Nacos 2.X client need add async redo feature for failed register/subscribe service.

[KomachiSion]

Is your feature request related to a problem? Please describe.

In nacos 2.X client, If register or subscribe service failed, client will throw NacosException out to caller, and help caller to stop the application start.

But some of framework. such as dubbo, will catch the exception and just ignore it then go ahead to do, which will cause application maybe miss the service they register or subscribe.

And we think nacos client throw the NacosException is not problem, but client should add a async redo feature for these register/subscribe failed services.

Describe the solution you'd like
Add a common redo task feature for all service, include register/unregister/subscribe/unsubscribe/reconncetion

[KomachiSion]

I plan to implement this feature by wrapper client cache with two status. After call grpc, client should update the cache status. And use another thread to do redo according to the status.

[Russell4115]

Thanks