Computer systems availability evaluation using a segregated failures model |
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| Authors: | Sergiy A Vilkomir David L Parnas Veena B Mendiratta Eamonn Murphy |
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| Affiliation: | 1. Software Quality Research Laboratory (SQRL), Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, U.S.A.;2. Software Quality Research Laboratory (SQRL), Department of Computer Science and Information Systems, University of Limerick, Limerick, Ireland;3. Chief Technology Office, Alcatel‐Lucent, Naperville, IL, U.S.A.;4. Department of Mathematics and Statistics, University of Limerick, Limerick, Ireland |
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| Abstract: | This paper presents the segregated failures model (SFM) of availability of fault‐tolerant computer systems with several recovery procedures. This model is compared with a Markov chain model and its advantages are explained. The basic model is then extended for the situation when the coverage factor is unknown and the failure escalation rates must be used instead. A simple practical analytical approach to availability evaluation is provided and illustrated in detail by estimating the availability of two versions of a reliable clustered computing architecture. For these examples, numeric values of availability indexes are computed and the contribution of each recovery procedure to total system availability is analysed. Copyright © 2008 John Wiley & Sons, Ltd. |
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| Keywords: | software fault tolerance availability reliability recovery fault model |
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