Hystrix实现服务熔断_单机版

客官°小女子只卖身不卖艺 2021-12-10 07:17 325阅读 0赞

## 一、背景描述 ##

为了探究Hystrix实现服务熔断功能， 我们选用了 consul 作为注册中心，启动了一个服务端（waiter）、一个消费端（consumer）。我们关掉waiter 节点，验证 consumer 节点是否能正常熔断。 consul 启动及运行状态监控，不在这里描述， 我们默认 consul 已经正常运行。  
本地安装运行consul 参考：[https://jingyan.baidu.com/article/ca41422f732f961eaf99ed5f.html][https_jingyan.baidu.com_article_ca41422f732f961eaf99ed5f.html]

## 二、服务端 ##

**2.1 pom主要依赖**

<properties>
    		<java.version>1.8</java.version>
    		<spring-cloud.version>Greenwich.SR1</spring-cloud.version>
    </properties>
    	
    <dependencyManagement>
    		<dependencies>
    			<dependency>
    				<groupId>org.springframework.cloud</groupId>
    				<artifactId>spring-cloud-dependencies</artifactId>
    				<version>${spring-cloud.version}</version>
    				<type>pom</type>
    				<scope>import</scope>
    			</dependency>
    		</dependencies>
    </dependencyManagement>
    
        	<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.cloud</groupId>
    			<artifactId>spring-cloud-starter-consul-discovery</artifactId>
    		</dependency>

**2.2 配置文件**

application.properties

#0表示服务器随机端口
    server.port=0
    #consul  地址
    spring.cloud.consul.host=localhost
    #consul  端口
    spring.cloud.consul.port=8500
    spring.cloud.consul.discovery.prefer-ip-address=true

bootstrap.properties

#服务名称
    spring.application.name=waiter-service

**2.3 代码配置**

@PostMapping("/successKey")
        @ResponseBody
        public  String  getSuccessKey(){
            return  "hello wrold!  you have Key !";
        }
    
        @PostMapping("/pay")
        @ResponseBody
        public  String  pay(){
            return  "OK！ you pay  success ！";
        }

## 三、消费方 ##

**3.1 pom主要依赖**

<properties>
    		<java.version>1.8</java.version>
    		<spring-cloud.version>Greenwich.SR1</spring-cloud.version>
    </properties>
    	
    <dependencyManagement>
    		<dependencies>
    			<dependency>
    				<groupId>org.springframework.cloud</groupId>
    				<artifactId>spring-cloud-dependencies</artifactId>
    				<version>${spring-cloud.version}</version>
    				<type>pom</type>
    				<scope>import</scope>
    			</dependency>
    		</dependencies>
    </dependencyManagement>
    
        	<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.cloud</groupId>
    			<artifactId>spring-cloud-starter-consul-discovery</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
    		</dependency>

**3.2 配置文件**

application.properties

#表示服务器端口
    server.port=8090
    #consul  地址
    spring.cloud.consul.host=localhost
    #consul  端口
    spring.cloud.consul.port=8500
    spring.cloud.consul.discovery.prefer-ip-address=true
    #暴露所有接口
    management.endpoint.health.show-details=always
    feign.client.config.default.connect-timeout=500
    feign.client.config.default.read-timeout=500
    #启用hystrix熔断功能
    feign.hystrix.enabled=true

bootstrap.properties

#服务名称
    spring.application.name=customer-service

**3.3 代码配置**  
1）启动类上注释@EnableCircuitBreaker 表示启动断路器

@SpringBootApplication
    @Slf4j
    @EnableDiscoveryClient
    @EnableFeignClients
    @EnableCircuitBreaker
    public class CustomerServiceApplication {
    
    	public static void main(String[] args) {
    		SpringApplication.run(CustomerServiceApplication.class, args);
    	}
    
    	@Bean
    	public CloseableHttpClient httpClient() {
    		return HttpClients.custom()
    				.setConnectionTimeToLive(30, TimeUnit.SECONDS)
    				.evictIdleConnections(30, TimeUnit.SECONDS)
    				.setMaxConnTotal(200)
    				.setMaxConnPerRoute(20)
    				.disableAutomaticRetries()
    				.setKeepAliveStrategy(new CustomConnectionKeepAliveStrategy())
    				.build();
    	}
    }

2）CircuitBreakerService 用于演示基于接口类的fallback

@FeignClient(name = "waiter-service", contextId = "circuitBreaker",
            qualifier = "circuitBreakerService",fallback = FallbackCircuitBreakerService.class)
    // 如果用了Fallback，不要在接口上加@RequestMapping，path可以用在这里
    public interface CircuitBreakerService {
        @PostMapping("/waiter/successKey")
        String  getSuccessKey();
    
    }

3） CircuitBreakerService 接口异常时候，fallback类FallbackCircuitBreakerService

@Component
    public class FallbackCircuitBreakerService implements  CircuitBreakerService{
        @Override
        public String  getSuccessKey(){
            return  "Fall BackMock Return";
        }
    
    }

4）PayService 用于演示基于方法的fallback

@FeignClient(name = "waiter-service", contextId = "pay")
    // 如果用了Fallback，不要在接口上加@RequestMapping，path可以用在这里
    public interface PayService {
        @PostMapping("/waiter/pay")
        String  pay();
    }

5）CustomerController http 入口

@RestController
    @RequestMapping("/customer")
    @Slf4j
    public class CustomerController {
          @Autowired
        private CircuitBreakerService circuitBreakerService ;
        @Autowired
        private PayService  payService;
    
        @PostMapping("/pay" )
        //关联fallback方法
        @HystrixCommand(fallbackMethod = "methodFall")
        public Object pay(){
            return payService.pay();
        }
    
        @GetMapping("/key")
        public Object getKey(){
            return circuitBreakerService.getSuccessKey();
        }
    
        /**
         * 用于方法fallback
         * @return
         */
        public Object methodFall(){
            return "waiter barker method fallback";
        }
    }

## 四、熔断结果演示 ##

1.  基于接口类未熔断情况  
    [http://localhost:8090/customer/key][http_localhost_8090_customer_key]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70]
2.  基于方法未熔断情况  
    [http://localhost:8090/customer/pay][http_localhost_8090_customer_pay]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 1]
3.  基于接口类熔断情况  
    [http://localhost:8090/customer/key][http_localhost_8090_customer_key]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 2]
4.  基于方法熔断情况  
    [http://localhost:8090/customer/pay][http_localhost_8090_customer_pay]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 3]

[https_jingyan.baidu.com_article_ca41422f732f961eaf99ed5f.html]: https://jingyan.baidu.com/article/ca41422f732f961eaf99ed5f.html
[http_localhost_8090_customer_key]: http://localhost:8090/customer/key
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70]: /images/20211210/32af42a7650144e690336646dfb61aba.png
[http_localhost_8090_customer_pay]: http://localhost:8090/customer/pay
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 1]: /images/20211210/0557c896052d4e0da8b1da6d1e05fdf1.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 2]: /images/20211210/9081daa8c86b4654a4c071569e50f687.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/2019071323154623.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5,size_16,color_FFFFFF,t_70