服务熔断、降级--Hystrix

1.导入依赖

2.添加注解

在方法上或者Controller中的路径上添加注解@HystrixCommand(fallbackMethod = “dept_TimeoutHandler”）

3.激活熔断器功能

@SpringBootApplication
@EnableEurekaClient //开启 Eureka 客户端功能
@EnableCircuitBreaker //激活熔断器功能<---------
public class MicroServiceCloudProviderDeptHystrix8004Application {
    public static void main(String[] args) {
        SpringApplication.run(MicroServiceCloudProviderDeptHystrix8004Application.class, args);
    }
}

降级--------

1.配置

feign:
  hystrix:
    enabled: true #开启客户端 hystrix

2.降级

@Component
@FeignClient(value = "MICROSERVICECLOUDPROVIDERDEPTHYSTRIX", fallback = DeptHystrixFallBackService.class)
public interface DeptHystrixService {
    @RequestMapping(value = "/dept/hystrix/ok/{id}")
    public String deptInfo_Ok(@PathVariable("id") Integer id);
    @RequestMapping(value = "/dept/hystrix/timeout/{id}")
    public String deptInfo_Timeout(@PathVariable("id") Integer id);
}

Dashboard流监控

1，依赖

<!--hystrix-dashboard 监控的依赖-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix-dashboard</artifactId>
        </dependency>

2.开启注解
@EnablehystrixDashboard

3.增加一个Servlet

 @Bean
    public ServletRegistrationBean getServlet() {
        HystrixMetricsStreamServlet streamServlet = new HystrixMetricsStreamServlet();
        ServletRegistrationBean registrationBean = new ServletRegistrationBean(streamServlet);
        registrationBean.setLoadOnStartup(1);
        registrationBean.addUrlMappings("/actuator/hystrix.stream");//访问路径
        registrationBean.setName("hystrix.stream");
        return registrationBean;
    }

监控依赖

spring-cloud-start-actuator