I’m trying to qualify Ignition for our usage, and we need to use our MQTT Server JoramMQ.
So i’m testing MQTT engine to make the bridge between MQTT and Ignition.
It works very well with sparkplug namespace.
However, when I create a custom namespace, listening to a topic that contains “retain” values, then the connection is broken up every minutes, and it basically break all MQTT features.
Tinkering around, I noticed that the MQTT server is sending the list of retain value before answering the SUBACK, and it’s ok by MQTT 3.1.1 specifications. (cf. L964-965 “The Server is permitted to start sending PUBLISH packets matching the Subscription before the Server sends the SUBACK Packet.”)
When I’m trying a custom namespace without retain, then there is no issue.
So I can only conclude that the MQTT Engine is not handling correctly the possibility to receive PUBLISH packets before receiving the SUBACK.
Did someone has a similar experience ?