Copyright © 2005 The Institute of Electronics, Information and Communication Engineers
IEICE/IEEE Joint Special Section on Autonomous Decentralized Systems -- Papers |
Behavioral Analysis of a Fault-Tolerant Software System with Rejuvenation
1 The authors are with the Department of Information Engineering, Graduate School of Engineering, Hiroshima University, Higashi-hiroshima-shi, 7398527 Japan. E-mail: rinsaka{at}rel.hiroshima-u.ac.jp
In recent years, considerable attention has been devoted to continuously running software systems whose performance characteristics are smoothly degrading in time. Software aging often affects the performance of a software system and eventually causes it to fail. A novel approach to handle transient software failures due to software aging is called software rejuvenation, which can be regarded as a preventive and proactive solution that is particularly useful for counteracting the aging phenomenon. In this paper, we focus on a high assurance software system with fault-tolerance and preventive rejuvenation, and analyze the stochastic behavior of such a highly critical software system. More precisely, we consider a fault-tolerant software system with two-version redundant structure and random rejuvenation schedule, and evaluate quantitatively some dependability measures like the steady-state system availability and MTTF based on the familiar Markovian analysis. In numerical examples, we examine the dependence of two fault tolerant techniques; design and environment diversity techniques, on the system dependability measures.
Key Words: software fault tolerance, rejuvenation, software aging, bivariate failure mode, continuous-time Markov chain
Manuscript received March 28, 2005. Manuscript revised June 28, 2005.