A chemical evolutionary mechanism for instantiating service-based applications

ervice Oriented Architecture (SOA) has become the de facto paradigm for the Internet of Services (IoS), i.e. a virtual space where information and content is stored, exchanged and manipulated by software and human entities through services. In this scenario, a Service Based Application (SBA) is a composition of a number of possibly independent services, that is software programs or interfaces for human entities connected through the network and performing a set of functionalities whose integration should fulfil the requirement of the SBA end-user. Therefore it becomes necessary to organize compositions of services on demand in response to dynamic requirements and circumstances. At this end the process of selecting service instances matching an SBA requested under certain conditions is modelled as an evolving chemical process that can react to environmental changes as they occur, so providing adaptability to non-functional characteristics changes. The chemical metaphor allows to approach the composition of services as a decentralized and incremental aggregation mechanism governed by local rules such that environmental changes affecting any part of SBA may be processed at any time.