springCloud 学习笔记2 ribbon 实现客户端负载均衡

痛定思痛。 2022-03-30 04:47 116阅读 0赞

### maven基础 ###

*  ribbon基本介绍
 *   *  项目案例 客户端实现负载均衡结构图
     *  准备工作
     *   *  搭建eureak 服务端
         *  搭建eureak客户端，服务提供者
         *  搭建eureak客户端，服务消费者，集成ribbon模块
     *  测试自定义负载均衡器，注解实现
     *  测试自定义负载均衡器，配置实现实现

# ribbon基本介绍 #

Ribbon是Netflix发布的负载均衡器，一个基于HTTP和TCP的客户端负载均衡工具，Spring Cloud集成了Ribbon，结合Eureka，可实现客户端的负载均衡

## 项目案例 客户端实现负载均衡结构图 ##

![客户端负责均衡结构图：][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hpZ2hlcl9nYW8_size_16_color_FFFFFF_t_70]

## 准备工作 ##

1.  **搭建eureak服务端，作为服务注册中心使用**
2.  **搭建eureak客户端，作为服务提供者**
3.  **搭建eureak客户端，作为服务消费者，集成ribbon模块**

### 搭建eureak 服务端 ###

1, **pom文件配置**

<dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-web</artifactId>
          </dependency>
          <dependency>
              <groupId>org.springframework.cloud</groupId>
              <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
          </dependency>

**属性文件配置**

#服务端口
    server.port=8761
    #服务名称serviceCenter
    eureka.instance.hostname=yihongyuan
    #禁止本身注册
    eureka.client.register-with-eureka=false
    #禁止本身注册
    eureka.client.fetch-registry=false
    #服务中心地址
    eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/

2, **启动类**

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

### 搭建eureak客户端，服务提供者 ###

1, **pom文件配置**

<dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
         <dependency>
             <groupId>org.springframework.cloud</groupId>
             <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
         </dependency>

**属性文件配置**

spring:
     application:
       name: polices
    eureka:
    client:
     eureka-server-url:
       defautZone: http://localhost:8761/eureka/

2, **启动类**

@SpringBootApplication
    @EnableEurekaClient
    @ComponentScan(value = "com")
    public class EureakRibbonProductApplication { 
    
     public static void main(String[] args) { 
         Scanner scan = new Scanner(System.in);
         String port = scan.nextLine();
         new SpringApplicationBuilder(EureakRibbonProductApplication.class).properties("server.port=" + port).run(args);
     }
    
    }

3, **业务类**

@RestController
    public class PoliceController { 
    
     @RequestMapping(value = "/call/{id}", method = RequestMethod.GET, 
     		produces = MediaType.APPLICATION_JSON_VALUE)
     public Police call(@PathVariable Integer id, HttpServletRequest request) { 
     	Police p = new Police();
     	p.setId(id);
     	p.setName("angus");
     	p.setMessage(request.getRequestURL().toString());
     	return p;
     }
    }

4, **注册中心查看**  
![启动了两个客户端实例][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hpZ2hlcl9nYW8_size_16_color_FFFFFF_t_70 1]  
5, **业务类测试**  
![访问端口8081的客户端示例][8081]  
![访问端口号为8080的客户端示例][8080]

### 搭建eureak客户端，服务消费者，集成ribbon模块 ###

1, **pom文件配置**

<dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
         <dependency>
             <groupId>org.springframework.cloud</groupId>
             <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
         </dependency>

**属性文件配置**

server:
    port: 9000
    spring:
    application:
     name: erueka_ribbon_customer
    eureka:
    client:
     eureka-server-url:
       defautZone: http://localhost:8761/eureka/

2, **启动类**

@SpringBootApplication
    @EnableDiscoveryClient
    @ComponentScan(value = "com")
    @Configuration
    public class EurekaRibbonCustomerApplication { 
    
     public static void main(String[] args) { 
         SpringApplication.run(EurekaRibbonCustomerApplication.class, args);
     }
    
     @Bean
     @LoadBalanced
     public RestTemplate getRestTemplate() { 
         return new RestTemplate();
     }
    }

3, **业务类**

@Controller
    public class MyController { 
    
     @Autowired
     RestTemplate tpl;
    
     @GetMapping("/router")
     @ResponseBody
     public String router() { 
         System.out.println("rout...");
      // RestTemplate tpl = getRestTemplate();
         String json = tpl.getForObject("http://polices/call/1", String.class);
         return json;
     }

4, **注册中心查看**  
如图见  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hpZ2hlcl9nYW8_size_16_color_FFFFFF_t_70 1]  
5, **业务类测试**  
![客户端负载均衡访问8080服务提供者][8080 1]  
![客户端负载均衡访问8080服务提供者][8080 2]  
客户端默认使用轮询的方式访问8080，,8081实例

## 测试自定义负载均衡器，注解实现 ##

1，**自定义配置类**

规则类 rule
    public class MyRule implements IRule { 
    
     private ILoadBalancer lb;
    
     public Server choose(Object key) { 
         System.out.println("这是自定义的规则类");
         Random r = new Random();
         int randomNum = r.nextInt(10);
         List<Server> servers = lb.getAllServers();
         if (randomNum > 7) { 
             Server s = getServerByPort(servers, 8081);
             return s;
         }
         return getServerByPort(servers, 8080);
     }
    
     private Server getServerByPort(List<Server> servers, int port) { 
         for (Server s : servers) { 
             if (s.getPort() == port) { 
                 return s;
             }
         }
         return null;
     }
    
     public void setLoadBalancer(ILoadBalancer lb) { 
         this.lb = lb;
     }
    
     public ILoadBalancer getLoadBalancer() { 
         return lb;
     }
    }

配置类
    public class MyConfig { 
    
      @Bean
      public IRule getRule() { 
      	return new MyRule();
      }
    }

ribbon客户端类
    @RibbonClient(name = "polices", configuration = MyConfig.class)
    public class MyClient { 
    
    }

2，**测试**  
在访问http://127.0.0.1:9000/router 时候，服务提供着实例 8080被优先访问到  
![8080 1][]  
![在控制台上可以看到使用了自定义规则类][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hpZ2hlcl9nYW8_size_16_color_FFFFFF_t_70 2]

## 测试自定义负载均衡器，配置实现实现 ##

1，**在配置文件中使用配置类**

## ribbon自定义规则类
    polices:
    ribbon:
     NFLoadBalancerRuleClassName: com.bw.rule.MyRule

2，**测试**  
![自定义规则类被使用到][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hpZ2hlcl9nYW8_size_16_color_FFFFFF_t_70 3]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hpZ2hlcl9nYW8_size_16_color_FFFFFF_t_70]: /images/20220330/7a58f724babc48bb9adeb2a2f38aa807.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hpZ2hlcl9nYW8_size_16_color_FFFFFF_t_70 1]: /images/20220330/677a9eab544645d187d18a18505ed78f.png
[8081]: /images/20220330/0c711c5c325948e0a0b6758899b0d7cb.png
[8080]: /images/20220330/f31f1e48eba44bab83a67c992d4b7620.png
[8080 1]: /images/20220330/e760c49ed4554996b3472ea0aca5acb7.png
[8080 2]: /images/20220330/8ad5608f23b54bb28bd230b595c0bd12.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hpZ2hlcl9nYW8_size_16_color_FFFFFF_t_70 2]: /images/20220330/bc625a44583e42beaeff978ea74ea131.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hpZ2hlcl9nYW8_size_16_color_FFFFFF_t_70 3]: /images/20220330/a85601fec26c47df9d2d2a755884eb38.png