The Timely Computing Base
Paulo Verı́ssimo, António Casimiro · 1999
A large number of the emerging services have interactivity or mission-criticality requirements, which are best translated into requirements for fault-tolerance and real-time. To implement these services a given distributed systems model must be chosen. However, we have to face the following problem: fully asynchronous models do not satisfy our needs, because they do not allow timeliness specifications; on the other hand, correct operation under fully synchronous models is very difficult to achieve (if at all possible) in large-scale infrastructures, since they have poor baseline timeliness properties. Then, what system model to use for applications with synchrony (i.e. real-time) requirements running on environments with uncertain timeliness? We propose a framework that describes the problem in a generic way. We call it the Timely Computing Base (TCB) model. A detailed description of the TCB model can be found in [4].