Sentinel熔断功能之整合ribbon+openFeign+fallback

Sentinel整合ribbon+openFeign+fallback:

一、Sentinel整合Ribbon：

第一步：启动nacos和setinel后台服务：

省略…

第二步：创建提供者模块9003和9004：

（1）新建maven模块: cloudalibaba-provider-payment9003

（2）改pom:

        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-nacos-discovery
        
        
        
            com.alibaba.csp
            sentinel-datasource-nacos
        
        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-sentinel
        
        
        
            org.springframework.cloud
            spring-cloud-starter-openfeign
        
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
        
            org.springframework.boot
            spring-boot-starter-actuator
        
        
            org.springframework.boot
            spring-boot-devtools
            runtime
            true
        
        
            org.projectlombok
            lombok
            true
        
        
            cn.hutool
            hutool-core
            5.6.5
        

    

（3）写yml:

server:
  port: 9003

spring:
  application:
    name: nacos-payment-provider
  cloud:
    nacos:
      discovery: #注册中心的地址
        server-addr: 192.168.211.205:1111 #这里做了nginx的均衡负载

management: #springboot端点暴露，这里我们暴露所有端点
  endpoints:
    web:
      exposure:
        exclude: '*'

（4）主启动类：com.fan.springcloud.PaymentProviderMain9003

package com.fan.springcloud;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class PaymentProviderMain9003 {
    public static void main(String[] args) {
        SpringApplication.run(PaymentProviderMain9003.class,args);
    }
}

（5）业务类：controller.PaymentController:

package com.fan.springcloud.controller;

import com.fan.springcloud.entity.CommonResult;
import com.fan.springcloud.entity.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 hashMap = new HashMap();
    //模拟数据库，存了三条记录
    static{
        hashMap.put(1L,new Payment(1L,"1234567890QWERTYUIOP1"));
        hashMap.put(2L,new Payment(2L,"1234567890QWERTYUIOP2"));
        hashMap.put(3L,new Payment(3L,"1234567890QWERTYUIOP3"));
    }
    @GetMapping(value = "/paymentSQL/{id}")
    public CommonResult paymentSQL(@PathVariable("id") Long id ){
        Payment payment = hashMap.get(id);
        CommonResult paymentCommonResult =
                new CommonResult<>(200, "来自数据库，端口号：" +
                serverPort, payment);
        return paymentCommonResult;
    }
}

同理，新建一个提供者cloudalibaba-provider-payment9004：

测试：启动两个微服务9003和9004：

网页测试地址：localhost:9003/paymentSQL/1

第三步：创建消费者模块84：

（1）新建消费者模块：cloudalibaba-consumer-nacos-order84

（2）修改pom：

        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-nacos-discovery
        
        
        
            com.alibaba.csp
            sentinel-datasource-nacos
        
        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-sentinel
        
        
        
            org.springframework.cloud
            spring-cloud-starter-openfeign
        
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
        
            org.springframework.boot
            spring-boot-starter-actuator
        
        
            org.springframework.boot
            spring-boot-devtools
            runtime
            true
        
        
            org.projectlombok
            lombok
            true
        
        
            cn.hutool
            hutool-core
            5.6.5
        

    

（3）写yml:

server:
  port: 84

spring:
  application:
    name: nacos-order-consumer
  cloud:
    nacos:
      discovery:
        server-addr: 192.168.211.205:1111
    sentinel:
      transport:
        dashboard: localhost:8080  #配置sentinel 的仪表盘地址
        port: 8719   #默认仪表盘8719端口

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

（4）主启动类：com.fan.springcloud.OrderNacosMain84

package com.fan.springcloud;

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

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

（5）业务类：

负载均衡配置类：config.ApplicationContextConfig:

package com.fan.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();
    }
}

controller.CircleBreakerController类:分如下几种情况：

---

---

情况一：没有任何配置：给客户error页面，不友好

package com.fan.springcloud.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.fan.springcloud.entity.CommonResult;
import com.fan.springcloud.entity.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 {
    //依赖注入restTemplate
    @Resource
    private RestTemplate restTemplate;

    @RequestMapping("/consumer/fallback/{id}") //restful风格的路径参数
    @SentinelResource(value = "fallback") //没有配置
    public CommonResult fallback(@PathVariable("id") Long id){
        log.info("测试fallback------");
        CommonResult result =
         restTemplate.getForObject("http://nacos-payment-provider/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没有对应的记录，空指针异常！！！");
        }

        return result;
    }

}

测试地址：localhost:84/consumer/fallback/1

多刷新几下地址：发现负载均衡到9003和9004端口：

换一个id测试：

当数据库没有查到数据的时候出现错误页面，不友好：

情况二：带fallback：
fallback只负责java业务逻辑异常:

package com.fan.springcloud.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.fan.springcloud.entity.CommonResult;
import com.fan.springcloud.entity.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 {
    //依赖注入restTemplate
    @Resource
    private RestTemplate restTemplate;

    @RequestMapping("/consumer/fallback/{id}") //restful风格的路径参数
    //@SentinelResource(value = "fallback") //没有配置
    @SentinelResource(value = "fallback",fallback = "handlerFallback") //fallback只负责java业务逻辑异常
    public CommonResult fallback(@PathVariable("id") Long id){
        log.info("测试fallback------");
        CommonResult result =
         restTemplate.getForObject("http://nacos-payment-provider/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没有对应的记录，空指针异常！！！");
        }
        return result;
    }

    //兜底应急fallback方法handlerFallback
    public CommonResult handlerFallback(@PathVariable Long id,Throwable e){
        Payment payment = new Payment(id,"null");
        return new CommonResult(444,"兜底应急fallback方法handlerFallback," +
                "异常内容"+e.getMessage(),payment);
    }

}

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

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

情况三：带blockhandler:

blockHandler只负责sentinel控制台配置违规:

控制台配置：

测试：

情况四：两种都配置：

package com.fan.springcloud.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.fan.springcloud.entity.CommonResult;
import com.fan.springcloud.entity.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 {
    //依赖注入restTemplate
    @Resource
    private RestTemplate restTemplate;

    @RequestMapping("/consumer/fallback/{id}") //restful风格的路径参数
    //@SentinelResource(value = "fallback") //没有配置
    //@SentinelResource(value = "fallback",fallback = "handlerFallback") //fallback只负责java业务逻辑异常
    //@SentinelResource(value = "fallback",blockHandler = "blockHandler") //blockHandler只负责sentinel控制台配置违规
    @SentinelResource(value = "fallback",blockHandler = "blockHandler",fallback = "handlerFallback") //blockHandler只负责sentinel控制台配置违规
    public CommonResult fallback(@PathVariable("id") Long id){
        log.info("测试fallback------");
        CommonResult result =
         restTemplate.getForObject("http://nacos-payment-provider/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没有对应的记录，空指针异常！！！");
        }
        return result;
    }

    //兜底应急fallback方法handlerFallback
    public CommonResult handlerFallback(@PathVariable Long id,Throwable e){
        Payment payment = new Payment(id,"null");
        return new CommonResult(444,"兜底应急fallback方法handlerFallback," +
                "异常内容"+e.getMessage(),payment);
    }

    //blockHandler的限流异常处理
    public CommonResult blockHandler(@PathVariable("id") Long id, BlockException blockException){
        Payment payment = new Payment(id, "null");
        return new CommonResult(445,"blockHandler-sentinel限流处理，" +
                "无此流水，blockException："+blockException.getMessage());
    }
}

控制台添加流控：

忽略异常：

测试：

二、Sentinel整合OpenFeign:

pom:

        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-nacos-discovery
        
        
        
            com.alibaba.csp
            sentinel-datasource-nacos
        
        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-sentinel
        
        
        
            org.springframework.cloud
            spring-cloud-starter-openfeign
        
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
        
            org.springframework.boot
            spring-boot-starter-actuator
        
        
            org.springframework.boot
            spring-boot-devtools
            runtime
            true
        
        
            org.projectlombok
            lombok
            true
        
        
            cn.hutool
            hutool-core
            5.6.5
        
    

yml:

server:
  port: 84

spring:
  application:
    name: nacos-order-consumer
  cloud:
    nacos:  #nacos服务发现地址
      discovery:
        server-addr: 192.168.211.205:1111
    sentinel:  #sentinel监控端口和地址
      transport:
        dashboard: localhost:8080  #配置sentinel 的仪表盘地址
        port: 8719   #默认仪表盘8719端口

#消费者将要去访问的微服务的名称（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openfeign的 支持
feign:
  sentinel:
    enabled: true

主启动类：

package com.fan.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;

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

原先不使用openFeign时，我们是在controler中通过中间的restTemplate来进行远程调用，现在换成接口调用的形式，方便。

openfeign 接口：

package com.fan.springcloud.service;

import com.fan.springcloud.entity.CommonResult;
import com.fan.springcloud.entity.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 paymentSQL(@PathVariable("id") Long id);

}

接口的实现类：这里也是兜底的类:

package com.fan.springcloud.service;

import com.fan.springcloud.entity.CommonResult;
import com.fan.springcloud.entity.Payment;
import org.springframework.stereotype.Component;

@Component
public class PaymentFallbackService implements PaymentService{
    @Override
    public CommonResult paymentSQL(Long id) {
        return new CommonResult<>(4444,"服务降级返回，PaymentFallbackService" +
                "",new Payment(id,"错误"));
    }
}

controller:

package com.fan.springcloud.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.fan.springcloud.entity.CommonResult;
import com.fan.springcloud.entity.Payment;
import com.fan.springcloud.service.PaymentService;
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 {
    //依赖注入restTemplate
    @Resource
    private RestTemplate restTemplate;

    @RequestMapping("/consumer/fallback/{id}") //restful风格的路径参数
    //@SentinelResource(value = "fallback") //没有配置
    //@SentinelResource(value = "fallback",fallback = "handlerFallback") //fallback只负责java业务逻辑异常
    //@SentinelResource(value = "fallback",blockHandler = "blockHandler") //blockHandler只负责sentinel控制台配置违规
    @SentinelResource(value = "fallback",blockHandler = "blockHandler",fallback = "handlerFallback") //blockHandler只负责sentinel控制台配置违规
    public CommonResult fallback(@PathVariable("id") Long id){
        log.info("测试fallback------");
        CommonResult result =
         restTemplate.getForObject("http://nacos-payment-provider/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没有对应的记录，空指针异常！！！");
        }
        return result;
    }

    //兜底应急fallback方法handlerFallback
    public CommonResult handlerFallback(@PathVariable Long id,Throwable e){
        Payment payment = new Payment(id,"null");
        return new CommonResult(444,"兜底应急fallback方法handlerFallback," +
                "异常内容"+e.getMessage(),payment);
    }

    //blockHandler的限流异常处理
    public CommonResult blockHandler(@PathVariable("id") Long id, BlockException blockException){
        Payment payment = new Payment(id, "null");
        return new CommonResult(445,"blockHandler-sentinel限流处理，" +
                "无此流水，blockException："+blockException.getMessage());
    }
    //openfeign
    @Resource
    private PaymentService paymentService;
    @GetMapping(value = "consumer/paymentSQL/{id}")
    public CommonResult paymentSQL(@PathVariable("id") Long id ){
        return paymentService.paymentSQL(id);
    }
}

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

看是否自动降级：关闭所有的微服务提供者9003和9004，然后测试：http://localhost:84/consumer/paymentSQL/1