Sentinel熔断Feign和Ribbon

布满荆棘的人生 2022-10-28 04:55 137阅读 0赞

> 整个项目请看gitee：[https://gitee.com/xwb1056481167/spring-cloud][https_gitee.com_xwb1056481167_spring-cloud]
> 
> sentinel的安装和项目集成：[https://blog.csdn.net/www1056481167/article/details/113679945][https_blog.csdn.net_www1056481167_article_details_113679945]
> 
> 相关项目Ribbon:cloudalibaba-provider-payment9003，cloudalibaba-provider-payment9004
> 
> Feign:cloudalibaba-consumer-nacos-order84
> 
> nacos的配置安装请到：[https://blog.csdn.net/www1056481167/article/details/113612177][https_blog.csdn.net_www1056481167_article_details_113612177]查看

# **Ribbon熔断** #

## 服务提供者9003,9004 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d3dzEwNTY0ODExNjc_size_16_color_FFFFFF_t_70][]

1、新建cloudalibaba-provider-payment9003(9004下同)

<dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    
    <dependency>
        <groupId>org.xwb.springcloud</groupId>
        <artifactId>cloud-api-commons</artifactId>
        <version>1.0-SNAPSHOT</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>

2、yml配置

server:
      port: 9002
    spring:
      application:
        name: nacos-payment-provider
      cloud:
        nacos:
          discovery:
            server-addr: localhost:8848 #配置Nacos地址
    management:
      endpoints:
        web:
          exposure:
            include:  '*'

3、主启动类

@SpringBootApplication
    @EnableDiscoveryClient
    public class PaymentMain9003 {
        public static void main(String[] args) {
            SpringApplication.run(PaymentMain9002.class, args);
        }
    }

4、controller

@RestController
    public class PaymentController {
        @Value("\${server.port}")
        private String serverPort;
        public static HashMap<Long, Payment> hashMap = new HashMap<>();
        static {
            hashMap.put(1l, new Payment(1L, "210374208734KJEWFKW0U20sklfw0uor023u4"));
            hashMap.put(2l, new Payment(2L, "3498hofwsefhls93984rfhseohf2890343rwe"));
            hashMap.put(3l, new Payment(3L, "09snkjdfhjoiwhefdsnfjkhweo5235wefhwee"));
        }
        @GetMapping("/paymentSQL/{id}")
        public CommonResult paymentSQL(@PathVariable("id") Long id) {
            Payment payment = hashMap.get(id);
            CommonResult<Payment> result = new CommonResult<>(200, "from mysql,serverPort" + serverPort, payment);
            return result;
        }
    }

## 服务消费者cloudalibaba-consumer-nacos-order84 ##

1、pom.xml

<dependency>
        <groupId>com.alibaba.csp</groupId>
        <artifactId>sentinel-datasource-nacos</artifactId>
    </dependency>
    
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
    </dependency>

2、yml

server:
      port: 84
    spring:
      application:
        name: nacos-order-consumer
      cloud:
        nacos:
          discovery:
            server-addr: localhost:8848
        sentinel:
          transport:
            dashboard: localhost:8080
            # 默认8719端口，假如被占用会自动从8719开始一次+1稻苗，知道找到违背占用的端口
            port: 8719
    # 消费者将要去访问的服务名称(注册进nacos的服务提供者名称)
    service-url:
      nacos-user-service: http://nacos-payment-provider

3、主启动类

@SpringBootApplication
    @EnableDiscoveryClient
    public class OrderNacosMain84 {
        public static void main(String[] args) {
            SpringApplication.run(OrderNacosMain84.class, args);
        }
    }

4、负载均衡

@Configuration
    public class ApplicationContextConfig {
        @Bean
        @LoadBalanced
        public RestTemplate getLoadBalanced() {
            return new RestTemplate();
        }
    }

5、controller

@Slf4j
    @RestController
    public class CirleBreakerController {
        public static final String SERVICE_URL = "http://nacos-payment-provider";
        @Resource
        private RestTemplate restTemplate;
    
        @RequestMapping("/consumer/fallback/{id}")
        @SentinelResource(value = "fallback")
        public CommonResult<Payment> fallback(@PathVariable Long id) {
            CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/" + id, CommonResult.class);
            if (id == 4) {
                throw new IllegalArgumentException("IllegalArgumentException,非法参数异常");
            } else if (result.getData() == null) {
                throw new NullPointerException("NullPointerException,该id没有对应的记录，空指针异常");
            }
            return result;
        }
        public CommonResult<Payment> fallback(BlockException blockException) {
            return new CommonResult<Payment>(444, "", null);
        }
    }

### 测试 ###

启动顺序nacos，sentinel,9003,9004,最后启动调用方84  
1、@SentinelResource(value = "fallback", fallback = "handlerFallback") **fallback**

@RequestMapping("/consumer/fallback/{id}")
    @SentinelResource(value = "fallback", fallback = "handlerFallback")//只负责业务异常
    public CommonResult<Payment> fallback(@PathVariable Long id) {
        CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/" + id, CommonResult.class);
        if (id == 4) {
            throw new IllegalArgumentException("IllegalArgumentException,非法参数异常");
        } else if (result.getData() == null) {
            throw new NullPointerException("NullPointerException,该id没有对应的记录，空指针异常");
        }
        return result;
    }
    public CommonResult handlerFallback(@PathVariable("id") Long id, Throwable e) {
        Payment payment = new Payment(id, null);
        return new CommonResult(444, "兜底异常handlerFallback，exception内容" + e.getMessage(), payment);
    }

测试结果  
![20210205155142519.png][]  
2、测试@SentinelResource(value = "fallback", blockHandler = "handlerFallback")**blockHandler 。****blockHandler只负责sentinel控制台的配置**

@SentinelResource(value = "fallback", blockHandler = "blockHandler")//blockHandler只负责sentinel控制台的配置
    public CommonResult<Payment> fallback(@PathVariable Long id) {
        CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/" + id, CommonResult.class);
        if (id == 4) {
            throw new IllegalArgumentException("IllegalArgumentException,非法参数异常");
        } else if (result.getData() == null) {
            throw new NullPointerException("NullPointerException,该id没有对应的记录，空指针异常");
        }
        return result;
    }
    public CommonResult blockHandler(@PathVariable("id")Long id, BlockException blockException){
        Payment payment=new Payment(id,null);
        return new CommonResult(445,"blockHandler-sentinel限流，无此流水，blockException:"+blockException.getMessage(),payment);
    }

测试结果(第一次异常页面，连续一秒内刷新超过2次，出现sentinel的限流规则)

![20210205155316255.png][]

3、如果fallback和blockHandler都配置了，该怎么执行

@RequestMapping("/consumer/fallback/{id}")
    @SentinelResource(value = "fallback",fallback = "handlerFallback", blockHandler = "blockHandler")
    public CommonResult<Payment> fallback(@PathVariable Long id) {
        CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/" + id, CommonResult.class);
        if (id == 4) {
            throw new IllegalArgumentException("IllegalArgumentException,非法参数异常");
        } else if (result.getData() == null) {
            throw new NullPointerException("NullPointerException,该id没有对应的记录，空指针异常");
        }
        return result;
    }
    public CommonResult blockHandler(@PathVariable("id")Long id, BlockException blockException){
        Payment payment=new Payment(id,null);
        return new CommonResult(445,"blockHandler-sentinel限流，无此流水，blockException:"+blockException.getMessage(),payment);
    }
    public CommonResult handlerFallback(@PathVariable("id") Long id, Throwable e) {
        Payment payment = new Payment(id, null);
        return new CommonResult(444, "兜底异常handlerFallback，exception内容" + e.getMessage(), payment);
    }

结果(刷新浏览器1秒超过2次)

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d3dzEwNTY0ODExNjc_size_16_color_FFFFFF_t_70 1][]

> **若blockHandler和fallback都配置了，则被限流降级而抛出BlockException时只会进入blockHandler处理逻辑**

## exceptionsToIgnore ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d3dzEwNTY0ODExNjc_size_16_color_FFFFFF_t_70 2][]

# Fenign熔断 #

## 修改cloudalibaba-consumer-nacos-order84使用feign调用 ##

1、pom.xml

<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>

2、aplication.yml

# 激活sentinel对feign的支持
    feign:
      sentinel:
        enabled: true

3、开启对feign的支持@EnableFeignClients

@SpringBootApplication
    @EnableDiscoveryClient
    @EnableFeignClients
    public class OrderNacosMain84 {
        public static void main(String[] args) {
            SpringApplication.run(OrderNacosMain84.class, args);
        }
    }

4、openFeign提供接口调用OpenClient

@FeignClient(value = "nacos-payment-provider", fallback = PaymentFallbackService.class)
    public interface PaymentService {
        @GetMapping("/paymentSQL/{id}")
        public CommonResult paymentSQL(@PathVariable("id") Long id);
    }
    @Component
    public class PaymentFallbackService implements PaymentService {
        @Override
        public CommonResult paymentSQL(Long id) {
            return new CommonResult<Payment>(4444,"",new Payment(id,"errorSerial"));
        }
    }

## 测试 ##

> 启动nacos,sentinel,9003,9004,84，访问一下地址
> 
> 1、 [http://localhost:84/consumer/paymentSQL/1  访问结果(正常访问)][http_localhost_84_consumer_paymentSQL_1_]  
> 2、此时关闭9003，或者9004，再次刷新访问如下效果

![20210205160421840.png][]

会发现调用失败，服务自动降级

[https_gitee.com_xwb1056481167_spring-cloud]: https://gitee.com/xwb1056481167/spring-cloud
[https_blog.csdn.net_www1056481167_article_details_113679945]: https://blog.csdn.net/www1056481167/article/details/113679945
[https_blog.csdn.net_www1056481167_article_details_113612177]: https://blog.csdn.net/www1056481167/article/details/113612177
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d3dzEwNTY0ODExNjc_size_16_color_FFFFFF_t_70]: /images/20221024/518e38af711f414e80baf533ab2b3300.png
[20210205155142519.png]: /images/20221024/3ecd04c394644f7eb9772d07bab981cd.png
[20210205155316255.png]: /images/20221024/1726dc0c14344495b1077f7dd117c6e9.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d3dzEwNTY0ODExNjc_size_16_color_FFFFFF_t_70 1]: /images/20221024/8d932c8b3a3f4853abf335d95a0957d9.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d3dzEwNTY0ODExNjc_size_16_color_FFFFFF_t_70 2]: /images/20221024/8198471b3f4d430389d72ca746390331.png
[http_localhost_84_consumer_paymentSQL_1_]: http://localhost:84/consumer/paymentSQL/1%28%E6%AD%A3%E5%B8%B8%E8%AE%BF%E9%97%AE%29
[20210205160421840.png]: /images/20221024/09bbae6664e448069321bfcb602ca53f.png