A framework for Internet of Things search engines engineering

The content of the Internet of Things (IoT), notably sensor data and virtual representation of physical devices, has been increasingly delivered via Web protocols and available on the World Wide Web (WWW). Internet of Things Search Engine (IoTSE) systems are catalytic to utilize this influx of data. They enable users to discover and retrieve relevant IoT content. While a general IoTSE system-the next 'Google'-is beyond the horizon due to the vast diversity of IoT content and types of queries for them, specific IoTSE systems that target subsets of query types and IoT infrastructure are feasible and beneficial. A component-based engineering approach, in which prior IoTSE systems and research prototypes are reassembled as building blocks for new IoTSE systems, could be a time-and cost-effective solution to engineering IoTSE systems. This paper presents the design, implementation, and evaluation of a framework to facilitate a component-based approach to engineering IoTSE systems. As an evaluation, we developed eight IoTSE components and composed them into eight proof-of-concept IoTSE systems, using a reference implementation of the proposed framework. An analysis on Source Line of Code (SLOC) revealed that the complexity handled transparently by the IoTSE framework could account for over 90% of the code base of a simple IoTSE system.