Resilience4j_服务调用端异常熔断

淩亂°似流年 2021-11-05 11:38 274阅读 0赞

## 一、背景描述 ##

由于Hystrix官方已经停止更新，Spring 官网推荐使用Resilience4j作为服务的熔断保护中间件，可见Resilience4j的重要性。  
为了探究Resilience4j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>io.github.resilience4j</groupId>
    			<artifactId>resilience4j-spring-boot2</artifactId>
    			<version>0.14.1</version>
    		</dependency>

**3.2 配置文件**

application.properties

server.port=8090
    
    management.endpoints.web.exposure.include=*
    management.endpoint.health.show-details=always
    
    feign.client.config.default.connect-timeout=500
    feign.client.config.default.read-timeout=500
    
    spring.cloud.consul.host=localhost
    spring.cloud.consul.port=8500
    spring.cloud.consul.discovery.prefer-ip-address=true
    #CircuitBreaker名称为key的熔断配置
    resilience4j.circuitbreaker.backends.key.failure-rate-threshold=50
    resilience4j.circuitbreaker.backends.key.wait-duration-in-open-state=5000
    resilience4j.circuitbreaker.backends.key.ring-buffer-size-in-closed-state=5
    resilience4j.circuitbreaker.backends.key.ring-buffer-size-in-half-open-state=3
    resilience4j.circuitbreaker.backends.key.event-consumer-buffer-size=10
    #CircuitBreaker名称为pay的熔断配置
    resilience4j.circuitbreaker.backends.pay.failure-rate-threshold=50
    resilience4j.circuitbreaker.backends.pay.wait-duration-in-open-state=5000
    resilience4j.circuitbreaker.backends.pay.ring-buffer-size-in-closed-state=5
    resilience4j.circuitbreaker.backends.pay.ring-buffer-size-in-half-open-state=3
    resilience4j.circuitbreaker.backends.pay.event-consumer-buffer-size=10

bootstrap.properties

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

**3.3 代码配置**  
1）启动类

@SpringBootApplication
    @Slf4j
    @EnableDiscoveryClient
    @EnableFeignClients
    @EnableAspectJAutoProxy
    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）PayService 用Feign方式调用waiter-server中的接口

@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();
    
        @PostMapping("/waiter/successKey")
        String  getSuccessKey();
    
    }

3）CustomerController http 入口

@RestController
    @RequestMapping("/customer")
    @Slf4j
    public class CustomerController {
    
        private CircuitBreaker circuitBreaker;
        @Autowired
        private PayService payService;
    
        //熔断实现方式一（基于注册熔断器）
        // CustomerController 的构造方法中注入明文“pay”的熔断器
        public CustomerController(CircuitBreakerRegistry registry) {
            circuitBreaker = registry.circuitBreaker("pay");
        }
    
        //熔断实现方式一（基于注册熔断器）
        //当下游接口异常时候返回“CircuitBreaker effect!!”
        @PostMapping("/pay" )
        public Object pay(){
                    return Try.ofSupplier(
                    CircuitBreaker.decorateSupplier(circuitBreaker,
                            () -> payService.pay()))
                    .recover(CircuitBreakerOpenException.class, "CircuitBreaker effect!!")
                    .get();
        }
    
        //熔断实现方式一（基于注解）
        //声明熔断器名称为“key”的熔断器
        @GetMapping("/key")
        @io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker(name = "key")
        public Object getKey(){
            return payService.getSuccessKey();
         }
     ｝

## 四、熔断结果演示 ##

1.  基于注解未熔断情况  
    [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.  基于注册熔断器方式未熔断情况  
    [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.  基于注解熔断情况  
    [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.  基于注册熔断器方式熔断情况  
    [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/20211105/2ca7227b0a85453a91bb8973c4a72737.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/20211105/b2832b570b554419a9aea1892f318b23.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 2]: /images/20211105/df749d82bc5a444aab672e0f016e054b.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 3]: /images/20211105/711154f6ac3d4c29b943cbdf1ae8574f.png