I'd like to share a design sub-optimization issue related to the Mosquitto broker implementation pattern where no parallelism is used, and ask for any opinions and insights about it.
We run the mosquitto broker inside a network node that plays the central (or coordinator) role of the given network. Every systems protocols runs on top of the MQTT and uses the central node and this network is self contained, it doesn't need external internet access to proper operate.
The Mosquitto broker running in the central node have a bridge connection to a remote broker for low priority data transfer.
What I see as an issue, in our use case, is that under very poor internet connection, the bridge takes considerable long time to connect (and sometimes it never connects) turning the broker unresponsive during this period, which will bring all local and high priority services to degradation.
What do you guys think of that?