Sentinel系列之（九）服务熔断

服务熔断

Sentinel整合Ribbon和OpenFeign

@SentinelResource的fallback

1. Ribbon系列
1.1 服务提供者

新建cloudalibaba-provider-payment9003和cloudalibaba-provider-payment9004

9003和9004是一样的，以9003为例

  • 建Module【cloudalibaba-provider-payment9003】

  • 改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-provider-payment9003</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>

  • 写YML

    server:
  port: 9003

spring:
  application:
    name: nacos-payment-provider
  cloud:
    nacos:
      discovery:
        server-addr: 192.168.59.128:8848 #配置Nacos地址

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

  • 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);
    }
}

  • 业务类

    package com.atguigu.springcloud.alibaba.controller;

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;

  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

  • 建Module【cloudalibaba-consumer-nacos-order84】

  • 改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>

  • 写YML

    server:
  port: 84
spring:
  application:
    name: nacos-order-consumer
  cloud:
    nacos:
      discovery:
        server-addr: 192.168.59.128:8848
    sentinel:
      transport:
        dashboard: 192.168.59.128:8080
        port: 8719
service-url:
  nacos-user-service: http://nacos-payment-provider

  • 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;

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

  • 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

    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.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;
  }
}
1.3 测试

  • Sentinel整合Ribbon

    • 启动单机版Nacos

    • 启动Sentinel

    • 启动cloudalibaba-provider-payment9003

    • 启动cloudalibaba-provider-payment9004

    • 启动cloudalibaba-consumer-nacos-order84

    • 多次访问http://localhost:84/consumer/fallback/1，发现轮询负载。

      至此，Nacos + Sentinel + Ribbon整合完成。

  • 不配置fallback和blockHandler

    • 当访问http://localhost:84/consumer/fallback/4或http://localhost:84/consumer/fallback/5时，由于接口手动抛出了异常，返回的是默认的错误页面。

  • 仅配置fallback

    • 修改CircleBreakerController，增加fallback相关配置，这里的fallback就相当于Hystrix中的服务降级。

          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.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",fallback = "handlerFallback") //fallback只负责处理接口抛出的异常
    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;
    }

    //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);
    }
}

      ​```

    • 再次访问http://localhost:84/consumer/fallback/5，执行了我们自定义的程序异常处理逻辑。

  • 仅配置blockHandler

    • 修改CircleBreakerController，增加blockHandler相关配置，去掉fallback相关配置

      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.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",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;
    }

    //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);
    }
}

    • 配置Sentinel，这里以降级规则为例

    • 访问一次http://localhost:84/consumer/fallback/5，由于没有自定义的程序异常处理，抛出了错误页面

    • 多次访问http://localhost:84/consumer/fallback/5，触发降级，执行了我们自定义的降级处理逻辑。

  • 配置fallback和blockHandler

    • 修改CircleBreakerController，同时配置fallback和blockHandler

      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.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", 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;
    }

    //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);
    }
}

    • 配置Sentinel，这里以流控规则为例

    • 访问一次http://localhost:84/consumer/fallback/4，由于程序本身会抛出异常，执行了自定义程序异常处理逻辑（fallback）。

    • 快速多次访问http://localhost:84/consumer/fallback/4，会直接执行自定义的降级处理逻辑（blockHandler）。

      结论：当接口本身会抛出异常，同时达到了降级条件，最后只会走自定义的降级处理逻辑。

  • exceptionsToIgnore属性

    • 修改CircleBreakerController，增加exceptionsToIgnore属性的配置，当接口抛出了该属性配置的异常类型时，不会走自定义的fallback的处理逻辑。

      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.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", 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);
    }
}

    • 访问http://localhost:84/consumer/fallback/4，没有执行自定义的fallback

    • 访问http://localhost:84/consumer/fallback/5，执行了自定义的fallback

    ​

2. Feign系列

Feign组件一般是用在消费侧的，修改cloudalibaba-consumer-nacos-order84

  • 改POM，增加OpenFeign的依赖

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

  • 改YML

    server:
  port: 84
spring:
  application:
    name: nacos-order-consumer
  cloud:
    nacos:
      discovery:
        server-addr: 192.168.59.128:8848
    sentinel:
      transport:
        dashboard: 192.168.59.128:8080
        port: 8719
service-url:
  nacos-user-service: http://nacos-payment-provider
# 激活Sentinel对Feign的支持
feign:
  sentinel:
    enabled: true

  • 主启动，增加@EnableFeignClients

      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);
      }
  }

  • 业务类

    • 创建PaymentService，带@FeignClient注解的业务接口

      package com.atguigu.springcloud.alibaba.service;

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);
}

    • 创建PaymentFallbackService

      package com.atguigu.springcloud.alibaba.service;

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"));
    }
}

    • 修改CircleBreakerController，增加如下代码

      // OpenFeign
@Resource
private PaymentService paymentService;

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

  • 测试

    启动cloudalibaba-provider-payment9003

    启动cloudalibaba-consumer-nacos-order84

    访问http://localhost:84/consumer/paymentSQL/1，成功

    关闭cloudalibaba-provider-payment9003，继续访问http://localhost:84/consumer/paymentSQL/1

    可以看到触发了OpenFeign的服务降级。

3. 熔断框架比较

posted @   刘二水  阅读(19)  评论(0)  编辑  收藏  举报
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