Analysing and determining substitutability of different granularity Web services

Abstract

Substitutability of Web service is the key aspect for ensuring reliability of Web service-oriented software. Along with more large and coarse granularity services appear across the Internet continuously, it has become a new challenge that how to determine the substitutability between different granularity services. In this paper, we propose the notion of interface inverted dependence to reveal all functions and business logic of large granularity services. A formal model is bulit by extending the Martin-Löf's type theory. The model can clearly describe both large and small granularity services from three aspects: syntax, semantics, and behaviour. Based on the formalization, we introduce the notions of substitutability between different granularity services with different stringency through considering the context of services. In order to judge the substitutability, a mechanism based on subtyping theory is proposed. At last, the case study is given to show the effectiveness of the proposed substitutability.

Keywords:

• large granularity Web service
• substitutability
• type theory
• verification

2000 AMS Subject Classification:

• 03B70

Acknowledgements

This work is supported by Zhejiang Provincial Natural Science Foundation of China (No. LY12F02003), National High-Tech Research and Development Plan of China (No. 2012BAH24B00) and Natural Science Foundation of China (No. 61100043).