Grid Basics - Grid and Cloud Computing - page 20

In a comprehensive Grid market study, Insight Research defined Grid Computing
as “a form of distributed system wherein computing resources are shared across
networks” (Insight Research 2006). Other authors have interpreted the new focus
of Grid in the context of specific application. For example, Resch (2006) defined
Grid as “an infrastructure built from hardware and software to solve scientific and
industrial simulation problems.”
The Grid Expert Group coined the term Business Grids and defined and described
Grid as a specific infrastructure:
“We envision Business Grids as the adaptive service-oriented utility infrastructure for
business applications. They will become the general ICT backbone in future economies,
thus achieving profound economic impact.” (NESSI-Grid 2006)
The first successes with national Grids in the area of eScience as well as with open
initiatives such as for example Seti@Home gave rise to further scenarios towards
utility computing, or provision of computing power and applications as a service
(see also Rappa 2004). It became evident that Grid Computing uses Internet as a
transport and communication medium and is a further generalisation of the Web
as it extends the class of accessible resources with applications, data, computing
resources, instruments, sensors and similar (Geiger 2006). Inspired by the electrical
power grid's pervasiveness, ease of use, and reliability, computer scientists in the
mid-1990s began exploring the design and development of an analogous infrastruc-
ture called the computational power Grid enabling access to computing power and
application at any time or place as needed without the need to own the infrastructure
necessary to produce the service (Buyya et al. 2005).
The different definitions propagated by industry, academics and analysts resulted
in a big terminological confusion in the market over the meaning of the terms Grid
and Grid Computing. For the purpose of this topic, we will use the following defi-
nitions:
• Grid middleware is specific software, which provides the necessary function-
ality required to enable sharing of heterogeneous resources and establishing of
virtual organizations. From a market perspective, Grid middleware is a specific
software product that is offered on the market under certain licensing condi-
tions and which is installed and integrated into the existing infrastructure of the
involved company or companies. Grid middleware provides a special virtualiza-
tion and sharing layer that is placed among the heterogeneous infrastructure and
the specific user applications using it.
• Grid Computing is basically the deployed Grid middleware or the computing
enabled by Grid middleware based on flexible, secure, coordinated resource
sharing among a dynamic collection of individuals, institutions, and resources.
Grid Computing means on the one hand that heterogeneous pools of servers,
storage systems and networks are pooled together in a virtualized system
that is exposed to the user as a single computing entity . On the other hand, it
means programming that considers Grid infrastructure and applications that are
adjusted to it.