Cloud Architecture Evaluation

Cloud computing has introduced numerous ways to build software systems in the cloud environment. The complexity of today’s system architectures require architecture evaluation in the designing phase of the system, in the implementation phase, and in the maintenance phase. There are many different architecture evaluation models. This thesis discusses three different evaluation models: architecture tradeoff analysis method, cost-benefit analysis method, and AWS Well-Architected framework. The AWS Well-Architected framework is deeply evaluated by performing an architectural evaluation for the case study software: Lixani 5. This thesis introduces and compares the opportunities for cloud architecture evaluation by literature review, case study, and interviews with experts. The thesis begins with introduction to cloud computing, cloud architecture models and architecture evaluation methods. An architecture evaluation for a case study software is then carried out. This thesis also contains interviews with experts, producing knowledge on how the system architecture is being evaluated in the field. The research methods used in the thesis are literature review, case study, and expert interviews. This thesis attempts to describe and assess the architecture evaluation models by using the research methods. In addition, this thesis introduces and discusses the case study software – Lixani 5 – and its architectural decisions. Based on research in the thesis it was noted that all three studied software architecture evaluation models are suitable options for reviewing software architecture. All models included positive and negative aspects and none of them was seen as superior compared to the others. Based on the interviews with experts it was noted that there are also multiple other efficient ways to evaluate the system architecture than the models discussed in the thesis. These ways included a technology audit template and a proof-of-concept culture

The Capability and Support of Structure Capital on BIM Innovation in SME

The Architecture, Engineering, and Construction (AEC) industry has been changing over the years with the emergence of BIM. The small and medium sized enterprises are not left out of the change, bringing distortion to their business environment and process. Extant studies have revealed that Structure Capital (SC) is an integral part of the innovative capacity of firms, this study examines the capability of SC on Architectural SME firms in Nigeria. The research was designed in three stages, empirical enquiry, analysis, and synthesis. The empirical enquiry comprised of theory formulation and fieldwork data collection. The theory formulation was achieved by proposing an evaluation framework using a systematic literature review on three SC components; system structure, infrastructure and facilities, and process and scheme. The evaluation framework constituted a set of independent variables comprising thirteen indicators categorised under these three components. The evaluation framework was used to collect data from the fieldwork. It involved a questionnaire survey and case study interviews with a sample of SME architectural firms in Nigeria. The survey involved administering questionnaires to 334 firms which yielded 217 completed questionnaires. Six case study interviews were also conducted within the same period.  The survey data enabled the evaluation of the framework using a multiple regression analysis. To examine the relationship between these components and the BIM Business Value Capital (BBVC), a multiple linear regression and correlation analysis was conducted to assess whether the independent variables predict the dependent variable. The result indicated that all the three components of the SC have a significant correlation with BBVC. However, some indicators were not found to be useful in predicting BBVC, which include: flexible administrative systems and knowledge management system structures. In comparison, the availability of specific office infrastructures for BIM and the availability of in-house training were found to be useful. The research concluded that the development of the SC of SME firms in the AEC industry is essential for the business process of BIM adoption. Keywords: BIM, Structure Capital (SC), SME, Architect, BBVC. DOI: 10.7176/IKM/9-2-0

Integrating IRT analysis into LMS for item pool optimization

Due to the computerization of assessment tests, the use of Item Response Theory (IRT) has become commonplace for educational assessment development, evaluation, and refinement. When used appropriately by a Learning Management System (LMS), IRT can improve the assessment quality, increase the efficiency of the testing process, and provide in-depth descriptions of item and test properties. This paper introduces a methodological and architectural framework which embeds an IRT analysis tool in an LMS so as to extend its functionality with assessment optimization support. By applying a set of validity rules to the statistical indices produced by the IRT analysis, the enhanced LMS is able to detect several defective items from an item pool which are then reported for reviewing of their content. Assessment refinement is achieved by repeatedly employing this process until all flawed items are eliminated

Tailoring the Cyber Security Framework: How to Overcome the Complexities of Secure Live Virtual Machine Migration in Cloud Computing

This paper proposes a novel secure live virtual machine migration framework by using a virtual trusted platform module instance to improve the integrity of the migration process from one virtual machine to another on the same platform. The proposed framework, called Kororā, is designed and developed on a public infrastructure-as-a-service cloud-computing environment and runs concurrently on the same hardware components (Input/Output, Central Processing Unit, Memory) and the same hypervisor (Xen); however, a combination of parameters needs to be evaluated before implementing Kororā. The implementation of Kororā is not practically feasible in traditional distributed computing environments. It requires fixed resources with high-performance capabilities, connected through a high-speed, reliable network. The following research objectives were determined to identify the integrity features of live virtual machine migration in the cloud system: To understand the security issues associated with cloud computing, virtual trusted platform modules, virtualization, live virtual machine migration, and hypervisors; To identify the requirements for the proposed framework, including those related to live VM migration among different hypervisors; To design and validate the model, processes, and architectural features of the proposed framework; To propose and implement an end-to-end security architectural blueprint for cloud environments, providing an integrated view of protection mechanisms, and then to validate the proposed framework to improve the integrity of live VM migration. This is followed by a comprehensive review of the evaluation system architecture and the proposed framework state machine. The overarching aim of this paper, therefore, is to present a detailed analysis of the cloud computing security problem, from the perspective of cloud architectures and the cloud service delivery models. Based on this analysis, this study derives a detailed specification of the cloud live virtual machine migration integrity problem and key features that should be covered by the proposed framewor

Optimizing energy-efficiency for multi-core packet processing systems in a compiler framework

Network applications become increasingly computation-intensive and the amount of traffic soars unprecedentedly nowadays. Multi-core and multi-threaded techniques are thus widely employed in packet processing system to meet the changing requirement. However, the processing power cannot be fully utilized without a suitable programming environment. The compilation procedure is decisive for the quality of the code. It can largely determine the overall system performance in terms of packet throughput, individual packet latency, core utilization and energy efficiency. The thesis investigated compilation issues in networking domain first, particularly on energy consumption. And as a cornerstone for any compiler optimizations, a code analysis module for collecting program dependency is presented and incorporated into a compiler framework. With that dependency information, a strategy based on graph bi-partitioning and mapping is proposed to search for an optimal configuration in a parallel-pipeline fashion. The energy-aware extension is specifically effective in enhancing the energy-efficiency of the whole system. Finally, a generic evaluation framework for simulating the performance and energy consumption of a packet processing system is given. It accepts flexible architectural configuration and is capable of performingarbitrary code mapping. The simulation time is extremely short compared to full-fledged simulators. A set of our optimization results is gathered using the framework

Adaptation-Aware Architecture Modeling and Analysis of Energy Efficiency for Software Systems

This thesis presents an approach for the design time analysis of energy efficiency for static and self-adaptive software systems. The quality characteristics of a software system, such as performance and operating costs, strongly depend upon its architecture. Software architecture is a high-level view on software artifacts that reflects essential quality characteristics of a system under design. Design decisions made on an architectural level have a decisive impact on the quality of a system. Revising architectural design decisions late into development requires significant effort. Architectural analyses allow software architects to reason about the impact of design decisions on quality, based on an architectural description of the system. An essential quality goal is the reduction of cost while maintaining other quality goals. Power consumption accounts for a significant part of the Total Cost of Ownership (TCO) of data centers. In 2010, data centers contributed 1.3% of the world-wide power consumption. However, reasoning on the energy efficiency of software systems is excluded from the systematic analysis of software architectures at design time. Energy efficiency can only be evaluated once the system is deployed and operational. One approach to reduce power consumption or cost is the introduction of self-adaptivity to a software system. Self-adaptive software systems execute adaptations to provision costly resources dependent on user load. The execution of reconfigurations can increase energy efficiency and reduce cost. If performed improperly, however, the additional resources required to execute a reconfiguration may exceed their positive effect. Existing architecture-level energy analysis approaches offer limited accuracy or only consider a limited set of system features, e.g., the used communication style. Predictive approaches from the embedded systems and Cloud Computing domain operate on an abstraction that is not suited for architectural analysis. The execution of adaptations can consume additional resources. The additional consumption can reduce performance and energy efficiency. Design time quality analyses for self-adaptive software systems ignore this transient effect of adaptations. This thesis makes the following contributions to enable the systematic consideration of energy efficiency in the architectural design of self-adaptive software systems: First, it presents a modeling language that captures power consumption characteristics on an architectural abstraction level. Second, it introduces an energy efficiency analysis approach that uses instances of our power consumption modeling language in combination with existing performance analyses for architecture models. The developed analysis supports reasoning on energy efficiency for static and self-adaptive software systems. Third, to ease the specification of power consumption characteristics, we provide a method for extracting power models for server environments. The method encompasses an automated profiling of servers based on a set of restrictions defined by the user. A model training framework extracts a set of power models specified in our modeling language from the resulting profile. The method ranks the trained power models based on their predicted accuracy. Lastly, this thesis introduces a systematic modeling and analysis approach for considering transient effects in design time quality analyses. The approach explicitly models inter-dependencies between reconfigurations, performance and power consumption. We provide a formalization of the execution semantics of the model. Additionally, we discuss how our approach can be integrated with existing quality analyses of self-adaptive software systems. We validated the accuracy, applicability, and appropriateness of our approach in a variety of case studies. The first two case studies investigated the accuracy and appropriateness of our modeling and analysis approach. The first study evaluated the impact of design decisions on the energy efficiency of a media hosting application. The energy consumption predictions achieved an absolute error lower than 5.5% across different user loads. Our approach predicted the relative impact of the design decision on energy efficiency with an error of less than 18.94%. The second case study used two variants of the Spring-based community case study system PetClinic. The case study complements the accuracy and appropriateness evaluation of our modeling and analysis approach. We were able to predict the energy consumption of both variants with an absolute error of no more than 2.38%. In contrast to the first case study, we derived all models automatically, using our power model extraction framework, as well as an extraction framework for performance models. The third case study applied our model-based prediction to evaluate the effect of different self-adaptation algorithms on energy efficiency. It involved scientific workloads executed in a virtualized environment. Our approach predicted the energy consumption with an error below 7.1%, even though we used coarse grained measurement data of low accuracy to train the input models. The fourth case study evaluated the appropriateness and accuracy of the automated model extraction method using a set of Big Data and enterprise workloads. Our method produced power models with prediction errors below 5.9%. A secondary study evaluated the accuracy of extracted power models for different Virtual Machine (VM) migration scenarios. The results of the fifth case study showed that our approach for modeling transient effects improved the prediction accuracy for a horizontally scaling application. Leveraging the improved accuracy, we were able to identify design deficiencies of the application that otherwise would have remained unnoticed

Quality-aware model-driven service engineering

Service engineering and service-oriented architecture as an integration and platform technology is a recent approach to software systems integration. Quality aspects ranging from interoperability to maintainability to performance are of central importance for the integration of heterogeneous, distributed service-based systems. Architecture models can substantially influence quality attributes of the implemented software systems. Besides the benefits of explicit architectures on maintainability and reuse, architectural constraints such as styles, reference architectures and architectural patterns can influence observable software properties such as performance. Empirical performance evaluation is a process of measuring and evaluating the performance of implemented software. We present an approach for addressing the quality of services and service-based systems at the model-level in the context of model-driven service engineering. The focus on architecture-level models is a consequence of the black-box character of services

Evaluation of the architectural features and physical environment in early childhood education framework

Many initial childhood settings worldwide have started to create an environment and educational system that would increase the children’s environmental awareness and the ways to minimize it. A newly built ecological kindergarten in Antalya, Turkey, has adopted an educational system in which children are getting involved with nature in most of their daily routines. This study intended to learn if the physical environment of the declared setting responds to the early childhood environmental education work frame. Accordingly, the study has adopted “Guidelines for Excellence, Early Childhood Environmental Education Programs’’ as the primary resource for an evaluation checklist. Data collection is conducted via an in-depth site analysis, as well as the questionnaire survey of teachers and parents regarding their perception of the kindergarten’s physical environment. The results showed that the physical environment of the kindergarten does not meet the requirements of the early education environmental framework. This study underlines the importance of profound research studies that analyze the architectural features of an early environmental education setting and the ways improving its physical attributes may promote the children environmental education.No sponso

Planning strategically, designing architecturally : a framework for digital library services

In an era of unprecedented technological innovation and evolving user expectations and information seeking behaviour, we are arguably now an online society, with digital services increasingly common and increasingly preferred. As a trusted information provider, libraries are in an advantageous position to respond, but this requires integrated strategic and enterprise architecture planning, for information technology (IT) has evolved from a support role to a strategic role, providing the core management systems, communication networks, and delivery channels of the modern library. Further, IT components do not function in isolation from one another, but are interdependent elements of distributed and multidimensional systems encompassing people, processes, and technologies, which must consider social, economic, legal, organisational, and ergonomic requirements and relationships, as well as being logically sound from a technical perspective. Strategic planning provides direction, while enterprise architecture strategically aligns and holistically integrates business and information system architectures. While challenging, such integrated planning should be regarded as an opportunity for the library to evolve as an enterprise in the digital age, or at minimum, to simply keep pace with societal change and alternative service providers. Without strategy, a library risks being directed by outside forces with independent motivations and inadequate understanding of its broader societal role. Without enterprise architecture, it risks technological disparity, redundancy, and obsolescence. Adopting an interdisciplinary approach, this conceptual paper provides an integrated framework for strategic and architectural planning of digital library services. The concept of the library as an enterprise is also introduced

Framework for software architecture visualization assessment.

In order to assess software architecture visualisation strategies, we qualitatively characterize then construct an assessment framework with 7 key areas and 31 features. The framework is used for evaluation and comparison of various strategies from multiple stakeholder perspectives. Six existing software architecture visualisation tools and a seventh research tool were evaluated. All tools exhibited shortcomings when evaluated in the framework