springcloud学习-12 Hystrix断路器【周阳springcloud2020学习笔记】

不念不忘少年蓝@ 2023-02-22 03:55 3阅读 0赞

作用：

*  服务降级：  
    程序运行异常、超时、服务熔断触发服务降级、线程池或信号量打满也会导致服务降级
 *  服务熔断：  
    类比保险丝达到最大服务访问后，直接拒绝访问，拉闸限电，然后调用服务降级的方法并返回友好提示  
    服务的降级->进而熔断->恢复调用链路
 *  服务限流：秒杀高并发等操作，严禁一窝蜂的过来拥挤，大家排队，一秒钟N个，有序进行  
    接近实时的监控

--------------------

**提供者hystrix-provider-payment8005**

1.新建hystrix-provider-payment8005  
2.pom

<dependencies>
    
        
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>
    
        
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    
        
        <dependency>
            <groupId>cn.chen.demo</groupId>
            <artifactId>api-common</artifactId>
            <version>${project.version}</version>
        </dependency>
    
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
    
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
    
        
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
        </dependency>
    
        
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
    
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
    
        
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
    
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

3.yml

server:
      port: 8005 # 端口号
    
    spring:
      # 应用名称
      application:
        name: hystrix-payment-service # 服务名称
    
      # 数据源
      datasource:
        type: com.alibaba.druid.pool.DruidDataSource # 数据库操作类型
        driver-class-name: org.gjt.mm.mysql.Driver # 数据库驱动
        #url: jdbc:mysql://192.168.221.129:3306/demo2020?useUnicode=true&characterEncoding=utf-8&useSSL=false
        url: jdbc:mysql://localhost:3306/demo2020?useUnicode=true&characterEncoding=utf-8&useSSL=false
        username: root
        password: 123456
    
      # 是否支持热部署
      devtools:
        restart:
          enabled: true
    
    eureka:
      client:
        register-with-eureka: true
        fetchRegistry: true
        service-url:
          defaultZone: http://localhost:7001/eureka # 单机版
          #defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka # 集群版
      instance:
        instance-id: payment8005
        prefer-ip-address: true
        # eureka客户端想服务端发动心跳的时间间隔，单位为秒（默认是30秒）。开发的时候可以设置小一些，以保证服务关闭后注册中心及时剔除服务
        lease-renewal-interval-in-seconds: 1
        # eureka服务端在收到最后一次心跳后等待时间上限，单位为秒（默认是90秒）。开发时候设置小一些
        lease-expiration-duration-in-seconds: 2
    
    mybatis:
      mapperLocations: classpath:mapper/*.xml #mapper文件
      type-aliases-package: cn.chen.cloud.entity  #所有entity别名所在包

4.主启动

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

5.业务类  
1)service

@Service
     public class PaymentService { 
    
     	/** * @Description 模拟访问成功情况 **/
     	public String IsOk(){ 
     		return "线程池："+Thread.currentThread().getName()+"，IsOk。";
     	}
    
     	/** * @Description 模拟访问失败情况 **/
     	public String IsTimeOut(int timeNumber){ 
     		try { 
     			TimeUnit.SECONDS.sleep(timeNumber);
     		}catch (Exception e) { 
     			e.printStackTrace();
     		}
     		return "线程池："+Thread.currentThread().getName()+"，IsTimeOut，耗时(秒)"+timeNumber;
     	}
     }

2)controller

@RestController
      @Slf4j
      @RequestMapping("/payment")
      public class PaymentController { 
    
      	@Resource
      	private PaymentService paymentService;
    
      	@GetMapping("/hystrix/ok")
      	public String ok(){ 
      		String result = paymentService.IsOk();
      		log.info("*******result:"+result);
      		return result;
      	}
      	@GetMapping("/hystrix/timeout")
      	public String timeOut(){ 
      		String result = paymentService.IsTimeOut(3);
      		log.info("*******result:"+result);
      		return result;
      	}
      }

6.启动7001（单机版）  
启动8005（Hystrix）

--------------------

**消费者hystrix-consumer-order80**

1.新建hystrix-consumer-order80  
2.pom依赖（参考consumer-order80）

<dependencies>
    
             
             <dependency>
                 <groupId>org.springframework.cloud</groupId>
                 <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
             </dependency>
    
             
             <dependency>
                 <groupId>org.springframework.cloud</groupId>
                 <artifactId>spring-cloud-starter-openfeign</artifactId>
             </dependency>
    
             
             <dependency>
                 <groupId>org.springframework.cloud</groupId>
                 <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
             </dependency>
    
             
             <dependency>
                 <groupId>cn.chen.demo</groupId>
                 <artifactId>api-common</artifactId>
                 <version>${project.version}</version>
             </dependency>
    
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-starter-web</artifactId>
             </dependency>
    
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-starter-actuator</artifactId>
             </dependency>
    
             
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-devtools</artifactId>
                 <scope>runtime</scope>
                 <optional>true</optional>
             </dependency>
    
             
             <dependency>
                 <groupId>org.projectlombok</groupId>
                 <artifactId>lombok</artifactId>
                 <optional>true</optional>
             </dependency>
    
             
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-starter-test</artifactId>
                 <scope>test</scope>
             </dependency>
         </dependencies>

3.yml配置（参考consumer-order80）

server:
          port: 80
    
        spring:
          application:
            name: hystrix-order-consumer
    
        eureka:
          client:
            register-with-eureka: true
            fetchRegistry: true
            service-url:
              defaultZone: http://localhost:7001/eureka # 单机版
              #defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka #集群版
          instance:
            instance-id: order80
            prefer-ip-address: true
    
        payment:
          #url: http://localhost:8001
          server:
            name: http://payment-service

4.主启动类

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

[**springcloud学习系列目录**][springcloud]

[springcloud]: https://blog.csdn.net/u010734213/article/details/107080320