Information Technology Reference
In-Depth Information
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Grid infrastructure
refers to the combination of hardware and Grid middleware
that transforms single pieces of hardware and data resources into an integrated
virtualized infrastructure which is exposed to the user as a single computer
despite of heterogeneity of the underlying infrastructure.
•
Utility computing
is the provision of Grid Computing and applications as a
service either as an open Grid utility or as a hosting solution for one organization
or VO. Utility computing is based on pay-per-use business models.
Grid Computing has evolved into an important discipline within the computer
industry by differentiating itself from distributed computing through an increased
focus on the “Grid problem”, i.e., resource sharing, coordination, manageability,
and high performance (Foster et al. 2001). Thus, the following resources cannot be
considered as Grids, unless they are based on sharing: clusters, network-attached
storage devices, scientific instruments, networks. However, they can be important
components of a Grid.
Grid Computing needs to be distinguished also from HPC. It focuses on resource
sharing and can result in HPC, whereas HPC does not necessarily involve sharing
of resources.
To summarize, Grid Computing is a new computing paradigm based on IT
resource sharing and on provisioning of IT resources and computing in a way
similar to how electricity is consumed today. It is enabled by specific Grid middle-
ware provided on the market either as packaged or open source software, or in form
of utility computing.
3.3 Grid Architectures and Functionality
A Grid architecture provides an overview of the Grid components, defines the
purpose and functions of its components, and indicates how the components interact
with one another (Joseph et al. 2004). The main focus of a Grid architecture is on
the interoperability and protocols among providers and users of resources in order to
establish the sharing relationships. According to Foster and Kesselman (2004), the
required protocols are organized in layers as presented in figure 3.1:
Grid
Protocol
Architecture
Application
Application
Internet
Protocol
Architecture
Collective
Resource
Transport
Connectivity
Internet
Fabric
Link
Fig. 3.1:
Generic Grid architecture (adapted from Foster et al. 2001)
