A Component-based Methodology to Adapt the Fault Tolerance of Distributed Protocols

Nowadays, there are many protocols able to cope with process crashes, but, unfortunately, a process crash represents only a particular faulty behavior. Handling tougher failures (e.g. sending omission failures, receive omission failures, arbitrary failures) is a real practical challenge due to malicious attacks or unexpected software errors. This paper proposes a component-based methodology allowing, for example, to take a protocol A resilient to crash failures and to add software components in order to adapt the protocol A to be resilient to more general failures than crash. On this basis, it introduces the notions of liveness failure detector and safety failure detector, two independent software components to be used by a protocol to increases its resilience respectively to liveness and safety failures of processes running the protocol. Then, the feasibility of this approach is shown, by providing an implementation of liveness failure detectors and of safety failure detectors for a protocol solving the problem of global data computation.