Re: [hono-dev] Device online status API for Command And Control

[Marc Pellmann <pellmann@xxxxxxxxx>]

Hi Karsten,

2.) Delivery guarantees:

 

We all agreed IMHO that we want to guarantee the delivery of notifications when devices are coming online (a lot of further aspects of C&C rely on that).

And have a best effort for the disconnect of a device.

 

But what does that mean in particular regarding the guaranteed notification?

 

I am not sure if there is any good value if we deliver this notification with QoS 1 (like events),

since the protocol adapter receiving an acknowledgement would not do much with it. If the delivery would be acknowledged with "no success", it would still deliver e.g. telemetry data.

 

So to me the guarantee to send the online notification means "we will send the notification, but we do not treat a not successful delivery".

 

So it looks to me like we send telemetry data - if no one listens to this API or the notification is somehow lost, there would be no consequences except for that no command could be sent.

WDYT?

a retry feature in the adapter might be a good idea, depending on the deployment - this would be possible with QoS 1.