QoR-Driven Resource Selection for Hybrid Web Environments

In the Web of Things (WoT) context, an increasing number of objects provide functions as RESTful services (resources), that can be composed with other existing resources, to create value-added processes (compositions). However, to form a composition, selecting the suitable resources is becoming more challenging, due to: (1) the growing number of resources providing identical functions, which calls for the use of Quality of Resource (QoR) to distinguish between them, and (2) the transient nature of resource availability as a result of objects’ sporadic connectivity in the WoT environments. In this chapter, we present a QoR-driven resource selection approach that forms i-compositions (with i ∈N∗) offering different implementation alternatives. This is done using a selection strategy adaptor that considers QoR constraints and Inputs/Outputs matching of related resources, as well as resource availability and users’ different needs (e.g., optimal compositions having the highest scores, and optimistic compositions having acceptable scores but obtained in more satisfactory delays). Analysis are made to evaluate our resource quality model against existing ones, and experiments are conducted in different environments setups to study the performance of our work.