MQTT is widely used in IoT when it comes to exchanging application data between the end device and the host service. The publish-subscribe model makes it easy to use: no handshaking, negotiating etc (at least above the MQTT protocol layer). It's primarily geared towards data-producers being able to distribute their data easily to consumers.
However, when it comes to a central server wanting to configure settings on an end device, I'm not sure that the model is very suitable. The server will want to send a command to the device and wait for a response back (e.g. read a specific setting, wait for response), which doesn't really suit MQTT's publish-subscribe model.
I was wondering whether there are any existing protocols that are geared towards send and receiving commands and configuring remote devices?