Reasoning About Exception Flow at the Architectural Level

An important challenge faced by the developers of fault- tolerant systems is to build reliable fault tolerance mechanisms. To achieve the desired levels of reliability, mechanisms for detecting and handling errors should be designed since early phases of software development, preferably using a rigorous or formal methodology. In recent years, many researchers have been advocating the idea that exception handling-related issues should be addressed at the architectural level, as a complement to implementation-level exception handling. However, few works in the literature have addressed the problem of describing how exceptions flow amongst architectural elements. This work proposes a solution to this problem to support the early detection of mismatches between architectural elements due to exceptions. Moreover, it makes it possible to validate whether the architecture satisfies some properties of interest regarding exception flow before the system is actually built. Our solution proposes a model for describing the architectural flow of exceptions which is precise and automatically analyzable by means of a tool.