一、ribbon的作用和含义

Ribbon是Netflix发布的负载均衡器，它有助于控制HTTP和TCP客⼾端的⾏为。为Ribbon，配置服务提供者的地址列表后，Ribbon就可基于某种负载均衡算法，⾃动地帮助服务消费者去请求。Ribbon默认为我们提供了很多的负载均衡算法，例如轮询、随机等。当然，我们也可为Ribbon实现⾃定义的负载均衡算法。在SpringCloud中，当Ribbon与Eureka配 合使⽤时，Ribbon可⾃动从EurekaServer获取服务提供者的地址列表，并基于负载均衡算法，请求其中⼀个服务提供者的实例 （为了服务的可靠性，⼀个微服务可能部署多个实例）。

二、使用步骤

1.引入jar包

  1.                <!--   引入eureka客户端,eureka内部集成了ribbon     -->
  2.         <dependency>
  3.             <groupId>org.springframework.cloud</groupId>
  4.             <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
  5.         </dependency>

2.完整pom文件内容

  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>
  6.     <parent>
  7.         <artifactId>com.springcloud</artifactId>
  8.         <groupId>com.sc2020</groupId>
  9.         <version>1.0-SNAPSHOT</version>
  10.     </parent>
  12.     <groupId>com.example</groupId>
  13.     <artifactId>consumer-eureka-client81</artifactId>
  14.     <version>1.0.0-SNAPSHOT</version>
  15.     <name>consumer-client81</name>
  16.     <description>Demo project for Spring Boot</description>
  19.     <properties>
  20.         <java.version>1.8</java.version>
  21.     </properties>
  22.     <dependencies>
  24.         <dependency>
  25.             <groupId>com.sc2020</groupId>
  26.             <artifactId>cloud-payment8001</artifactId>
  27.             <version>1.0-SNAPSHOT</version>
  28.         </dependency>
  29.         <dependency>
  30.             <groupId>com.sc2020</groupId>
  31.             <artifactId>cloud-api-commons</artifactId>
  32.             <version>1.0-SNAPSHOT</version>
  33.         </dependency>
  35.         <dependency>
  36.             <groupId>org.springframework.boot</groupId>
  37.             <artifactId>spring-boot-starter-web</artifactId>
  38.         </dependency>
  39.         <dependency>
  40.             <groupId>org.springframework.boot</groupId>
  41.             <artifactId>spring-boot-starter-actuator</artifactId>
  42.         </dependency>
  43.         <dependency>
  44.             <groupId>org.mybatis.spring.boot</groupId>
  45.             <artifactId>mybatis-spring-boot-starter</artifactId>
  46.         </dependency>
  47.         <dependency>
  48.             <groupId>com.alibaba</groupId>
  49.             <artifactId>druid-spring-boot-starter</artifactId>
  50.             <version>1.1.10</version>
  51.         </dependency>
  52.         <dependency>
  53.             <groupId>mysql</groupId>
  54.             <artifactId>mysql-connector-java</artifactId>
  55.         </dependency>
  56.         <dependency>
  57.             <groupId>org.springframework.boot</groupId>
  58.             <artifactId>spring-boot-starter-jdbc</artifactId>
  59.         </dependency>
  60.         <dependency>
  61.             <groupId>org.springframework.boot</groupId>
  62.             <artifactId>spring-boot-starter-test</artifactId>
  63.             <scope>test</scope>
  64.         </dependency>
  65.         <dependency>
  66.             <groupId>org.springframework.boot</groupId>
  67.             <artifactId>spring-boot-devtools</artifactId>
  68.             <scope>runtime</scope>
  69.             <optional>true</optional>
  70.         </dependency>
  71.         <!--   引入eureka客户端     -->
  72.         <dependency>
  73.             <groupId>org.springframework.cloud</groupId>
  74.             <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
  75.         </dependency>
  77.     </dependencies>
  79. </project>

3. application配置文件

  1. server:
  2.   port: 81
  4. eureka:
  5.   client:
  6.     register-with-eureka: true   #是否将自己注册到注册中心,集群必须设置为true配合ribbon
  7.     fetch-registry: true    #是否从服务端抓取已有的注册信息
  8.     service-url:
  9.       defaultZone: http://eureka7001.com:7001/eureka  #服务注册中心路径,一般为localhost
  10.   instance:
  11.     instance-id: consumer-client81
  12.     prefer-ip-address: true
  13. spring:
  14.   datasource:
  15.     type: com.alibaba.druid.pool.DruidDataSource
  16.     driver-class-name: org.gjt.mm.mysql.Driver
  17.     url: jdbc:mysql://101.34.49.127:3306/cloud?useUnicode=true&amp;characterEncoding=utf-8&amp;useSSL=false
  18.     username: 数据库名称
  19.     password: 数据库密码
  20.   application:
  21.     name: consumer-client
  23. mybatis:
  24.   mapper-locations: classpath:mapper/*.xml

4.main启动类

  1. @SpringBootApplication
  2. @EnableEurekaClient
  3. //name表示使用负载均衡的服务名称,configuration是指定负载均衡策略类
  4. @RibbonClient(name = "cloud-eureka-service",configuration = MyselfRule.class)
  5. public class ConsumerEurekaClient81Application {
  7.     public static void main(String[] args) {
  8.         SpringApplication.run(ConsumerEurekaClient81Application.class, args);
  9.     }
  11. }

5.负载均衡配置类MyselfRule

  1. package com.example.consumerclient81.springcloud.config;
  3. import com.netflix.loadbalancer.*;
  4. import org.springframework.cloud.client.loadbalancer.LoadBalanced;
  5. import org.springframework.context.annotation.Bean;
  6. import org.springframework.context.annotation.Configuration;
  7. import org.springframework.web.client.RestTemplate;
  9. /**
  10.  * @description:
  11.  * @author: xiaYZ
  12.  * @createDate: 2021/11/16
  13.  * @version: 1.0
  14.  */
  15. @Configuration
  16. public class MyselfRule {
  18.     //设置RestTemplate
  19.     @Bean
  20.     //调用微服务项目,并负载均衡
  21.     @LoadBalanced
  22.     public RestTemplate getRestTemplate(){
  23.         return new RestTemplate();
  24.     }
  26.     /**
  27.      * description: 随机轮训策略
  28.      * version: 1.0
  29.      * date: 2021/11/30 13:17
  30.      * author: xiaYZ
  31.      * iteration: 迭代说明
  32.      * @param 
  33.      * @return 
  34.      */
  35.     @Bean
  36.     public IRule myRule(){
  37.         return new RandomRule();
  38.     }
  40.     /**
  41.      * description: 轮询策略,Ribbon默认策略
  42.      * version: 1.0
  43.      * date: 2021/11/30 13:23
  44.      * author: xiaYZ
  45.      * iteration: 迭代说明
  46.      * @param 
  47.      * @return 
  48.      */
  49.     //@Bean
  50.     public  IRule myRule2(){
  51.         return  new RoundRobinRule();
  52.     }
  54.     /**
  55.      * description: 重试策略
  56.      * version: 1.0
  57.      * date: 2021/11/30 13:25
  58.      * author: xiaYZ
  59.      * iteration: 迭代说明
  60.      * @param 
  61.      * @return 
  62.      */
  63.     //@Bean
  64.     public  IRule myRule3(){
  65.         return new RetryRule();
  66.     }
  68.     /**
  69.      * description: 最低并发策略
  70.      * version: 1.0
  71.      * date: 2021/11/30 13:26
  72.      * author: xiaYZ
  73.      * iteration: 迭代说明
  74.      * @param 
  75.      * @return 
  76.      */
  77.     //@Bean
  78.     public IRule myRule4(){
  79.         return new BestAvailableRule();
  80.     }
  82.     /**
  83.      * description: 可用过滤策略
  84.      * version: 1.0
  85.      * date: 2021/11/30 13:26
  86.      * author: xiaYZ
  87.      * iteration: 迭代说明
  88.      * @param 
  89.      * @return 
  90.      */
  91.     //@Bean
  92.     public IRule myRule5(){
  93.         return new AvailabilityFilteringRule();
  94.     }
  96.     /**
  97.      * description: 响应时间加权策略
  98.      * version: 1.0
  99.      * date: 2021/11/30 13:27
  100.      * author: xiaYZ
  101.      * iteration: 迭代说明
  102.      * @param 
  103.      * @return 
  104.      */
  105.     //@Bean
  106.     public IRule myRule6(){
  107.         return new WeightedResponseTimeRule();
  108.     }
  110.     /**
  111.      * description: 区域权衡策略
  112.      * version: 1.0
  113.      * date: 2021/11/30 13:27
  114.      * author: xiaYZ
  115.      * iteration: 迭代说明
  116.      * @param 
  117.      * @return 
  118.      */
  119.     //@Bean
  120.     public IRule myRule7(){
  121.         return new ZoneAvoidanceRule();
  122.     }
  126. }

6.Controller控制层代码

  1.    @Resource
  2.     RestTemplate restTemplate;
  4.     public static final String PAYMENT_URL = "http://cloud-eureka-client";
  6.     @GetMapping(value = "getMessage")
  7.     public String getMessage(){
  8.         //调用cloud-eureka-client服务中方法
  9.         String forObject = restTemplate.getForObject( PAYMENT_URL +"/paymentController/getPortMessage", String.class);
  10.         return forObject;
  11.     }

7.效果展示

4.ribbon负载均衡策略 - 图1

4.ribbon负载均衡策略 - 图2

4.ribbon负载均衡策略 - 图3

项目地址: https://gitee.com/xyz1041221997/springcloud.git