SpringCloud Hoxton版 + SpringCloud alibaba学习笔记（13）-- SpringCloud Alibaba Sentinel 服务熔断功能

亦凉 2023-01-04 10:26 199阅读 0赞

### 一、sentinel整合ribbon+openFeign+fallback ###

### 二、Ribbon系列 ###

#### 1、启动nacos和sentinel ####

#### 2、提供者9003/9004 ####

##### ①、新建cloudalibaba-provider-payment9003/9004 #####

##### ②、POM #####

<dependencies>
        
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.atguigu.springcloud</groupId>
            <artifactId>cloud-api-commons</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 #####

server:
      port: 9003
    
    spring:
      application:
        name: nacos-payment-provider
      cloud:
        nacos:
          discovery:
            server-addr: localhost:8848 #配置Nacos地址
    
    management:
      endpoints:
        web:
          exposure:
            include: '*'

记得修改不同的端口号

##### ④、主启动 #####

package com.atguigu.springcloud.alibaba;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    
    
    @SpringBootApplication
    @EnableDiscoveryClient
    public class PaymentMain9003
    { 
        public static void main(String[] args) { 
            SpringApplication.run(PaymentMain9003.class, args);
        }
    }

##### ⑤、业务类 #####

package com.atguigu.springcloud.alibaba.controller;
    
    import com.atguigu.springcloud.alibaba.entities.CommonResult;
    import com.atguigu.springcloud.alibaba.entities.Payment;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.HashMap;
    
    @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,"28a8c1e3bc2742d8848569891fb42181"));
            hashMap.put(2L,new Payment(2L,"bba8c1e3bc2742d8848569891ac32182"));
            hashMap.put(3L,new Payment(3L,"6ua8c1e3bc2742d8848569891xt92183"));
        }
    
        @GetMapping(value = "/paymentSQL/{id}")
        public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id){ 
            Payment payment = hashMap.get(id);
            CommonResult<Payment> result = new CommonResult(200,"from mysql,serverPort: "+serverPort,payment);
            return result;
        }
    }

##### ⑥、测试地址 #####

http://localhost:9003/paymentSQL/1

#### 3、消费者84 ####

##### ①、新建cloudalibaba-consumer-nacos-order84 #####

##### ②、POM #####

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <parent>
            <artifactId>cloud2020</artifactId>
            <groupId>com.atguigu.springcloud</groupId>
            <version>1.0-SNAPSHOT</version>
        </parent>
        <modelVersion>4.0.0</modelVersion>
    
        <artifactId>cloudalibaba-consumer-nacos-order84</artifactId>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</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>
            <dependency>
                <groupId>com.atguigu.springcloud</groupId>
                <artifactId>cloud-api-commons</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>
    
    </project>

##### ③、YML #####

server:
      port: 84
    
    spring:
      application:
        name: nacos-order-consumer
      cloud:
        nacos:
          discovery:
            server-addr: localhost:8848
        sentinel:
          transport:
            dashboard: localhost:8080
            port: 8719
    
    service-url:
      nacos-user-service: http://nacos-payment-provider

##### ④、主启动 #####

package com.atguigu.springcloud.alibaba;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @EnableDiscoveryClient
    @SpringBootApplication
    @EnableFeignClients
    public class OrderNacosMain84
    { 
        public static void main(String[] args) { 
            SpringApplication.run(OrderNacosMain84.class, args);
        }
    }

##### ⑤、业务类 #####

ApplicationContextConfig

package com.atguigu.springcloud.alibaba.config;
    
    import org.springframework.cloud.client.loadbalancer.LoadBalanced;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.client.RestTemplate;
    
    
    @Configuration
    public class ApplicationContextConfig
    { 
        @Bean
        @LoadBalanced
        public RestTemplate getRestTemplate()
        { 
            return new RestTemplate();
        }
    }

CircleBreakerController的全部源码

package com.atguigu.springcloud.alibaba.controller;
    
    import com.alibaba.csp.sentinel.annotation.SentinelResource;
    import com.alibaba.csp.sentinel.slots.block.BlockException;
    import com.atguigu.springcloud.alibaba.entities.CommonResult;
    import com.atguigu.springcloud.alibaba.entities.Payment;
    
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;
    
    import javax.annotation.Resource;
    
    
    @RestController
    @Slf4j
    public class CircleBreakerController { 
       
        public static final String SERVICE_URL = "http://nacos-payment-provider";
    
        @Resource
        private RestTemplate restTemplate;
    
       
        
        @RequestMapping("/consumer/fallback/{id}")
        //@SentinelResource(value = "fallback") //没有配置
        //@SentinelResource(value = "fallback",fallback = "handlerFallback") //fallback只负责业务异常
        //@SentinelResource(value = "fallback",blockHandler = "blockHandler") //blockHandler只负责sentinel控制台配置违规
        @SentinelResource(value = "fallback",fallback = "handlerFallback",blockHandler = "blockHandler",
                exceptionsToIgnore = { IllegalArgumentException.class})
        public CommonResult<Payment> fallback(@PathVariable Long id) { 
            CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/"+id, CommonResult.class,id);
    
            if (id == 4) { 
                throw new IllegalArgumentException ("IllegalArgumentException,非法参数异常....");
            }else if (result.getData() == null) { 
                throw new NullPointerException ("NullPointerException,该ID没有对应记录,空指针异常");
            }
    
            return result;
        }
      
        //fallback
        public CommonResult handlerFallback(@PathVariable  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);
        }
      
        //blockHandler
        public CommonResult blockHandler(@PathVariable  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);
        }
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70]  
没有任何配置

@RestController
    @Slf4j
    public class CircleBreakerController
    { 
        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,id);
    
            if (id == 4) { 
                throw new IllegalArgumentException ("IllegalArgumentException,非法参数异常....");
            }else if (result.getData() == null) { 
                throw new NullPointerException ("NullPointerException,该ID没有对应记录,空指针异常");
            }
    
            return result;
        }

给客户error页面，不友好  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 1]  
结果  
![在这里插入图片描述][20210109154045704.png]  
图说  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 2]

### 三、Feign系列 ###

#### 1、修改84模块 ####

#### 2、POM ####

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

#### 3、YML ####

#### 4、业务类 ####

##### ①、带@FeignClient注解的业务接口 #####

package com.atguigu.springcloud.alibaba.service;
    
    import com.atguigu.springcloud.alibaba.entities.CommonResult;
    import com.atguigu.springcloud.alibaba.entities.Payment;
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    
    @FeignClient(value = "nacos-payment-provider",fallback = PaymentFallbackService.class)
    public interface PaymentService
    { 
        @GetMapping(value = "/paymentSQL/{id}")
        public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id);
    }

##### ②、fallback = PaymentFallbackService.class #####

##### ③、PaymentFallbackService实现类 #####

package com.atguigu.springcloud.alibaba.service;
    
    import com.atguigu.springcloud.alibaba.entities.CommonResult;
    import com.atguigu.springcloud.alibaba.entities.Payment;
    import org.springframework.stereotype.Component;
    
    @Component
    public class PaymentFallbackService implements PaymentService
    { 
        @Override
        public CommonResult<Payment> paymentSQL(Long id)
        { 
            return new CommonResult<>(44444,"服务降级返回,---PaymentFallbackService",new Payment(id,"errorSerial"));
        }
    }

##### ④、Controller #####

// OpenFeign
    @Resource
    private PaymentService paymentService;
    
    @GetMapping(value = "/consumer/paymentSQL/{id}")
    public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id) { 
        return paymentService.paymentSQL(id);
    }

#### 5、主启动 ####

添加@EnableFeignClients启动Feign的功能

package com.atguigu.springcloud.alibaba;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    
    @EnableDiscoveryClient
    @SpringBootApplication
    @EnableFeignClients
    public class OrderNacosMain84
    { 
        public static void main(String[] args) { 
            SpringApplication.run(OrderNacosMain84.class, args);
        }
    }

#### 6、http://lcoalhost:84/consumer/openfeign/1 ####

#### 7、http://lcoalhost:84/consumer/paymentSQL/1 ####

#### 8、测试84调用9003，此时故意关闭9003微服务提供者，看84消费侧自动降级，不会被耗死 ####

### 四、熔断框架比较 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 3]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 4]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70]: /images/20221119/cf54456edfb946d4a2e5a8d31dd30164.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 1]: /images/20221119/379aef85bd9042edaf8b5c0b2dec6097.png
[20210109154045704.png]: /images/20221119/4ea0629c764041f393c685570e2029b5.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20210109154106834.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20210109155741827.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 4]: https://img-blog.csdnimg.cn/20210109155752452.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM=,size_16,color_FFFFFF,t_70