1.背景
在使用spring cloud gateway时,服务的上下线可能会没那么及时,这样就会导致在进行业务服重启时会出现部分用户请求接口出现503,服务不可用的情况。
nacos-client版本:
1.4.1
spring-cloud-starter-alibaba-nacos-discovery版本:
2.2.5
2.实现
在spring-cloud-starter-alibaba-nacos-discovery中并未找到获取服务注册时进行会发布的事件,所以去nacos-client中找到了InstancesChangeEvent
事件,并且发现了事件的发布订阅关系
在 类中
this.notifier = new InstancesChangeNotifier();
NotifyCenter.registerToPublisher(InstancesChangeEvent.class, 16384);
NotifyCenter.registerSubscriber(notifier);
至此,我们找到了实现方案:
模仿InstancesChangeNotifier进行自己服务实例变化处理
@Component
@Slf4j
public class NacosServiceInstanceChangeNotifier extends Subscriber<InstancesChangeEvent>{
@PostConstruct
public void registerToNotifyCenter(){
NotifyCenter.registerSubscriber(this);
}
@Override
public void onEvent(InstancesChangeEvent instancesChangeEvent) {
log.info("监听nacos的服务实例变化情况:{}", JSON.toJSONString(instancesChangeEvent));
}
@Override
public Class<? extends Event> subscribeType() {
return InstancesChangeEvent.class;
}
}
当服务上下线时:
服务上线:
监听nacos的服务实例变化情况:{"clusters":"","groupName":"DEFAULT_GROUP","hosts":[{"clusterName":"DEFAULT","enabled":true,"ephemeral":true,"healthy":true,"instanceHeartBeatInterval":5000,"instanceHeartBeatTimeOut":15000,"instanceId":"192.168.0.188#15061#DEFAULT#DEFAULT_GROUP@@client-api-service","ip":"192.168.0.188","ipDeleteTimeout":30000,"metadata":{"":"SPRING_CLOUD","-time":"1680507089247"},"port":15061,"serviceName":"DEFAULT_GROUP@@client-api-service","weight":1.0}],"serviceName":"DEFAULT_GROUP@@client-api-service"}
服务下线:
监听nacos的服务实例变化情况:{"clusters":"","groupName":"DEFAULT_GROUP","hosts":[],"serviceName":"DEFAULT_GROUP@@client-api-service"}
3. 未完待续
- 如何刷新负载均衡器的缓存
- 动态路由如何刷新