Sharif Digital Repository

Proposing a comprehensive architecture for cloud federation with the aim of satisfying stakeholders the most, is one of the most challenging issues in this context. For an architecture to be comprehensive, requirements should be elicited thoroughly in early stages of architecture design. Since covering all requirements is a very complicated task, prioritization is considered to be a vital step which can help architects to focus on more important requirements in their design as well as to evaluate existing architectures. In this research, architecturally signifcant quality requirements of cloud federation for aggregated cloud architectures are studied and categorized. Moreover, elicited... 

With the growing use of computer systems, especially in form of web applications, software development and customer requirements has become more complex. Modern computer systems are supposed to achieve non-functional requirements in addition to functional requirements. Non-functional requirements are also called software quality attributes. One of the most important quality attributes for today's software systems is performance. Today’s softwares due to the growing number of their users, need more efficiency than ever to properly meet the performance request.Storage components and databases are the most important factors in causing performance bottlenecks in web applications. Most of... 

Given the importance of software architecture in the field of software engineering and its influence, much attention has been paid to it in the past few decades. This has led to significant progress in the development and expansion of the technical foundations of design as an engineered discipline and today is regarded as a mature branch of producing cycle and software development. But considerations related to design based on architecture and activities required to achieve a correct and complete architecture 100 percent is difficult and considering progress of technology, this problem is adding to the concerns in the field of architecture. As a result, different approaches and activities... 

In cloud federation, a number of cloud service providers (CSP) interoperate to rent each other's computing resources. When a CSP finds a lack in its resources, it can use other CSPs' spare resources for its jobs. This way, the number of physical resources needed by CSPs decreases, since they don't need a pessimistic forecast for resource provision. In this thesis, we analyze possibility of such federation from an architectural viewpoint and then, propose a model to realize such federation. First, we study architectural requirements of cloud federation. A number of important requirements are gathered from previous work. These requirements are then categorized and prioritized, showing that... 

With long-term evolution of large scale software systems, the study and engineering of architectural evolution becomes more and more important. In order to manage high level changes, the architects should plan the architecture evolution in a series of releases. Planning and analysis of architectural evolution is a challenge and plays a significant role in evolution management. An assessment solution could promote overall accuracy and quality of the evolution process. Compliance checking with expert-defined rules is a well-known assessment solution and could be applied in the field of architectural evolution. In this thesis, a solution is proposed in order to compliance check these evolution... 

One of the major and costly activity in Information Systems is controlling the quality of Service-Oriented Architecture (SOA) that has some challenges such as a long time is needed for detection and refinement of changeability of architecture qualities, how to quantify its quality attributes and variation in architecture changes. Self-adaptation of architecture is a novel automatic method that can be composed with architectural patterns to quantify and control the quality of SOA. In this paper, a self-adaptive framework, process and methodology is defined for this issue. Based on MAPE-K model, evaluation metrics by applying architectural tactics and final quality based on quality models and... 

Cloud computing offers its customers and organizations many advantages such as turning CAPEX to OPEX in the business side, and enabling scalability and fast and easy resource provisioning in the technical side. Using these features, companies can benefit from deployment in the cloud at a lower cost, and at the same time, focus more on their business. Therefore, many organizations are migrating their vital systems to the cloud because of its many benefits. Research on this topic has been started a few years ago, and since then, many approaches including architecture-based, model-driven, and SOA-based approaches have been proposed. Some of these solutions are just adaptations of the... 

Nowadays, due to the enlargement and complexity of software systems, traditional approaches to software development are not as efficient as before, hence there is a need for new approaches in design, implementation, and maintenance of software systems and processes. Complexity and enlargement of design and initial implementation of systems and processes on one hand, and the requirements appear in the maintenance phase on the other hand, makes the dynamic design of systems and processes a very important issue. However, adding dynamism and changeability to the systems has an upper bound, and additionally, it is impossible to definitely predict trend of systems and processes in the future. This...