devtools不会起作用，即应用不会restart--><fork>true</fork></configuration></plugin></plugins></build></project>

microservicecloud-provider-dept-8003微服务工程pom.xml

<?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"><parent><artifactId>microservicecloud</artifactId><groupId>com.atguigu.springcloud</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>microservicecloud-provider-dept-8003</artifactId><dependencies><!-- 引入自己定义的api通用包，可以使用Dept部门Entity --><dependency><groupId>com.atguigu.springcloud</groupId><artifactId>microservicecloud-api</artifactId><version>${project.version}</version></dependency><!-- actuator监控信息完善 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><!-- 将微服务provider侧注册进eureka --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-eureka</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-config</artifactId></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId></dependency><dependency><groupId>ch.qos.logback</groupId><artifactId>logback-core</artifactId></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jetty</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId></dependency><!-- 修改后立即生效，热部署 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><optional>true</optional><scope>true</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><configuration><!--fork :  如果没有该项配置，可能这个devtools不会起作用，即应用不会restart--><fork>true</fork></configuration></plugin></plugins></build></project>

2，yml配置文件

注意：#数据库密码根据自己的mysql来配置

server:port: 8002mybatis:config-location: classpath:mybatis/mybatis.cfg.xml  #mybatis所在路径type-aliases-package: com.atguigu.springcloud.entities #entity别名类mapper-locations:- classpath:mybatis/mapper/**/*.xml #mapper映射文件spring:application:name: microservicecloud-dept datasource:type: com.alibaba.druid.pool.DruidDataSourcedriver-class-name: org.gjt.mm.mysql.Driverurl: jdbc:mysql://localhost:3306/cloudDB02username: rootpassword: xxxx                             #数据库密码根据自己的mysql来配置dbcp2:min-idle: 5initial-size: 5max-total: 5max-wait-millis: 200eureka:client: #客户端注册进eureka服务列表内service-url: defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/instance:instance-id: microservicecloud-dept8002   #自定义服务名称信息prefer-ip-address: true     #访问路径可以显示IP地址info:app.name: atguigu-microservicecloudcompany.name: www.atguigu.combuild.artifactId: $project.artifactId$build.version: $project.version$

server:port: 8003                                  #端口mybatis:config-location: classpath:mybatis/mybatis.cfg.xml  #mybatis所在路径type-aliases-package: com.atguigu.springcloud.entities #entity别名类mapper-locations:- classpath:mybatis/mapper/**/*.xml #mapper映射文件spring:application:name: microservicecloud-dept datasource:type: com.alibaba.druid.pool.DruidDataSourcedriver-class-name: org.gjt.mm.mysql.Driverurl: jdbc:mysql://localhost:3306/cloudDB03           username: rootpassword: xxxx                              #数据库密码根据自己的mysql来配置dbcp2:min-idle: 5initial-size: 5max-total: 5max-wait-millis: 200eureka:client: #客户端注册进eureka服务列表内service-url: defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/instance:instance-id: microservicecloud-dept8003   #自定义服务名称信息prefer-ip-address: true     #访问路径可以显示IP地址info:app.name: atguigu-microservicecloudcompany.name: www.atguigu.combuild.artifactId: $project.artifactId$build.version: $project.version$

最关键的一点注意：微服务实例不能变统一 microservicecloud-dept

spring:application:name: microservicecloud-dept

之前我们讲过每个微服务可以拥有自己独立的数据库，这里我们就创建其他两个数据库

clouddb02 创建脚本（初始化几条数据）

DROP DATABASE IF EXISTS clouddb02 ;
CREATE DATABASE clouddb02 CHARACTER SET UTF8;
USE clouddb02;
CREATE TABLE dept (deptno BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT ,dname VARCHAR(60),db_source VARCHAR(60)
);INSERT INTO dept(dname,db_source) VALUES('开发部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('人事部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('财务部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('市场部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('运维部',DATABASE());SELECT * FROM dept;

clouddb03 创建脚本（初始化几条数据）

DROP DATABASE IF EXISTS clouddb03 ;
CREATE DATABASE clouddb03 CHARACTER SET UTF8;
USE clouddb03;
CREATE TABLE dept (deptno BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT ,dname VARCHAR(60),db_source VARCHAR(60)
);INSERT INTO dept(dname,db_source) VALUES('开发部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('人事部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('财务部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('市场部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('运维部',DATABASE());SELECT * FROM dept;

3，拷贝microservicecloud-provider-dept-8001到其他两个微服务工程

这里我就不讲了，相信大家都会。拷贝完成之后我们需要把主启动类的名字分别改成：DeptProvider8002_App DeptProvider8003_App

package com.atguigu.springcloud;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;@SpringBootApplication
@EnableEurekaClient //本服务启动后会自动注册进eureka服务中
@EnableDiscoveryClient //服务发现
public class DeptProvider8001_App {public static void main(String[] args) {SpringApplication.run(DeptProvider8001_App.class, args);}
}

拷贝和修改完成我们的3个微服务提供者就配置完成

下面我们就来测试一下：

1，首先启动eureka集群,如果不懂eureka集群请参考学习这篇文章，这里就不多说了

2，启动3个微服务提供者，如果不懂微服务提供者实现请参考https://blog.csdn.net/ywl470812087/article/details/102535582

自测启动是否成功：

3，启动客户端消费者

注意：现在consumer可是带着@LoadBalanced算法的

访问：http://localhost/consumer/dept/list

再次访问：http://localhost/consumer/dept/list

看见没有访问返回的结果是不是可以看出已经起到了负载均衡的效果轮询访问。

从注册中心我们也可以看见一个微服务下挂着三个实例

以上ribbon的负载均衡已经讲解完毕是不是觉得很简单

总结：Ribbon就是软负载均衡的客户端组件，可以和其他所需请求的客户端结合使用，和eureka结合只是其中一个实例