IoT WebSockets acknowledgments across several channels

[Former Member]

I have a question in regard to setting up IoT service for communication amongst several devices, more specifically the MQTT over WebSockets.

I want to know if it is possible in any way to overcome the limitation of the acknowledgment service that "Acknowledgments are sent from the MMS to the device over the same WebSocket connection that is used to send data from the device to the MMS".

I would like to receive the acknowledgment in other established WS connections as well so that they could react to the changes in the DB accordingly. I have two UI5 apps and a Rasperry Pi used in this project and the communication between them was planned over the WS channels on IoT, to ensure reactions on all connected devices.

A dirty workaround on my mind now is to make a loop requesting information to the DB in intervals, but that would cause a lot of unneeded calls to the DB, so is there a better way to implement it?

FYI, the guide where the acknowledgment issue is stated:

https://help.hana.ondemand.com/iot/frameset.htm?e12d1429ddcb469ebed59746b64e16ae.html

[WouterLemaire]

I don't think it's possible for the moment. I've been searching for this too but also ended up with a loop for requesting information from the DB in intervals.. If you find a better solution, please let me know 🙂

Regards,

Wouter

[anton_levin]

Hello Janis, to realize it, you would need to make use of the native MQTT over TCP Data Service [1] but be aware that you have to host your MQTT broker yourself, since it is not a part of the MMS.

Regards, Anton

[1] https://help.hana.ondemand.com/iot/frameset.htm?a9764708d68b43e59c823218d1aa6346.html

[Former Member]

Hello, Anton!

That is what I had in mind as well, but I hoped there is another way to do it without the hassle of hosting the MQTT, but apparently I will have to try this approach today.

Br,

Janis