Title | Optimal software rejuvenation for tolerating soft failures |
Publication Type | Journal Article |
Year of Publication | 1996 |
Authors | A Pfening, S Garg, A Puliafito, M Telek, and KS Trivedi |
Journal | Performance Evaluation |
Volume | 27-28 |
Start Page | 491 |
Pagination | 491 - 506 |
Date Published | 01/1996 |
Abstract | In recent studies, the phenomenon of software "aging" has come to light which causes performance of a software to degrade with time. Software rejuvenation is a fault tolerance technique which counteracts aging. In this paper, we address the problem of determining the optimal time to rejuvenate a server type software which experiences "soft failures" (witnessed in telecommunication systems) because of aging. The service rate of the software gradually decreases with time and settles to a very low value. Since the performability in this state is unacceptable, it is necessary to "renew" the software to its peak performance level. We develop Markov decision models for such a system for two different queuing policies. For each policy, we define the look-ahead-n cost functions and prove results on the convergence of these functions to the optimal minimal cost function. We also prove simple rules to determine optimal times to rejuvenate for a realistic cost criterion. Finally, the results are illustrated numerically and the effectiveness of the MDP model is compared with that of the simple rules. |
DOI | 10.1016/s0166-5316(96)90042-5 |
Short Title | Performance Evaluation |