Formal Modelling and Analysis of Distributed Storage Systems

Distributed storage systems are nowadays ubiquitous, often under the form of multiple caches forming a hierarchy. A large amount of work has been dedicated to design, implement and optimise such systems. However, there exists to the best of our knowledge no attempt to use formal modelling and analysis in this field. This paper proposes a formal modelling framework to design distributed storage systems, with the innovating feature to separate the various concerns they involve like data model, operations, placement, consistency, topology, etc. A system modelled in such a way can be analysed through model-checking to prove correctness properties, or through simulation to measure timed performance. In this paper, we define the modelling framework and then focus on timing analysis. We illustrate the latter aspect on a simple yet realistic example, showing that our proposal has the potential to be used to make design decisions before the real system is implemented.