Availability Analysis of Application Servers Using Software Rejuvenation and Virtualization

Abstract

Demands on software reliability and availability have increased tremendously due to the nature of present day applications. We focus on the aspect of software for the high availability of application servers since the unavailability of servers more often originates from software faults rather than hardware faults. The software rejuvenation technique has been widely used to avoid the occurrence of unplanned failures, mainly due to the phenomena of software aging or caused by transient failures. In this paper, first we present a new way of using the virtual machine based software rejuvenation named VMSR to offer high availability for application server systems. Second we model a single physical server which is used to host multiple virtual machines (VMs) with the VMSR framework using stochastic modeling and evaluate it through both numerical analysis and SHARPE (Symbolic Hierarchical Automated Reliability and Performance Evaluator) tool simulation. This VMSR model is very general and can capture application server characteristics, failure behavior, and performability measures. Our results demonstrate that VMSR approach is a practical way to ensure uninterrupted availability and to optimize performance for aging applications.

A survey on virtual machine migration and server consolidation frameworks for cloud data centers

“…VM migration practice exploits live or non-live patterns to move a complete virtual server across physical machines to successfully attain load balancing (Shiraz et al, 2013b, Yao et al, 2014, power efficiency (Dong et al, 2013;Mishra et al, 2012;Shrivastava et al, 2011), fault tolerance (Nagarajan et al, 2007, NGUYEN et al, 2013Thein and Park, 2009), and system maintenance (Asberg et al, 2011;Liu et al, 2011;Wu et al, 2013;Zhou et al, 2013) within a DC. A live VM migration pattern guarantees continuous service provisioning to the hosted applications during the VM memory transfer process (Kapil et al, 2013;Shribman and Hudzia, 2013), whereas non-live VM migration (Kozuch and Satyanarayanan, 2002;Wang et al, 2010a) suspends application execution prior to memory image transfer (Aikema et al, 2012;Glazer and Tropper, 1993;Satyanarayanan, 2002, Kozuch et al, 2002;Milojičić et al, 2000).…”

Availability Modelling of Fault Tolerant Cloud Computing System

“…By evaluating the collected fault conditions and operating system resources degradation, this strategy actively anticipates sudden framework blackouts [22]. Dissimilar to downtime brought on by unexpected let-down events, the lost time identified with software renewal can be planned at the attention of the client/manager.…”

Virtual networks dependability assessment framework

“…A technique for computing a dependability metric in virtual computing system based on stochastic Petri net models is discussed in Hu et al (2010). A CTMC-based model for evaluating dependability metrics is discussed in Zhang et al (2009) and Thein and Park (2009). In Hong et al (2012), CTMC is used for analysing the availability of a cluster system with multiple nodes.…”