1,721,063 research outputs found
A survey on software aging and rejuvenation in the cloud
No full textThe adoption of cloud computing for providing resource and delivering services is an irreversible trend. For most IT companies, the quality of provided services is strongly dependent on reliability and performance of the underlying cloud technologies. A widely studied problem that can greatly affect the user experience is runtime software aging, whose main countermeasure is a proactive maintenance action known as rejuvenation. This article reviews the effort conducted so far by the software aging and rejuvenation (SAR) community in the cloud domain. A set of 105 papers has been examined from three source digital libraries in order to have a clear view of the state of the art. The paper characterizes the cloud-related SAR literature according to four dimensions: the publication trends, the aging analysis methods and metrics, the rejuvenation solutions, the validation approach. Results witness an increasing interest in this area (with 58% of the studies published in the last 5 years), an equivalent role of measurement-based and model-based solutions for aging analysis (42 and 40 studies, respectively) and a prevalent interest for rejuvenation (76/105 of the studies deals with rejuvenation)
On adaptive sampling-based testing for software reliability assessment
No full textAssessing reliability of software programs during validation is a challenging task for engineers. The assessment is not only required to be unbiased, but it needs to provide tight variance (hence, tight confidence interval) with as few test cases as possible. Statistical sampling is a theoretically sound approach for reliability testing, but it is often impractical in its current form, because of too many test cases required to achieve desired confidence levels, especially when the software has few residual faults inside.
We claim that the potential of statistical sampling methods is largely underestimated. This paper presents an adaptive sampling-based testing (AST) strategy for reliability assessment. A two-stage conceptual framework is defined, where adaptiveness is included to uncover residual faults earlier, while various sampling-based techniques are proposed to improve the efficiency (in terms of variance-test cases tradeoff) by better exploiting the information available to tester. An empirical study is conducted to assess the AST performance and compare the proposed sampling techniques to each other on real programs
Testing techniques selection based on ODC fault types and software metrics
No full textSoftware testing techniques differ in the type of faults they are more prone to detect, and their performance varies depending on the features of the application being tested. Practitioners often use informally their knowledge about the software under test in order to combine testing techniques for maximizing the number of detected faults.
This work presents an approach to enable practitioners to select testing techniques according to the features of the software to test. A method to build a testing-related base of knowledge for tailoring the techniques selection process to the specific application(s) is proposed. The method grounds upon two basic steps: i) constructing, on an empirical basis, models to characterize the software to test in terms of fault types it is more prone to contain; ii) characterizing testing techniques with respect to fault types they are more prone to detect in the given context.
Using the created base of knowledge, engineers within an organization can define the mix of techniques so as to maximize the effectiveness of the testing process for their specific software
Online Reliability Monitoring: a Hybrid Approach
No full textAssuring high reliability levels in complex software systems is difficult. The spread of component-based paradigm brought, along with many advantages, new thorny problems and challenges. Various approaches have been proposed to guarantee high reliability and cope with such problems – among these, proactive policies are particularly effective and inexpensive. The ability to monitor the system at runtime and to give online estimations about the trend of dependability attribute of interest, is the key to implement strategies aiming at forecasting, and thus proactively preventing, the system failure occurrence. In this paper, an online reliability monitoring approach is proposed. It combines benefits of architecture- based reliability model and dynamic analysis, so as to integrate static modeling power with representative operational data. Its usage is illustrated by a prototype implementation, a case-study and preliminary results
RELAI testing: a technique to assess and improve software reliability
No full textTesting software for assessing or improving reliability presents several practical challenges. Conventional operational testing is a fundamental strategy that simulates the real usage of the system in order to expose failures with the highest occurrence probability. However, practitioners find it unsuitable for assessing/delivering high reliability levels, and they do not see the adoption of a “real” usage profile estimate as a sensible idea, being it a source of non-quantifiable uncertainty. Debug testing techniques aim to expose as many failures as possible, but regardless of their impact on runtime reliability. These strategies are used either to assess or to improve reliability, but cannot improve and assess reliability in the same testing session. This article proposes Reliability Assessment and Improvement (RELAI) testing, a new technique thought to improve the delivered reliability, by an adaptive testing scheme, while providing, at the same time, a continuous assessment of reliability attained through testing and fault removal. The technique also quantifies the impact of a partial knowledge of the operational profile. RELAI is positively evaluated on four software applications compared, in separate experiments, with techniques conceived either for reliability improvement or for reliability assessment, demonstrating substantial improvements in both cases
Testing the Resilience of MEC-based IoT Applications Against Resource Exhaustion Attacks
Full text linkHybrid Simulation and Test of Vessel Traffic Systems on the Cloud
Full text linkThis paper presents a cloud-based hybrid simulation platform to test large-scale distributed System-of-Systems (SoS) for the management and control of maritime traffic, the so-called Vessel Traffic Systems (VTS). A VTS consists of multiple, heterogeneous, distributed and interoperating systems, including radar, automatic identification systems, direction finders, electro-optical sensors, gateways to external VTSs, information systems; identifying, representing and analyzing interactions is a challenge to the evaluation of the real risks for safety and security of the marine environment. The need for reproducing in fabric the system behaviors that could occur in situ demands for the ability of integrating emulated and simulated environments to cope with the different testability requirements of involved systems and to keep testing cost sustainable. The platform exploits hybrid simulation and virtualization technologies, and it is deployable on a private cloud, reducing the cost of setting up realistic and effective testing scenarios
Defect analysis in mission-critical software systems: a detailed investigation
No full textThe practice of defect analysis is recognized as an essential task for software process measurement, yet its
effective application in the industrial development of large-scale software systems raises several challenges.
We report the results of a study conducted at SELEX ES - a large system integrator leader in the market of
software-intensive mission-critical systems. The article describes the defect analysis approach that we tailored to evaluate the software development process with respect to the quality of produced software and
its relation with the required effort. Three key phases of the process were addressed, regarding the software
implementation, the testing phase and the prerelease defect fixing activity, over a set of six computer software configuration items developed from 2009 to 2012 for the naval and maritime domain product line.
The analysis highlighted efficiency bottlenecks in each of the monitored phases, providing company engineers with insights about room for process improvement. The implemented approach, the observed phenomena and the inferred conclusions are of support to practitioners coping with systems, development models and
industrial environments similar to the considered one
Dynamic test planning: a study in an industrial context
No full textTesting accounts for a relevant part of the production cost of complex or critical software systems. Nevertheless, time and resources budgeted to testing are often underestimated with respect to the target quality goals. Test managers need engineering methods to perform appropriate choices in spending testing resources, so as to maximize the outcome. We present a method to dynamically allocate testing resources to software components minimizing the estimated number of residual defects and/or the estimated residual defect density. We discuss the application to a real-world critical system in the homeland security domain. We describe a support tool aimed at easing industrial technology transfer by hiding to practitioners the mathematical details of the method application
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