Abstract: A method performed at a data broker in a publish/subscribe messaging system, the method comprising establishing, in accordance with a publish/subscribe messaging protocol, a respective connection with each of one or more publish/subscribe messaging clients, after the establishing, receiving at the data broker system from a system client a deployment instruction instructing the data broker system to deploy a behavior model for modifying an operation of the data broker system, and in response to receiving the deployment instruction, processing control packets received at the data broker from the one or more publish/subscribe messaging clients in accordance with the behavior model.

Abstract: A method performed at a data broker comprises receiving from a subscriber client a request for a subscription for sensor data transmitted by a sensor client, the request in accordance with a publish/subscribe messaging protocol, receiving sensor data from the sensor client, the sensor data published by the sensor client in accordance with the messaging protocol, and determining, in dependence on the sensor data and a current state of a state machine associated with the sensor client, whether the sensor data is to be subject to subscription processing. The method further comprises determining, in dependence on the receipt of the sensor data and the current state of the state machine, an updated state for the state machine, updating the state machine to the updated state, and if the data is to be subject to subscription processing, forwarding the data to the subscriber client in accordance with the messaging protocol.