(6)springcloud使用熔断器防止服务雪崩Hystrix

红太狼 2023-05-29 05:10 242阅读 0赞

一.ribbon中使用熔断器

# 在(4)springcloud创建服务消费者（Ribbon） #

[https://blog.csdn.net/yanyf2016/article/details/102895149][https_blog.csdn.net_yanyf2016_article_details_102895149]

在pom.xml中增加依赖

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

在WebAdminRibbonApplication中增加注解@EnableHystrix开启熔断器

在AdminService增加一个注解@HystrixCommand和一个方法

@HystrixCommand(fallbackMethod = "hiError")
        public String sayHi(String message) {
            return restTemplate.getForObject("http://hello-spring-cloud-service-admin/hi?message=" + message, String.class);
        }
    
        public String hiError(String message) {
            return String.format("Hi your message is : %s but request bad", message);
        }

重启项目，将8762和8763服务关掉，再次访问8764看效果

![20191104145801300.png][]

二、在feign中使用熔断器  目录结构：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbnlmMjAxNg_size_16_color_FFFFFF_t_70][]

Feign自带熔断器，但默认是关闭的，需要再配置文件中打开

(5)springcloud创建服务消费者（feign）

[https://blog.csdn.net/yanyf2016/article/details/102895844][https_blog.csdn.net_yanyf2016_article_details_102895844]

application.yum中加

feign:
      hystrix:
        enabled: true

实现AdminFeignService

import com.itheima.hello.spring.cloud.web.admin.feign.service.AdminFeignService;
    import org.springframework.stereotype.Component;
    
    
    @Component
    public class AdminServiceHystrix implements AdminFeignService {
    
        @Override
        public String sayHi(String message) {
            return String.format("Hi your message is : %s, but request bad", message);
        }
    }

接口中加 fallback = AdminServiceHystrix.class

@FeignClient(value = "hello-spring-cloud-service-admin", fallback = AdminServiceHystrix.class)
    public interface AdminFeignService {
    
        @GetMapping("hi")
        public String sayHi(@RequestParam(value="message") String message);
    }

![20191104151002650.png][]

[https_blog.csdn.net_yanyf2016_article_details_102895149]: https://blog.csdn.net/yanyf2016/article/details/102895149
[20191104145801300.png]: https://img-blog.csdnimg.cn/20191104145801300.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbnlmMjAxNg_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20191104152814953.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbnlmMjAxNg==,size_16,color_FFFFFF,t_70
[https_blog.csdn.net_yanyf2016_article_details_102895844]: https://blog.csdn.net/yanyf2016/article/details/102895844
[20191104151002650.png]: https://img-blog.csdnimg.cn/20191104151002650.png