Xiao Liu PhD Thesis.pdf - Faculty of Information and Communication ...
Xiao Liu PhD Thesis.pdf - Faculty of Information and Communication ...
Xiao Liu PhD Thesis.pdf - Faculty of Information and Communication ...
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Chapter 1<br />
Introduction<br />
This thesis proposes a novel probabilistic temporal framework to address the<br />
limitations <strong>of</strong> conventional temporal research <strong>and</strong> the new challenges for lifecycle<br />
support <strong>of</strong> time-constrained e-science applications in cloud workflow systems. The<br />
novel research reported in this thesis is concerned with the investigation <strong>of</strong> how to<br />
deliver high temporal QoS (Quality <strong>of</strong> Service) from the perspective <strong>of</strong> cost<br />
effectiveness, especially at workflow runtime. A set <strong>of</strong> new concepts, innovative<br />
strategies <strong>and</strong> algorithms are designed <strong>and</strong> developed to support temporal QoS over<br />
the whole lifecycles <strong>of</strong> scientific cloud workflow applications. Case study,<br />
comparisons, quantitative evaluations <strong>and</strong>/or theoretical pro<strong>of</strong>s are conducted for<br />
each component <strong>of</strong> the temporal framework. This would demonstrate that with our<br />
new concepts, innovative strategies <strong>and</strong> algorithms, we can significantly improve the<br />
overall temporal QoS in scientific cloud workflow systems.<br />
This chapter introduces the background, motivations <strong>and</strong> key issues <strong>of</strong> this<br />
research. It is organised as follows. Section 1.1 gives a brief introduction to temporal<br />
QoS in cloud workflow systems. Section 1.2 presents a motivating example from a<br />
scientific application area. Section 1.3 outlines the key issues <strong>of</strong> this research.<br />
Finally, Section 1.4 presents an overview for the remainder <strong>of</strong> this thesis.<br />
1.1 Temporal QoS in Scientific Cloud Workflow Systems<br />
Cloud computing is a latest market-oriented computing paradigm [11, 37]. It refers<br />
to a variety <strong>of</strong> services available on the Internet that delivers computing<br />
functionality on the service provider’s infrastructure. A cloud is a pool <strong>of</strong> virtualised<br />
computer resources <strong>and</strong> may actually be hosted on such as grid or utility computing<br />
environments [7, 59]. It has many potential advantages which include the ability to<br />
1