注:本篇文章主要参考周阳老师讲解的cloud进行整理的!
1、需求说明
cloudalibaba-consumer-nacos-order83 通过OpenFeign调用 cloudalibaba-provider-payment9001
1、 83 通过OpenFeign调用 9001微服务,正常访问OK
2、 83 通过OpenFeign调用 9001微服务,异常访问error
访问者要有fallback服务降级的情况,不要持续访问9001加大微服务负担,但是通过feign接口调用的又方法各自不同,如果每个不同方法都加一个fallback配对方法,会导致代码膨胀不好管理,工程埋雷…/(ㄒoㄒ)/~~
3、 public @interface FeignClient
通过fallback属性进行统一配置,feign接口里面定义的全部方法都走统一的服务降级,一个搞定即可。
4、 9001微服务自身还带着sentinel内部配置的流控规则,如果满足也会被触发,也即本例有2个Case
4.1、 OpenFeign接口的统一fallback服务降级处理
4.2、 Sentinel访问触发了自定义的限流配置,在注解@SentinelResource里面配置的blockHandler方法。
2、程序解耦
2.1、前述参考
2.2、本例说明
3、编码步骤
3.1、启动nacos服务器8848
startup.cmd -m standalone
3.2、启动Sentinel服务
java -jar sentinel-dashboard-1.8.6.jar
3.3、修改服务提供方cloudalibaba-provider-payment9001
3.3.1、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"><modelVersion>4.0.0</modelVersion><parent><groupId>com.mui.cloud</groupId><artifactId>cloud2024</artifactId><version>1.0-SNAPSHOT</version></parent><groupId>com.mui.cloud</groupId><artifactId>cloudalibaba-provider-payment9001</artifactId><properties><maven.compiler.source>17</maven.compiler.source><maven.compiler.target>17</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><!--openfeign--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!--alibaba-sentinel--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><!--nacos-discovery--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!-- 引入自己定义的api通用包 --><dependency><groupId>com.mui.cloud</groupId><artifactId>cloud-api-commons</artifactId><version>1.0-SNAPSHOT</version></dependency><!--SpringBoot通用依赖模块--><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><!--hutool--><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId></dependency><!--lombok--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.28</version><scope>provided</scope></dependency><!--test--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>
3.3.2、修改YML
server:port: 9002spring:application:name: nacos-payment-providercloud:nacos:discovery:# 配置Nacos地址server-addr: localhost:8848sentinel:transport:dashboard: localhost:8080 #配置Sentinel dashboard控制台服务地址port: 8719 #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
3.3.3、主启动
package com.mui.cloud;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;@SpringBootApplication
@EnableDiscoveryClient
public class Main9001 {public static void main(String[] args) {SpringApplication.run(Main9001.class, args);}
}
3.3.4、PayAlibabaController
package com.mui.cloud.controller;import cn.hutool.core.util.IdUtil;
import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.dashun.cloud.entities.PayDTO;
import com.dashun.cloud.enums.ReturnCodeEnum;
import com.dashun.cloud.resp.ResultData;
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.math.BigDecimal;@RestController
public class PayAlibabaController {@Value("${server.port}")private String serverPort;@GetMapping("/pay/nacos/{id}")public String getPayInfo(@PathVariable("id") Integer id) {return "nacos registry, serverport:" + serverPort + "\t id:" + id;}@GetMapping("/pay/nacos/get/{orderNo}")@SentinelResource(value = "getPayByOrderNo", blockHandler = "handlerBlockHandler")public ResultData getPayByOrderNo(@PathVariable("orderNo") String orderNo) {// 模拟从数据库查询出数据并赋值给DTOPayDTO payDTO = new PayDTO();payDTO.setId(1024);payDTO.setOrderNo(orderNo);payDTO.setAmount(BigDecimal.valueOf(9.9));payDTO.setPayNo("pay:" + IdUtil.fastUUID());payDTO.setUserId(1);return ResultData.success("查询返回值:" + payDTO);}public ResultData handlerBlockHandler(@PathVariable("orderNo") String orderNo, BlockException exception) {return ResultData.fail(ReturnCodeEnum.RC500.getCode(), "getPayByOrderNo服务不可用,触发sentinel流控配置规则" + "\t" + "o(╥﹏╥)o");}}
3.3.5、测试
启动9001微服务测试
http://localhost:9001/pay/nacos/get/ord1024
3.4、修改cloud-api-commons
3.4.1、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"><modelVersion>4.0.0</modelVersion><parent><groupId>com.mui.cloud</groupId><artifactId>cloud2024</artifactId><version>1.0-SNAPSHOT</version></parent><artifactId>cloud-api-commons</artifactId><properties><maven.compiler.source>17</maven.compiler.source><maven.compiler.target>17</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><!--openfeign--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!--alibaba-sentinel--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><!--openfeign--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!--SpringBoot通用依赖模块--><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.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><!--hutool--><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId></dependency></dependencies></project>
3.4.2、新增PayFeignSentinelApi接口
package com.mui.cloud.api;import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.mui.cloud.resp.ResultData;
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 = PayFeignSentinelApiFallBack.class)
public interface PayFeignSentinelApi {@GetMapping("/pay/nacos/get/{orderNo}")public ResultData getPayByOrderNo(@PathVariable("orderNo") String orderNo);}
3.4.3、为远程调用新建全局统一服务降级类
package com.mui.cloud.api;import com.mui.cloud.enums.ReturnCodeEnum;
import com.mui.cloud.resp.ResultData;
import org.springframework.stereotype.Component;@Component
public class PayFeignSentinelApiFallBack implements PayFeignSentinelApi {@Overridepublic ResultData getPayByOrderNo(String orderNo) {return ResultData.fail(ReturnCodeEnum.RC500.getCode(), "对方服务宕机或不可用,FallBack服务降级o(╥﹏╥)o");}}
3.5、修改cloudalibaba-consumer-nacos-order83
3.5.1、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"><modelVersion>4.0.0</modelVersion><parent><groupId>com.dashun.cloud</groupId><artifactId>cloud2024</artifactId><version>1.0-SNAPSHOT</version></parent><groupId>com.mui.cloud</groupId><artifactId>cloudalibaba-consumer-nacos-order83</artifactId><properties><maven.compiler.source>17</maven.compiler.source><maven.compiler.target>17</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><!-- 引入自己定义的api通用包 --><dependency><groupId>com.mui.cloud</groupId><artifactId>cloud-api-commons</artifactId><version>1.0-SNAPSHOT</version></dependency><!--openfeign--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!--alibaba-sentinel--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><!--nacos-discovery--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--loadbalancer--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-loadbalancer</artifactId></dependency><!--web + actuator--><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><!--lombok--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>
3.5.2、YML
server:port: 83spring:application:name: nacos-order-consumercloud:nacos:discovery:server-addr: localhost:8848
#消费者将要去访问的微服务名称(nacos微服务提供者叫什么你写什么)
service-url:nacos-user-service: http://nacos-payment-provider# 激活Sentinel对Feign的支持
feign:sentinel:enabled: true
3.5.3、主启动
package com.mui.cloud;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 Main83 {public static void main(String[] args) {SpringApplication.run(Main83.class, args);}
}
3.5.4、业务类
package com.mui.cloud.controller;import com.mui.cloud.api.PayFeignSentinelApi;
import com.mui.cloud.resp.ResultData;
import jakarta.annotation.Resource;
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 org.springframework.web.client.RestTemplate;@RestController
public class OrderNacosController {@Resourceprivate RestTemplate restTemplate;@Resourceprivate PayFeignSentinelApi payFeignSentinelApi;@Value("${service-url.nacos-user-service}")private String serverURL;@GetMapping("/consumer/pay/nacos/{id}")public String paymentInfo(@PathVariable("id") Integer id) {String result = restTemplate.getForObject(serverURL + "/pay/nacos/" + id, String.class);return result + "\t" + " 我是OrderNacosController83调用者。。。。。。";}@GetMapping(value = "/consumer/pay/nacos/get/{orderNo}")public ResultData getPayByOrderNo(@PathVariable("orderNo") String orderNo) {return payFeignSentinelApi.getPayByOrderNo(orderNo);}}
3.5.5、启动83微服务第一次
3.5.5.1、故障现象
3.5.5.2、导致原因
springboot + springcloud版本太高导致和阿里巴巴Sentinel不兼容
3.5.5.3、解决方案
总体父工程,boot + cloud降低版本
<spring.boot.version>3.2.0</spring.boot.version> |
<spring.cloud.version>2023.0.0</spring.cloud.version> |
上面的配置暂时为本案例注释掉,版本降级一下。 |
讲解完后请恢复上述高版本保持前后配置一致,请用下面的版本替代上述 |
<spring.boot.version>3.0.9</spring.boot.version> |
<spring.cloud.version>2022.0.2</spring.cloud.version> |
再次启动成功
4、测试
-
9001正常启动后,再启动83通过feign调用
-
测试地址
- http://localhost:83/consumer/pay/nacos/get/1024
- http://localhost:83/consumer/pay/nacos/get/1024
-
sentinel流控为例,进行配置
-
http://localhost:83/consumer/pay/nacos/get/1024
-
频繁访问后触发了Sentinel的流控规则
-
9001宕机了,83通过feign调用
- 测试83调用9001,此时故意关闭9001微服务提供者,看83消费侧自动降级,不会被耗死
- 降级效果
-
最后一步
- 恢复父工程版本号,升