Information Technology Reference
In-Depth Information
2.2
Exploring the Vision of Green Utility Computing Model
The challenge of any research is not to just recognise the issues, but to know what can
be done, how it can be done, and to identify certain solutions or at least directional
recommendations towards solutions.
It is not enough to know that ICT being pervasive has been changing our lives, and
different sectors of the economy such as manufacturing, business and transportation
sectors. Implementing and operating utility computing might change even more, and
ultimately an integrated approach which can influence the practices through
environmental policies of green ICT of an organisation is needed. Bose and Luo
(2011) have defined from the theoretical perspective a framework for the assessment
of the potential of the organisation to undertake green ICT initiative especially using
virtualization and cloud computing. This framework considers the organisational,
technological and environmental perspectives attempting to create synergies that will
increase the likelihood that companies will successfully implement green utility
computing initiatives [13].
3
ICT as a Utility in the Cloud
3.1
Why Cloud Computing for Utility Computing?
Cloud computing has the foundation in distributed computing implemented usually
using service oriented architecture and grid computing [14], [15]. Buyya et al. (2009)
have provided the following description [6] “A cloud is a type of parallel and
distributed system consisting of a collection of inter-connected and virtualized
computers that are dynamically provisioned and presented as one or more unified
computing resource(s) based on service-level agreements established through
negotiation between the service provider and consumers.'' The distributed computing
and mobile technologies have been already experimented for utility computing and
these cover the essential requirements of utility computing. Moreover the National
Institute of Standards and Technologies (NIST) has emphasized the elasticity feature
of computing resources in their definition of cloud computing [16] that is largely
accepted and frequently cited. This definition is as follows: “Clouds are a large pool
of easily usable and accessible virtualized resources (such as hardware, development
platforms and/or services)”.
Cloud Computing has resulted from the convergence of Grid Computing, and
computing services, and represents the contemporary trend towards the external
deployment of ICT resources, such as computational power, storage or business
applications, and obtaining them as services. These resources can be dynamically re-
configured to adjust to a variable load (scale), allowing also for an optimum resource
utilization that are needed for utility computing. This pool of resources is typically
exploited by a pay-per-use model in which guarantees are offered by the
infrastructure provider by means of customized Service Level Agreements [17].
Grace (2010) has made explicit the distinctions between clouds, service oriented
architecture and grid computing [18]. However the delimitation line is very narrow
and particularly, with grid computing. Also a cloud infrastructure can be defined on
