sentinel整合ribbon+openFeign+fallback

1. Ribbon系列

1.1 服务提供者

（1）module

新建cloudalibaba-provider-payment9003/9004，两个一样的做法

（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>cloud2021</artifactId>
        <groupId>com.atguigu.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>cloudalibaba-provider-payment9004</artifactId>
    <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>
</project>

（3）yaml

server:
  port: 9004

spring:
  application:
    name: nacos-payment-provider
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848 #配置Nacos地址

management:
  endpoints:
    web:
      exposure:
        include: '*'

（4）主启动类

package com.atguigu.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain9004 {

    public static void main(String[] args) {
        SpringApplication.run(PaymentMain9004.class,args);
        System.out.println("**********************************************");
        System.out.println("*****PaymentMain9004  start  successful*******");
        System.out.println("**********************************************");
    }
}

（5）业务类

import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.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;

    //模拟数据库
    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;
    }

}

1.2 服务消费者

（1）module

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>cloud2021</artifactId>
        <groupId>com.atguigu.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloudalibaba-consumer-nacos-order84</artifactId>

    <dependencies>
        <!--SpringCloud openfeign -->
        <!--
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        -->
        <!--SpringCloud ailibaba nacos -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!--SpringCloud ailibaba sentinel -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <!-- 引入自己定义的api通用包，可以使用Payment支付Entity -->
        <dependency>
            <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>
</project>

（3）yaml

server:
  port: 84

spring:
  application:
    name: nacos-order-consumer
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    sentinel:
      transport:
        #配置Sentinel dashboard地址
        dashboard: localhost:8080
        #默认8719端口，假如被占用会自动从8719开始依次+1扫描,直至找到未被占用的端口
        port: 8719

#消费者将要去访问的微服务名称(注册成功进nacos的微服务提供者)
service-url:
  nacos-user-service: http://nacos-payment-provider

# 激活Sentinel对Feign的支持
#feign:
#  sentinel:
#    enabled: false

（4）主启动类

package com.atguigu.springcloud;


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);
        System.out.println("******************************************************");
        System.out.println("*****OrderNacosMain84  start  successful**************");
        System.out.println("******************************************************");
    }
}

（5）业务类

package com.atguigu.springcloud.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();
    }
}

package com.atguigu.springcloud.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import lombok.extern.slf4j.Slf4j;
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
    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;
    }

}

（6）测试

http://localhost:84/consumer/fallback/1

1.3 测试

（1）Sentinel服务熔断无配置

没有任何配置 - 给用户error页面，不友好

@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
    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;
    }

}

http://localhost:84/consumer/fallback/1

http://localhost:84/consumer/fallback/4

http://localhost:84/consumer/fallback/5

（2）Sentinel服务熔断只配置fallback

fallback只负责业务异常

@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
    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;
    }

    //本例是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);
    }

}

http://localhost:84/consumer/fallback/1

http://localhost:84/consumer/fallback/4

http://localhost:84/consumer/fallback/5

（3）Sentinel服务熔断只配置blockHandler

blockHandler只负责sentinel控制台配置违规

@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
    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;
    }
    //本例是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);
    }*/

    //本例是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);
    }
}

http://localhost:84/consumer/fallback/1

http://localhost:84/consumer/fallback/4

http://localhost:84/consumer/fallback/5

（4）Sentinel服务熔断fallback和blockHandler都配置

若blockHandler和fallback 都进行了配置，则被限流降级而抛出BlockException时只会进入blockHandler处理逻辑

@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")
    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;
    }
    //本例是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);
    }
    //本例是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);
    }
}

http://localhost:84/consumer/fallback/1

http://localhost:84/consumer/fallback/4

http://localhost:84/consumer/fallback/5

（5）Sentinel服务熔断exceptionsToIgnore

exceptionsToIgnore，忽略指定异常，即这些异常不用兜底方法处理。

@RestController
@Slf4j
public class CircleBreakerController    

    ...

    @RequestMapping("/consumer/fallback/{id}")
    @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) {
            //exceptionsToIgnore属性有IllegalArgumentException.class，
            //所以IllegalArgumentException不会跳入指定的兜底程序。
            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;
    }

    ...
}

其他情况与（4）一样

2. Feign系列

修改84模块

84消费者调用提供者9003
Feign组件一般是消费侧

2.1 pom

<!--SpringCloud openfeign -->

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

2.2 yml

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

2.3 主启动类

import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

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

2.4 业务类

带@Feignclient注解的业务接口，fallback = PaymentFallbackService.class

import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.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);
}

import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.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"));
    }
}

@RestController
@Slf4j
public class CircleBreakerController {

    ...

    //==================OpenFeign
    @Resource
    private PaymentService paymentService;

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

2.5 测试

测试 - http://localhost:84/consumer/paymentSQL/1

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

服务熔断

1. Ribbon系列

1.1 服务提供者

（1）module

（2）pom

（3）yaml

（4）主启动类

（5）业务类

1.2 服务消费者

（1）module

（2）pom

（3）yaml

（4）主启动类

（5）业务类

（6）测试

1.3 测试

（1）Sentinel服务熔断无配置

（2）Sentinel服务熔断只配置fallback

（3）Sentinel服务熔断只配置blockHandler

（4）Sentinel服务熔断fallback和blockHandler都配置

（5）Sentinel服务熔断exceptionsToIgnore

2. Feign系列

2.1 pom

2.2 yml

2.3 主启动类

2.4 业务类

2.5 测试

3. 熔断框架比较