Implementation and evaluation of the last will primitive in a semantic information broker for IoT applications

Distributed loT applications in smart cities and mobile scenarios constantly face challenges due to intermittent connectivity. The temporary unavailability of one or more agents in cooperative applications, may introduce many sources of failures like, for example, the lack of synchronization or the absence of a needed module in a complex service provision. In this article, we discuss about and describe the implementation of a last will (LW) primitive for a semantic information broker used to manage the central knowledge base of a smart city scenario. The semantic LW plays a crucial role in increasing the overall reliability and resiliency to connectivity failures. This primitive exhibits higher expressivity and flexibility compared to the MQTT LW, good responsiveness and a negligible static impact on the performance.