IoT SIG - 2020-08-25


  1. Martin Kollaard

    hi! :)

  2. debacle

    Hi!

  3. MattJ

    Howdy!

  4. debacle

    I invited Martin Kollaard to this MUC, because he lets "things" talk XMPP and I'm curious as a cat to learn about it ;-)

  5. Martin Kollaard

    Yes, mostly it are computer btw, but doing different things. Mostly it are narrowcasting screens in supermarkets across the country :)

  6. Martin Kollaard

    some versions ago it did check every 30 minutes if it is running the latest content, but we wanted to make changes realtime. so we needed a way that makes a stable connection between backend and device.

  7. debacle

    and this is realised via bots in MUCs?

  8. debacle

    or direct chat messages between bots?

  9. debacle

    Martin Kollaard ^

  10. Martin Kollaard

    direct messages

  11. Martin Kollaard

    it started with displays with prices on it, this needs to be able to update fast when there is a wrong price on it :)

  12. Martin Kollaard

    but slowly we moved everything to it

  13. debacle

    doesn't that sound like a perfect fit for PubSub?

  14. Martin Kollaard

    Most of devices do not use the same content, so it was easier not using pubsub

  15. debacle

    sure, makes sense!

  16. Martin Kollaard

    difterent per supermarket, and different per area in supermarket.

  17. Martin Kollaard

    Now we just send json in messages. But I guess it was also possible to use just send stanzas with data or use rpc model.

  18. debacle

    Martin Kollaard "XEP-0335: JSON Containers"? This is what we will use in my company, but over PubSub.

  19. Martin Kollaard

    ah I did not know that one, is that only for over pubsub?

  20. Martin Kollaard

    oh can also be used in a iq, ok nice :)

  21. Martin Kollaard

    why is it deferred :(

  22. MattJ

    Things get deferred due to inactivity

  23. MattJ

    It can be revived if there is interest in it, and if there are enough implementations and feedback from community members, it can get advanced to the next stage

  24. MattJ

    (from which it will never become deferred)

  25. Martin Kollaard

    ok :)

  26. SouL

    > sure, makes sense! Why?

  27. MattJ

    I guess because pubsub is for broadcasting data to multiple entities, but if you just have a single subscriber then you may as well send directly to them

  28. MattJ

    pubsub would have the nice feature that it can persist the data and if you needed to e.g. replace the device, it could fetch the latest published data automatically

  29. MattJ

    and would also solve for any connection reliability issues without needing to resort to MAM

  30. Martin Kollaard

    offcourse you can create a pubsub per player, but that is a overhead I think :P

  31. debacle

    you could use PEP btw. if every thingy has their own JID, but the thingy owns the node and must give publish permission on PEP - is this even possible?

  32. MattJ

    Pretty sure you can affiliate other entities with your PEP service, though I've never seen it done

  33. MattJ

    and obviously the server can always do anything