Availability Analysis of Software Systems with Rejuvenation and Checkpointing

Mathematics

Junjun Zheng¹  Hiroyuki Okamura²  Tadashi Dohi² 

[1] Department of Information Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu 5258577, Japan;Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 7398527, Japan;

关键词: software rejuvenation;    checkpointing;    optimal rejuvenation-trigger timing;    steady-state system availability;    phase expansion;    human-error factors;   

DOI  :  10.3390/math9080846

来源: DOAJ

【 摘 要 】

In software reliability engineering, software-rejuvenation and -checkpointing techniques are widely used for enhancing system reliability and strengthening data protection. In this paper, a stochastic framework composed of a composite stochastic Petri reward net and its resulting non-Markovian availability model is presented to capture the dynamic behavior of an operational software system in which time-based software rejuvenation and checkpointing are both aperiodically conducted. In particular, apart from the software-aging problem that may cause the system to fail, human-error factors (i.e., a system operator’s misoperations) during checkpointing are also considered. To solve the stationary solution of the non-Markovian availability model, which is derived on the basis of the reachability graph of stochastic Petri reward nets and is actually not one of the trivial stochastic models such as the semi-Markov process and the Markov regenerative process, the phase-expansion approach is considered. In numerical experiments, we illustrate steady-state system availability and find optimal software-rejuvenation policies that maximize steady-state system availability. The effects of human-error factors on both steady-state system availability and the optimal software-rejuvenation trigger timing are also evaluated. Numerical results showed that human errors during checkpointing both decreased system availability and brought a significant effect on the optimal rejuvenation-trigger timing, so that it should not be overlooked during system modeling.

【 授权许可】

Unknown