Learning blog: [SpringCloud] Hystrix service downgrade

The fuse is on the server side, a certain service times out or is abnormal, causing a fuse, and a backup solution (fuse) is provided if there is a problem

The downgrade is on the client side, considering the website request load, and temporarily closing some interfaces. After a service is blown or closed, the service will not be called. At this time, the client can prepare a FallbackFactory and return the default value

project structure

Enable annotations in the API interface

@FeignClient(value = "http://SPRINGCLOUD-PROVIDER-DEPT",fallbackFactory = DeptClientServiceFallbackFactory.class)

Implementation class

//降级
@Component
public class DeptClientServiceFallbackFactory implements FallbackFactory {
    
    
    @Override
    public DeptClientService create(Throwable cause) {
    
    
        return new DeptClientService() {
    
    
            @Override
            public Dept queryById(Long id) {
    
    
                return new Dept()
                        .setDeptno(id)
                        .setDname("id=>"+id+"无对应信息,降级处理,该服务已关闭")
                        .setDb_source("无数据");
            }

            @Override
            public List<Dept> queryAll() {
    
    
                return null;
            }

            @Override
            public boolean addDept(Dept dept) {
    
    
                return false;
            }
        };
    }
}

---

Enable downgrade in project structure application.yml

#开启降级
feign:
  circuitbreaker:
    enabled: true

Normal access

There is a fuse mechanism and the server is not closed

After the degraded service is enabled, close the server

The interface is closed and the service cannot be called