Reliability analysis of data center networks based on precise and imprecise diagnosis strategies

Fault tolerance and reliability are the crucial issues for data center networks (DCNs). Both the g-extra conditional diagnosis (g-ECD) precise strategy and the t/k-diagnosis imprecise strategy play essential role in the reliability of networks. For the data center network based on DCell structure D-m,D-n. we prove that: 1) the g-ECD of D-m,D-n under the MM* model is (g + 1)m n - 1 with n >= 4, m >= 3, and 1 <= g <= min {n/4, m - 2}: 2) D-m,D-n is [(k + 1)(m - 1) +n]/k-diagnosable under the MM* model with n >= 2, m >= 2, and 0 <= k <= n-1. Furthermore, for N-server DCN, we propose the first t/k-diagnosis algorithm on D-m,D-n under the MM* model, namely t/k-D-m,D-n-DIAG with O (NlogN) time complexity. Comparing with the traditional t-diagnosable algorithm by Ziwich and Duarte (2016) [11], on D-m,D-n, the t/k-D-m,D-n -DIAG can identify the number of faulty vertices is almost k times larger than the t-diagnosable algorithm, where the time complexity of t-diagnosable algorithm is about O (N(logN)(3)). These results provide a quantitative analysis for the reliability and availability evaluation of a large-scale DCN. (C) 2019 Elsevier B.V. All rights reserved.