RPi3 as Zigbee/MQTT-Gateway, mirror to RPi4, keep both Units able to take over Control

Hey Folks,

to make my HomeAssistant more robust/redundant, i developed an Idea i would love to share and hear your Thoughts.
Basically, i want to operate all deconz/mqtt-Devices via a stripped-down HA-Instance on an older RPi3, basically like a “Gateway”. GUI-Operations still takes place on my “Main” Instance.

  • If the Main Instance fails, all switches/automations remain functional, as they take place on the Gateway.
  • If the Gateway Instance fails, i still can plug the Connbee-Stick into the Main Unit, and have everything working.
  • Both Instances can watch each others, and alert if one becomes unavailable.

Given: All my Entities are already organised and operated by Helpers. This is what i think of:

  1. Hook up the old RaspberryPi3 as Gateway with a Basic HA-Instance. Import DeConz, MQTT and Automations from my actual Main HA-Instance.
    Now all basic Light/Switches/Automations are operated via the Gateway

  2. Expose all (wanted) Entities via GitHub - custom-components/remote_homeassistant: Links multiple home-assistant instances together to the Main HA-Instance

  3. Add all (to the Main Instance) mirrored Entities to the corresponding Helper/Groups, so every Helper consists of an unavailable Device, and an available one.
    Light Group “Bathroom Bulb”
    light.tradfri_01 (unavailable)

  4. Backup the Main Unit (HomeAssistant, DeconZ and Remote Homeassistant) and import to the Gateway Unit
    On the “Gateway” it will look like this:
    Light Group “Bathroom Bulb”
    gatewayprefix.light.tradfri_01 (unavailable)

From now on, it doesn’t matter if a Device is operated by the Main Instance or the Gateway.
Of Course, whenever i add another Device/Entity, i have to “PingPong” the Backups (repeat Step 2-4)

What do you Guys think - will it generally work?
If its stable it is a Fallback/Backup-Strategy. If not it is another Point-Of-Failure. What would it be more likely? :slight_smile:
Would you expect a Downside i have overlooked?