Comment by this_user

Having recently used MQTT for a project, I can't say that I'm a huge fan. There are a lot of options in the protocol where it's not immediately clear what they do and why they are important, or in what combination they need to be used to make sure things work as intended, and the documentation is often not great at explaining. Part of this may also be on the Eclipse Mosquitto Python client that I had been using. I took me several days to figure out that the client was running into a race condition on a slower system that resulted in subscriptions to topics silently being ignored which caused the associated callbacks to malfunction despite following their documentation 100%. Overall, this has been one the messiest experienced I have ever had with a protocol, certainly one that isn't that old.