What You Always Wanted to Know About Model Checking of Fault-Tolerant Distributed Algorithms

Abstract

Distributed algorithms have numerous mission-critical applications in embedded avionic and automotive systems, cloud computing, computer networks, hardware design, and the internet of things. Although distributed algorithms exhibit complex interactions with their computing environment and are difficult to understand for human engineers, computer science has developed only very limited tool support to catch logical errors in distributed algorithms at design time. In the last two decades we have witnessed a revolutionary progress in software model checking due to the development of powerful techniques such as abstract model checking, SMT solving, and partial order reduction. Still, model checking of fault-tolerant distributed algorithms poses multiple research challenges, most notably parameterized verification: verifying an algorithm for all system sizes and different combinations of faults. In this paper, we survey our recent results in this area which extend and combine abstraction, partial orders, and bounded model checking. Our results demonstrate that model checking has acquired sufficient critical mass to build the theory and the practical tools for the formal verification of large classes of distributed algorithms.