Bøger af Yun Yang

Cloud computing is the latest market-oriented computing paradigm which brings software design and development into a new era characterized by ¿XaaS¿, i.e. everything as a service. Cloud workflows, as typical software applications in the cloud, are composed of a set of partially ordered cloud software services to achieve specific goals. However, due to the low QoS (quality of service) nature of the cloud environment, the design of workflow systems in the cloud becomes a challenging issue for the delivery of high quality cloud workflow applications. To address such an issue, this book presents a systematic investigation to the three critical aspects for the design of a cloud workflow system, viz. system architecture, system functionality and quality of service. Specifically, the system architecture for a cloud workflow system is designed based on the general four-layer cloud architecture, viz. application layer, platform layer, unified resources layer and fabric layer. The system functionality for a cloud workflow system is designed based on the general workflow reference model but with significant extensions to accommodate software services in the cloud. The support of QoS is critical for the quality of cloud workflow applications. This book presents a generic framework to facilitate a unified design and development process for software components that deliver lifecycle support for different QoS requirements. While the general QoS requirements for cloud workflow applications can have many dimensions, this book mainly focuses on three of the most important ones, viz. performance, reliability and security. In this book, the architecture, functionality and QoS management of our SwinDeW-C prototype cloud workflow system are demonstrated in detail as a case study to evaluate our generic design for cloud workflow systems. To conclude, this book offers a general overview of cloud workflow systems and provides comprehensive introductions to the design of thesystem architecture, system functionality and QoS management.

The major contributions of this book are that we have provided a set of new concepts, innovative methods and algorithms for temporal verification in grid workflow systems. With these, we can significantly improve overall temporal verification effectiveness and efficiency. This would eventually improve the overall performance and usability of grid workflow systems because temporal verification can be viewed as a service or function of grid workflow systems. Consequently, by deploying the new concepts, innovative methods and algorithms, grid workflow systems would be able to better support large-scale sophisticated scientific and business processes in complex e-science and e-business applications in the context of grid economy.