OH3: MQTT System Broker Connection vs MQTT Broker Thing

Hi all,

I’ve been a long-time user of OH1 and never got around to migrating to OH2 (was never sure whether to go with text based config or UI based) but now OH3 is out it seems like a good time to step into the future…

One thing that’s confused me though is in the setup of the MQTT broker. I added the binding and created an MQTT Broker Thing and input all the settings, but then I noticed on the Administration/Settings page that there was a menu item under ‘Other Services’ called ‘MQTT system broker connection’ in which I could also add a Broker Host name/IP.

I don’t understand what this MQTT system broker connection is and whether or not I need to configure it, or is having the Thing sufficient? Or, conversely do I even need the Thing if I’ve added a system broker connection?

Note, I’ve done some reading of other posts and I think this is different from the MQTT embedded broker. For clarity, my MQTT broker runs on another machine and I do not need the embedded broker. I’m pretty sure the system broker connection is different as it asks for an host name/IP, which wouldn’t be needed for the embedded broker (I assume).

Thanks in advance,


It’s different in that it is a Thing trhat would allow openHAB to “back door” communicate with the embedded broker for admin purposes. It’s not a broker of itself. You don’t want one at all.