[Feature] Connect to multiple MQTT brokers/base topics

[GerSant]

Problem description

I have 2 zigbee2mqtt instances running, each use a different base topic

Suggested solution

Will be great the ability of declare more than one "mqtt" sentence in the platform

Alternative solutions

Have another Homebridge instance running the z2m plugin with the 2nd zigbee2mqtt base topic

Additional context / information

No response

[itavero]

Just out of curiosity, what's the reason for having multiple Zigbee2MQTT instances?

Would you be able to solve this with child bridges?

[GerSant]

There is a big problem with the Tuya ZY-M100-S accessories, those device spams the Zigbee Network with 10 status updates messages (with any changes) per second. This behaviour causes poor performance, response times, in the zigbee network affecting other devices.
The current workaround is create a second Zigbee Networks (in other channel with other PAN ID) for this shitty devices.

You can found here
Koenkk/zigbee2mqtt#19045

The 2nd reason is, for some big networks (more than 150 devices) is recommended to split in 2 separate Zigbee Networks.

[itavero]

So, did the Child Bridge approach work for you?
If so, let me know, then we can close this issue.

[dmatik]

@itavero
It definitely worked for me.
I also have 3 separate instances of Z2M at my home (1 for each floor).
However it could be nice to be able to give those child bridges different names, since it is hard to tell who is who there on the child bridges list.

[FromTheCToTheG]

Same for me - I also have 3 instances of Z2M, also one for each separate floor.

Thank you for your good advice, I also managed to create a separate child bridge for every instance/mqtt topic. However, I didn't manage to do so via the WebUI (is there any way at all?), so I did it through editing the JSON config.
For naming the different instances, you can then use the configuration-dropdown of the child bridge and enter a name there, or enter a name directly in the JSON like:
{
"mqtt": {
"base_topic": "zigbee2mqtt-groundfloor",
"server": "mqtt://broker.ip:1883",
"user": "username",
"password": "userpassword",
"reject_unauthorized": false,
"keepalive": 60,
"version": 4,
"disable_qos": false
},
"defaults": {
"exclude": false
},
"exclude_grouped_devices": false,
"platform": "zigbee2mqtt",
"_bridge": {
"username": "FF:FF:FF:1A:FF:F3",
"port": 53420,
"name": "Z2M Ground Floor"
}