Spring Cloud Alibaba Sentinel 服务熔断

谁践踏了优雅 2022-12-28 12:57 180阅读 0赞

### 文章目录 ###

*   *   *  1 摘要
         *  2 核心 Maven 依赖
         *  3 核心代码
         *   *  3.1 application 配置文件
             *  3.2 Service 层 - 核心Feign服务调用与熔断
             *  3.3 熔断回调方法
             *  3.4 熔断回调工厂
             *  3.5 Controller 控制层
             *  3.6 SpringBoot 启动类
             *  3.7 其他相关类
             *  3.8 手动标记 Sentinel 资源
         *  4 熔断测试
         *   *  4.1 准备工作
             *  4.2 正常接口请求
             *  4.3 接口限流，熔断测试
         *  5 推荐参考资料
         *  6 Github 源码

### 1 摘要 ###

微服务之间相互调用，如果有一个服务出现故障，无法对外提供服务，那么调用该服务的应用也会跟着陷入无线的等待，直至客户端出现链接超时，这种客户体验及其不好，而且严重影响系统的效率。熔断机制的出现，就是为了解决这个问题。微服务的熔断机制基本原理为当一个服务(A)调用另一个服务(B)的时候，如果后一个服务(B)出现故障，则不影响前一个服务(A)，同时前者能够及时提供反馈到客户端，避免用户长久等待。

Spring Cloud 中的Hystrix 就是一个著名的微服务熔断组件，Sentinel 对其进行了适配，写法上与 Hystrix 保持基本一致，从而让开发者的迁移更加方便。

本文将介绍基于 Spring Cloud Alibaba 2.2 使用 Sentinel 实现服务熔断。

准备工作:

[安装 Alibaba Sentinel][Alibaba Sentinel]

[了解 Spring Cloud Alibaba Sentinel 流量限制控制台][Spring Cloud Alibaba Sentinel]

Sentinel Gtihub: [https://github.com/alibaba/Sentinel][https_github.com_alibaba_Sentinel]

Spring Cloud Alibaba Github: [https://github.com/alibaba/spring-cloud-alibaba][https_github.com_alibaba_spring-cloud-alibaba]

### 2 核心 Maven 依赖 ###

./cloud-alibaba-consumer-sentinel/pom.xml

<dependencies>
            
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
                <version>${spring-cloud-openfeign.version}</version>
            </dependency>
    
            
            
    
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>com.alibaba.cloud</groupId>
                    <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                    <version>${spring-cloud-alibaba.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>

其中 `${spring-cloud-alibaba.version}` 的版本为 `2.2.3.RELEASE` , `${spring-cloud-openfeign.version}` 的版本为 `2.2.5.RELEASE`

**注意事项**: Spring Cloud Alibaba 2.2.3.RELEASE 版本支持的 Spring Boot 版本为 `2.3.1.RELEASE` ，建议在搭建项目时要保持版本的一致性，Spring Boot 版本过高或过低都可能导致不兼容问题

### 3 核心代码 ###

#### 3.1 application 配置文件 ####

./cloud-alibaba-consumer-sentinel/src/main/resources/application.yml

## config
    
    ## server
    server:
      port: 8608
    
    ## spring
    spring:
      application:
        name: cloud-alibaba-consumer-sentinel
      cloud:
        nacos:
          discovery:
            server-addr: 172.16.140.10:8688
        sentinel:
          transport:
            dashboard: 172.16.140.10:8666
            port: 8720
    
    
    ## feign
    feign:
      sentinel:
        enabled: true
    
    ## endpoint
    management:
      endpoints:
        web:
          exposure:
            include: "*"

配置简要说明:

`spring.application.name`: 应用名称， Nacos 服务名称

`spring.cloud.nacos.discovery.server-addr`: Nacos 服务注册中心地址

`spring.cloud.sentinel.transport.dashboard`: Sentinel 控制台地址，包括 ip 和端口

`spring.cloud.sentinel.transport.port`: 客户端与 Sentinel 控制台的通讯端口，是项目所在服务器的端口，不是 Sentinel 控制台所在服务器的端口

`feign.sentinel.enabled`: 这里需要手动开启 Sentinel 对 Feign 的支持

#### 3.2 Service 层 - 核心Feign服务调用与熔断 ####

./cloud-alibaba-consumer-sentinel/src/main/java/com/ljq/demo/springboot/alibaba/consumer/sentinel/service/NacosConsumerService.java

package com.ljq.demo.springboot.alibaba.consumer.sentinel.service;
    
    import com.ljq.demo.springboot.alibaba.consumer.sentinel.common.constant.NacosConst;
    import com.ljq.demo.springboot.alibaba.consumer.sentinel.model.param.HelloParam;
    import com.ljq.demo.springboot.alibaba.consumer.sentinel.service.fallback.ConsumerFallBackFactory;
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.cloud.openfeign.SpringQueryMap;
    import org.springframework.http.MediaType;
    import org.springframework.http.ResponseEntity;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestBody;
    
    
    /** * @Description: Nacos 服务消费者业务层 * @Author: junqiang.lu * @Date: 2020/12/2 */
    @FeignClient(name = NacosConst.CLOUD_ALIBABA_SENTINEL_DASHBOARD, fallbackFactory = ConsumerFallBackFactory.class)
    public interface NacosConsumerService { 
    
        /** * hello * @param helloParam * @return */
        @GetMapping(value = "/api/cloud/alibaba/sentinel/dashboard/hello", produces = { MediaType.APPLICATION_JSON_VALUE})
        ResponseEntity<String> hello(@SpringQueryMap HelloParam helloParam);
    
        /** * * @param helloParam * @return */
        @PostMapping(value = "/api/cloud/alibaba/sentinel/dashboard/replay", produces = { MediaType.APPLICATION_JSON_VALUE})
        ResponseEntity<String> replay(@RequestBody HelloParam helloParam);
    
    
    }

#### 3.3 熔断回调方法 ####

./cloud-alibaba-consumer-sentinel/src/main/java/com/ljq/demo/springboot/alibaba/consumer/sentinel/service/fallback/ConsumerFallBack.java

package com.ljq.demo.springboot.alibaba.consumer.sentinel.service.fallback;
    
    import com.ljq.demo.springboot.alibaba.consumer.sentinel.model.param.HelloParam;
    import com.ljq.demo.springboot.alibaba.consumer.sentinel.service.NacosConsumerService;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.http.ResponseEntity;
    
    /** * @Description: 熔断回调方法 * @Author: junqiang.lu * @Date: 2020/12/2 */
    @Slf4j
    public class ConsumerFallBack implements NacosConsumerService { 
    
        private Throwable throwable;
    
        public ConsumerFallBack(Throwable throwable) { 
            this.throwable = throwable;
        }
    
        /** * hello * @param helloParam * @return */
        @Override
        public ResponseEntity<String> hello(HelloParam helloParam) { 
            String result = "Sorry," + helloParam.getName() + ",网络拥堵,稍后重试";
            log.info("call back result: {}", result);
            log.error("{}", throwable.getMessage());
            return ResponseEntity.ok(result);
        }
    
        /** * 回复 * * @param helloParam * @return */
        @Override
        public ResponseEntity<String> replay(HelloParam helloParam) { 
            String result = "Sorry," + helloParam.getName() + ",网络拥堵,稍后重试";
            log.info("call back result: {}", result);
            log.error("{}", throwable.getMessage());
            return ResponseEntity.ok(result);
        }
    
    
    }

#### 3.4 熔断回调工厂 ####

./cloud-alibaba-consumer-sentinel/src/main/java/com/ljq/demo/springboot/alibaba/consumer/sentinel/service/fallback/ConsumerFallBackFactory.java

package com.ljq.demo.springboot.alibaba.consumer.sentinel.service.fallback;
    
    import feign.hystrix.FallbackFactory;
    import org.springframework.stereotype.Component;
    
    /** * @Description: Nacos 熔断工厂 * @Author: junqiang.lu * @Date: 2020/12/3 */
    @Component
    public class ConsumerFallBackFactory implements FallbackFactory<ConsumerFallBack> { 
    
        @Override
        public ConsumerFallBack create(Throwable cause) { 
            return new ConsumerFallBack(cause);
        }
    }

#### 3.5 Controller 控制层 ####

./cloud-alibaba-consumer-sentinel/src/main/java/com/ljq/demo/springboot/alibaba/consumer/sentinel/controller/NacosConsumerController.java

package com.ljq.demo.springboot.alibaba.consumer.sentinel.controller;
    
    import com.ljq.demo.springboot.alibaba.consumer.sentinel.model.param.HelloParam;
    import com.ljq.demo.springboot.alibaba.consumer.sentinel.service.NacosConsumerService;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.http.MediaType;
    import org.springframework.http.ResponseEntity;
    import org.springframework.web.bind.annotation.*;
    
    /** * @Description: nacos 服务消费者控制层 * @Author: junqiang.lu * @Date: 2020/12/2 */
    @Slf4j
    @RestController
    @RequestMapping("/api/nacos/consumer")
    public class NacosConsumerController { 
    
        @Autowired
        private NacosConsumerService consumerService;
    
        @GetMapping(value = "/hello", produces = { MediaType.APPLICATION_JSON_VALUE})
        public ResponseEntity<String> hello(HelloParam helloParam) { 
            ResponseEntity<String> response = consumerService.hello(helloParam);
            log.info("response: {}", response.getBody());
            return response;
        }
    
        @PostMapping(value = "/replay", produces = { MediaType.APPLICATION_JSON_VALUE})
        public ResponseEntity<String> replay(@RequestBody HelloParam helloParam) { 
            ResponseEntity<String> response = consumerService.replay(helloParam);
            log.info("response: {}", response.getBody());
            return response;
        }
    
    
    }

#### 3.6 SpringBoot 启动类 ####

./cloud-alibaba-consumer-sentinel/src/main/java/com/ljq/demo/springboot/alibaba/consumer/sentinel/CloudAlibabaConsumerSentinelApplication.java

package com.ljq.demo.springboot.alibaba.consumer.sentinel;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    /** * @author junqiang.lu */
    @EnableDiscoveryClient
    @EnableFeignClients
    @SpringBootApplication
    public class CloudAlibabaConsumerSentinelApplication { 
    
        public static void main(String[] args) { 
            SpringApplication.run(CloudAlibabaConsumerSentinelApplication.class, args);
        }
    
    }

`@EnableDiscoveryClient`: spring cloud 服务发现注解，使用该注解可以在服务注册中心发现、管理该服务

`@EnableFeignClients` ：启用 Feign 的注解

#### 3.7 其他相关类 ####

请求参数类

./cloud-alibaba-consumer-sentinel/src/main/java/com/ljq/demo/springboot/alibaba/consumer/sentinel/model/param/HelloParam.java

package com.ljq.demo.springboot.alibaba.consumer.sentinel.model.param;
    
    import lombok.Data;
    
    import java.io.Serializable;
    
    /** * @Description: 用户实体类 * @Author: junqiang.lu * @Date: 2020/12/2 */
    @Data
    public class HelloParam implements Serializable { 
    
        private static final long serialVersionUID = -686738885661126900L;
    
        /** * 用户名 */
        private String name;
    }

常量类

./cloud-alibaba-consumer-sentinel/src/main/java/com/ljq/demo/springboot/alibaba/consumer/sentinel/common/constant/NacosConst.java

package com.ljq.demo.springboot.alibaba.consumer.sentinel.common.constant;
    
    /** * @Description: Nacos 相关常量 * @Author: junqiang.lu * @Date: 2020/12/2 */
    public class NacosConst { 
    
        private NacosConst() { 
        }
    
        public static final String CLOUD_ALIBABA_SENTINEL_DASHBOARD = "cloud-alibaba-sentinel-dashboard";
    }

#### 3.8 手动标记 Sentinel 资源 ####

Sentinel 提供的注解 `@SentinelResource` 用于标记资源，其 `value` 属性即为资源识别编号，被标记后可以在 Sentinel 控制台对其进行流量监控和限制等操作，该注解不仅可以用在服务调用者上，还可以用在服务提供者上。本文主要介绍了 Sentinel 和 Feign 结合使用的示例，因此并没有用到该注解。在本示例中 `@SentinelResource` 可以再添加到 `cloud-alibaba-sentinel-dashboard` 项目 Controller 里提供的两个接口上。这样就可以做到更好地服务熔断。

更多信息可参考: [官方文档: Spring Cloud Alibaba Sentinel][Spring Cloud Alibaba Sentinel 1]

### 4 熔断测试 ###

#### 4.1 准备工作 ####

依次启动 Sentinel 控制台项目、待调用服务 `cloud-alibaba-sentinel-dashboard` 、当前项目服务 `cloud-alibaba-consumer-sentinel`

请求当前项目的两个接口(可暂不传参数，主要为了让 Sentinel 控制台显示当前服务)

打开 Sentinel 控制台

![image-20201216195825289][]

#### 4.2 正常接口请求 ####

接口一:

接口地址与请求参数:

http://127.0.0.1:8608/api/nacos/consumer/hello?name=%E8%92%99%E5%A8%9C%E4%B8%BD%E8%8E%8E

请求方式: GET

返回结果:

Hello,蒙娜丽莎

服务消费者(`cloud-alibaba-consumer-sentinel`)日志:

2020-12-17 13:34:31.130  INFO 7339 --- [nio-8608-exec-1] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hello,蒙娜丽莎

服务提供者(`cloud-alibaba-sentinel-dashboard`)日志:

2020-12-17 13:34:31.014  INFO 7346 --- [nio-8606-exec-1] .d.s.a.s.d.c.SentinelDashboardController : serverPort: 8606
    2020-12-17 13:34:31.015  INFO 7346 --- [nio-8606-exec-1] .d.s.a.s.d.c.SentinelDashboardController : result: Hello,蒙娜丽莎

接口二:

接口地址:

http://127.0.0.1:8608/api/nacos/consumer/replay

请求参数:

{ 
        "name": "马保国"
    }

请求方式: POST

返回结果:

Hi,马保国,I'm fine,Thank you.

服务消费者(`cloud-alibaba-consumer-sentinel`)日志:

2020-12-17 13:34:35.425  INFO 7339 --- [nio-8608-exec-2] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hi,马保国,I'm fine,Thank you.

服务提供者(`cloud-alibaba-sentinel-dashboard`)日志:

2020-12-17 13:34:35.422  INFO 7346 --- [nio-8606-exec-2] .d.s.a.s.d.c.SentinelDashboardController : result: Hi,马保国,I'm fine,Thank you.

Sentinel 控制台界面

![Sentinel 控制台][Sentinel]

#### 4.3 接口限流，熔断测试 ####

对服务提供者的接口进行限流，QPS 上限为 5

操作步骤：

点击左侧「cloud-alibaba-sentinel-dashboard」,点击「簇点链路」，在`hello` 和 `replay` 接口右侧点击「流控」按钮，将 QPS 设置为 5

![添加流量控制][249083d6e15dcaf22430711aeba3da7a.png]

添加成功后，点击左侧「流控规则」，展示设置的限流信息

![流控规则列表][53834a53f0a08a9450a704589f451fbe.png]

使用测试工具对接口进行测试

这里以 Postman 的 Runner 功能为例

![image-20201217135727892][]

![image-20201217140825715][]

请求的接口为服务消费者(`cloud-alibaba-consumer-sentinel`) 的两个接口

总共请求 1000 次，每间隔 10 毫秒请求一次，理论 QPS 为 100/2 = 50（Runner 是单线程串行请求接口的）

启动 Runner

Sentinel 控制台

![image-20201217141156685][]

![image-20201217141247365][]

服务消费者部分后台日志:

2020-12-17 14:12:02.061  INFO 7339 --- [nio-8608-exec-8] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hello,蒙娜丽莎
    2020-12-17 14:12:02.103  INFO 7339 --- [nio-8608-exec-9] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hi,马保国,I'm fine,Thank you.
    2020-12-17 14:12:02.144  INFO 7339 --- [io-8608-exec-10] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hello,蒙娜丽莎
    2020-12-17 14:12:02.190  INFO 7339 --- [nio-8608-exec-1] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : call back result: Sorry,马保国,网络拥堵,稍后重试
    2020-12-17 14:12:02.190 ERROR 7339 --- [nio-8608-exec-1] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : [429] during [POST] to [http://cloud-alibaba-sentinel-dashboard/api/cloud/alibaba/sentinel/dashboard/replay] [NacosConsumerService#replay(HelloParam)]: [Blocked by Sentinel (flow limiting)]
    2020-12-17 14:12:02.190  INFO 7339 --- [nio-8608-exec-1] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Sorry,马保国,网络拥堵,稍后重试
    2020-12-17 14:12:02.227  INFO 7339 --- [nio-8608-exec-2] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : call back result: Sorry,蒙娜丽莎,网络拥堵,稍后重试
    2020-12-17 14:12:02.227 ERROR 7339 --- [nio-8608-exec-2] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : [429] during [GET] to [http://cloud-alibaba-sentinel-dashboard/api/cloud/alibaba/sentinel/dashboard/hello?serialVersionUID=-686738885661126900&name=%E8%92%99%E5%A8%9C%E4%B8%BD%E8%8E%8E] [NacosConsumerService#hello(HelloParam)]: [Blocked by Sentinel (flow limiting)]
    2020-12-17 14:12:02.227  INFO 7339 --- [nio-8608-exec-2] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Sorry,蒙娜丽莎,网络拥堵,稍后重试
    2020-12-17 14:12:02.276  INFO 7339 --- [nio-8608-exec-3] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : call back result: Sorry,马保国,网络拥堵,稍后重试
    2020-12-17 14:12:02.276 ERROR 7339 --- [nio-8608-exec-3] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : [429] during [POST] to [http://cloud-alibaba-sentinel-dashboard/api/cloud/alibaba/sentinel/dashboard/replay] [NacosConsumerService#replay(HelloParam)]: [Blocked by Sentinel (flow limiting)]
    2020-12-17 14:12:02.276  INFO 7339 --- [nio-8608-exec-3] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Sorry,马保国,网络拥堵,稍后重试
    2020-12-17 14:12:02.324  INFO 7339 --- [nio-8608-exec-4] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : call back result: Sorry,蒙娜丽莎,网络拥堵,稍后重试
    2020-12-17 14:12:02.324 ERROR 7339 --- [nio-8608-exec-4] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : [429] during [GET] to [http://cloud-alibaba-sentinel-dashboard/api/cloud/alibaba/sentinel/dashboard/hello?serialVersionUID=-686738885661126900&name=%E8%92%99%E5%A8%9C%E4%B8%BD%E8%8E%8E] [NacosConsumerService#hello(HelloParam)]: [Blocked by Sentinel (flow limiting)]
    2020-12-17 14:12:02.324  INFO 7339 --- [nio-8608-exec-4] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Sorry,蒙娜丽莎,网络拥堵,稍后重试
    2020-12-17 14:12:02.374  INFO 7339 --- [nio-8608-exec-5] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : call back result: Sorry,马保国,网络拥堵,稍后重试
    2020-12-17 14:12:02.374 ERROR 7339 --- [nio-8608-exec-5] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : [429] during [POST] to [http://cloud-alibaba-sentinel-dashboard/api/cloud/alibaba/sentinel/dashboard/replay] [NacosConsumerService#replay(HelloParam)]: [Blocked by Sentinel (flow limiting)]
    2020-12-17 14:12:02.374  INFO 7339 --- [nio-8608-exec-5] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Sorry,马保国,网络拥堵,稍后重试
    2020-12-17 14:12:02.411  INFO 7339 --- [nio-8608-exec-6] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : call back result: Sorry,蒙娜丽莎,网络拥堵,稍后重试
    2020-12-17 14:12:02.411 ERROR 7339 --- [nio-8608-exec-6] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : [429] during [GET] to [http://cloud-alibaba-sentinel-dashboard/api/cloud/alibaba/sentinel/dashboard/hello?serialVersionUID=-686738885661126900&name=%E8%92%99%E5%A8%9C%E4%B8%BD%E8%8E%8E] [NacosConsumerService#hello(HelloParam)]: [Blocked by Sentinel (flow limiting)]
    2020-12-17 14:12:02.411  INFO 7339 --- [nio-8608-exec-6] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Sorry,蒙娜丽莎,网络拥堵,稍后重试
    2020-12-17 14:12:02.454  INFO 7339 --- [nio-8608-exec-7] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : call back result: Sorry,马保国,网络拥堵,稍后重试
    2020-12-17 14:12:02.454 ERROR 7339 --- [nio-8608-exec-7] c.l.d.s.a.c.s.s.f.ConsumerFallBack       : [429] during [POST] to [http://cloud-alibaba-sentinel-dashboard/api/cloud/alibaba/sentinel/dashboard/replay] [NacosConsumerService#replay(HelloParam)]: [Blocked by Sentinel (flow limiting)]
    2020-12-17 14:12:02.454  INFO 7339 --- [nio-8608-exec-7] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Sorry,马保国,网络拥堵,稍后重试
    2020-12-17 14:12:02.505  INFO 7339 --- [nio-8608-exec-8] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hello,蒙娜丽莎
    2020-12-17 14:12:02.557  INFO 7339 --- [nio-8608-exec-9] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hi,马保国,I'm fine,Thank you.
    2020-12-17 14:12:02.619  INFO 7339 --- [io-8608-exec-10] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hello,蒙娜丽莎
    2020-12-17 14:12:02.678  INFO 7339 --- [nio-8608-exec-1] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hi,马保国,I'm fine,Thank you.
    2020-12-17 14:12:02.759  INFO 7339 --- [nio-8608-exec-2] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hello,蒙娜丽莎
    2020-12-17 14:12:02.846  INFO 7339 --- [nio-8608-exec-3] c.l.d.s.a.c.s.c.NacosConsumerController  : response: Hi,马保国,I'm fine,Thank you.

Postman 部分日志:

![image-20201217141554548][]

测试结果可以看出服务提供者端的QPS 在限流之后最高只能达到5，超过的部分请求均被拒绝。在后台日志中可以看出请求被拒绝之后走了熔断方法。从Postman日志中可以看出一个完整请求的时间很短(50毫秒以内)，并没有处于长时间的等待，从而提升了用户体验。

至此，已经实现了使用 Sentinel 对服务进行限流，以及集成 Feign 对服务进行熔断控制的功能。

### 5 推荐参考资料 ###

[官方文档: Spring Cloud Alibaba Sentinel][Spring Cloud Alibaba Sentinel 1]

[Spring Cloud Alibaba系列教程 - Spring Cloud Alibaba 熔断(Sentinel)][Spring Cloud Alibaba_ - Spring Cloud Alibaba _Sentinel]

### 6 Github 源码 ###

**Gtihub 源码地址** : [https://github.com/Flying9001/springBootDemo][https_github.com_Flying9001_springBootDemo]

个人公众号:**404Code**,分享半个互联网人的技术与思考，感兴趣的可以关注.  
![404Code][]

[Alibaba Sentinel]: https://blog.csdn.net/mrqiang9001/article/details/111297739
[Spring Cloud Alibaba Sentinel]: https://blog.csdn.net/mrqiang9001/article/details/111297979
[https_github.com_alibaba_Sentinel]: https://github.com/alibaba/Sentinel
[https_github.com_alibaba_spring-cloud-alibaba]: https://github.com/alibaba/spring-cloud-alibaba
[Spring Cloud Alibaba Sentinel 1]: https://github.com/alibaba/spring-cloud-alibaba/wiki/Sentinel
[image-20201216195825289]: /images/20221120/1376ffb8b56c4b09a420b9f3cd17c74e.png
[Sentinel]: /images/20221120/ef4862ba73564437a81f50e39369fc39.png
[249083d6e15dcaf22430711aeba3da7a.png]: /images/20221120/9431c839b5d645d1a6912fade9a35294.png
[53834a53f0a08a9450a704589f451fbe.png]: /images/20221120/5ca8d161ba444c1c817899426b53fcb1.png
[image-20201217135727892]: /images/20221120/d1ab055cf0d84405b950d1fb2f63bf57.png
[image-20201217140825715]: /images/20221120/2f67ec20acb7489ba0a070e61d4994a1.png
[image-20201217141156685]: /images/20221120/c1219abdb39c4491aa013f2be97c03cc.png
[image-20201217141247365]: /images/20221120/952af798a01e4db0b431e4a6e83f8a24.png
[image-20201217141554548]: /images/20221120/91858f6c4959400793e8c1653ab86f26.png
[Spring Cloud Alibaba_ - Spring Cloud Alibaba _Sentinel]: https://www.jianshu.com/p/cdd939c8a52e
[https_github.com_Flying9001_springBootDemo]: https://github.com/Flying9001/springBootDemo
[404Code]: /images/20221120/b7550ec53bff46b9976cb417d3c6d965.png