On context-independent and context-aware cloud services substitutability verification

摘要

The composition of web services in cloud computing allows making them cooperative in order to satisfy a client request. However, the substitution of one of these services by another must ensure the proper functioning of the new composition. Hence there is a need to develop adequate methods to verify the services substitution. In this aim, we propose, in the present paper, two verification methods. The first one deals with context-independent substitution and sets if a web service can substitute another one. The second one focuses on context-aware substitution and decides the substitutability of web services in a specific composition. These methods use open coloured Petri net (OCNets) as a formal framework for modelling web services and their composition in cloud computing. This model allows the structural analysis of web services' interfaces. For the behavioural verification, we use services automata, which allow capturing OCNets' behaviour and checking its preservation.