Dynamic evolution mechanism for trustworthy software based on service composition

This paper is concerned with trustworthy software constructed through service composition and is especially emphasizes guaranteeing the trustworthiness of networked software through dynamic evolution of composite services. First of all, a set of evolution operations preserving soundness of composite services is proposed so as to avoid the complex verification process. Second, a composite service evolution method with availability guarantee is provided, the main idea of which is to create redundant execution path to improve the availability of a composite service. Third, to deal with runtime instances after dynamic composite service evolution, a live instance migration algorithm is designed to support the correct evolution enforcement. Finally, a composite service execution engine supporting dynamic evolution is developed and the effectiveness of the proposed method is showed through a set of experiments.