Availability analysis of a scalable intrusion tolerant architecture with two detection modes

Abstract

In this paper we consider a discrete-time availability model of an intrusion tolerant system with two detection modes; automatic detection mode and manual detection mode. The stochastic behavior of the system is formulated by a discrete-time semi-Markov process and analyzed through an embedded Markov chain (EMC) approach. We derive the optimal switching time from an automatic detection mode to a manual detection mode, which maximizes the steady-state system availability. Numerical examples are presented for illustrating the optimal switching of detection mode and its availability performance. availability, detection mode, EMC approach, Cloud computing environment. © 2009 Springer-Verlag.