We are currently running a Mosquitto broker on a Digital Ocean droplet. We currently have more than 2,000 connections and the number is increasing rapidly. I'm wondering how we might scale the number of connections we can accept. It would be nice at least in the short term to stick with Mosquitto as it has been performing robustly for us.
It seems like there are ideas about using HA Proxy with several mosquitto brokers bridged and a sync broker, for example as explained here:
Has anybody actually tried this? Does this require websockets for HA Proxy to work? it seems like these could all run on the same machine in different threads? I'm on Digital Ocean and I'm not sure how this plays out with their virtual machines and virtual cores (of which it appears there is only 1 core but it's virtual so what that means is not obvious to me in terms of performance).
This mailing list thread where Michael Laing claims to have an experimental solution using Mosquitto caught my eye. Whatever became of that?
Since I was not on the mailing list at the time of that discussion I don't have any contact info for him.
I could switch away from Mosquitto but would rather not have to change the firmware in our devices that are already out in the field. As part of our framework we used the client prefix for accepting connections, and I'm not seeing other brokers supporting that. We also used a non-standard port for the SSL/TLS connections and I'm not seeing how 3rd party services like CloudMQTT and AWS IoT could support that.
For us a concurrent short term solution to get us by (implemented with less than 20 hours of research and work) and a longer term solution for a year or so down the road would be a sensible way to go.
Any thoughts or advice is welcome.
