Limit on the number of MQTT server connection in MQTT Transmission

Ignition Modules
1

I am sending data to Azure Event Grid using MQTT transmission. Can I connect MQTT Modules to Azure Event Grid - MQTT Modules for Ignition 8.1 - Confluence

I have used a single transmitter where the folder structure results in 110 unique edge node ids. Thereby my single server connection seamlessly results in 110 MQTT clients. Since they share the same server, they must have the same username.

On to the problem. Azure Event Grid uses the “username” in the connect packet to match to the Event Grid Client “authentication name”. It then uses the MQTTclientID to create a session/” MQTT connection”. The problem is that in the event grid has a hard limit of 100 client sessions per authentication name- My setup gives 110.

Workaround:

A workaround is to create 110 server connections and 110 transmitters in ignition by code.

My questions:

  • Is there a way one single server connection in MQTT transmission can have different username for each of its clients?
  • Regarding the workaround, from an Ignition backend/performance perspective is defining 110 MQTT server connections with 1 client each, the same as 1 server connections with 110 MQTT clients?
2

Hello karl,

I will pass these questions along to one of my team members and reply early Monday or Tuesday.

Dan

1 Like
3

On these two questions:

Is there a way one single server connection in MQTT transmission can have different username for each of its clients?

Not currently. I should note this can be scripted to reduce the effort in creating this config via the Web UI.

Regarding the workaround, from an Ignition backend/performance perspective is defining 110 MQTT server connections with 1 client each, the same as 1 server connections with 110 MQTT clients?

It’s not quite the same. There is base layer of code that will get created 110 times instead of one. But, it isn’t a huge amount of overhead.

Is there a reason you can’t have fewer clients?