We need to build a server that can communicate with some embedded devices running a variant of Android. We need to be able to send commands to the device, and receive a response. A simple command might be asking the device for it's status. We won't have HTTP, so we need to have the client/device establish a connection with the server.
We were considering using MQTT as it has a lot of nice properties (QoS, lightweight, built for IoT), but it doesn't natively support a request response workflow.
We have considered building RPC on top of MQTT, but before we do I just wanted peoples thoughts on the matter. Would Websockets, WAMP, ZeroMQ be a better approach?
Q1: Do we even need RPC?
Q2: Is there an approach to building systems where I always send async type messages and still provide a good user experience?
Q3: Any examples?
Looking for implementation examples and hands on experience of building an IoT communication system beyond a toy example with a single device.