A Self-Stabilizing Publish/Subscribe Middleware for IoT Applications

This article presents a middleware that provides a communication and data dissemination infrastructure suitable for the operation environment of the Internet of Things (IoT). The middleware realizes the channel-based publish/subscribe paradigm that has been identified as a valid means to asynchronously disseminate data in IoT applications. The novelty lies in the routing algorithm PSVR that greatly reduces the path lengths to deliver publications and its suitability for scenarios with a high subfluctuation rate. The middleware is self-stabilizing and eventually provides safety and liveness properties such as the guaranteed delivery of all published messages to all subscribers and the correct handling of subscriptions and unsubscriptions, while no error occurs. The evaluation of the middleware, based on simulations and a real deployment, shows that it has a low memory footprint and scales well with the number of nodes.