Generic timing fault tolerance using a timely computing base

Abstract

Designing applications with timeliness requirements in environments of uncertain synchrony is known to be a difficult problem. In this paper we follow the perspective of timing fault tolerance: tinting errors occur and they are processed using redundancy, e.g., component replication, to recover and deliver timely service. We introduce a paradigm for generic tinting fault tolerance with replicated state machines. The paradigm is based on the existence of Timing Failure Detection with tinted completeness and accuracy properties. Generic timing fault tolerance implies the ability to dependably observe the system and to timely notify timing failures, which we discuss in the paper On the other hand, it ensures replica determinism with respect to time (temporal consistency), and safety in case of spare exhaustion. We show that the paradigm can be addressed and realized in the framework of the timely computing base (TCB) model and architecture. Furthermore, we illustrate the generality, of our approach by reviewing previous existing solutions and by showing that in contrast with ours, they, only secure a restricted semantics, or simply provide ad-hoc solutions.