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

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>
    <!--SpringCloud ailibaba nacos -->
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    <dependency><!-- 引入自己定义的api通用包，可以使用Payment支付Entity -->
        <groupId>com.atguigu.springcloud</groupId>
        <artifactId>cloud-api-commons</artifactId>
        <version>${project.version}</version>
    </dependency>
    <!-- SpringBoot整合Web组件 -->
    <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>
    <!--日常通用jar包配置-->
    <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);
    }
}

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

结果

图说

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

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

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