Authors: Hirokazu Ozaki
Addresses: Department of Systems and Informatics, Hokkaido Information University, 59-2, Nishi-Nopporo, Ebetsu, Hokkaido 069 8585, Japan
Abstract: In this study, we investigate the user-perceived availability of M-for-N shared spare-server systems. We assume that there are N identical working servers, each serving a single user group, and M identical shared spare servers in the system. We also assume that the time to failure of the server is subject to an exponential distribution, and the time needed to repair a failed server is subject to the Erlang type-k distributions. Under these assumptions, our numerical computation shows that there exists an optimal size (M + N) for shared spare-server systems with respect to the availability and cost for a given condition.
Keywords: cloud computing; user-perceived reliability; shared protection systems; probability distribution; availability; optimal configuration; spare-server.
International Journal of Information and Communication Technology, 2019 Vol.14 No.2, pp.218 - 235
Received: 25 Apr 2016
Accepted: 26 Mar 2017
Published online: 17 Jan 2019 *