Basic Concepts

• What is GRID?

In 1998, grid gurus Ian Foster and Carl Kesselman defined the grid as a hardware and software infrastructure that provides dependable, consistent, and pervasive access to high-end computational resources.
· IBM's definition of Grid is "all or some of a group of computers, servers and storage across an enterprise, virtualized as one large computing system".
· For Oracle's Larry Ellison, the grid is "capacity on demand. Plug another server into the grid and the application runs faster and more reliably."

• What is GRID computing?

Grid computing is a form of distributed computing that involves coordinating and sharing computing, application, data, storage, or network resources across dynamic and geographically dispersed organizations.
Ian Foster and Carl Kesselman stated that grid computing is concerned with coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organizations.
However,the the definition of GRID computing keeps shifting. The technologies and standards surrounding grid computing are still evolving.
More detailed definition can be found here:
http://www-fp.mcs.anl.gov/~foster/Articles/WhatIsTheGrid.pdf

• What is GRID architecture / infrastructure?

GRID unifies all existing technologies in this area, such as clustering, peer-to-peer. It lies on top of the infrastructure by providing modules that form the Grid operating system. Major components include:

1. a dynamic resources directory,
2. a distributed data management system,
3. an application runtime and monitoring system,
4. informaiton services, and
5. security services.

Above this infrastructure are many applications GRID technology provide. More detailed information please refer to: http://www.globus.org/research/testbeds.html

• What is the difference between GRID & Cluster?

Cluster can constitute a powerful Grid resource. However, such a system is not a Grid itself, due to its centralized control of the hosts that it manages: it has complete knowledge of system state and user requests,and complete control over individual components.
GRID, unlike cluster, integrates and coordinates resources and users that live within different control domains—geographically distributed and heterogeneous.

• Who are the players (industry) in this field now?

Some examples include: Automotive and aerospace, for collaborative design and data-intensive testing; financial services, for running long, complex scenarios and arriving at more accurate decisions; life sciences, for analyzing and decoding strings of biological and chemical information; government, for enabling seamless collaboration and agility in both civil and military departments and agencies; higher education for enabling advanced, data and compute intensive research.

• What are the possible benefits (motives) of implementing GRID?

Benefits can be extensive. They include:
· Accelerated time to results, which allows for the provisioning of extra time and resources to solve problems that were previously unsolvable

· Improved productivity and collaboration

· Allowing widely dispersed departments and businesses to create virtual organizations to share data and resources

· More flexible, resilient operational infrastructures

· Instantaneous access to compute and data resources to "sense and respond" to needs

· Leveraging existing capital investments, which helps to ensure optimal utilization of computing capabilities

· Avoiding common pitfalls of over-provisioning and incurring excess costs

· Freeing IT organizations from the burden of administering disparate, non-integrated systems

. Enormous computation resources for everyone.

• What other technologies are needed to help its development? the relationship between them?

GRID can be seen as the latest and most complete evolution of more familiar developments, such as: distributed computing, the Web, clustering, peer-to-peer and virtualization technologies.
· Like the Web, grid computing keeps complexity hidden: multiple users enjoy a single, unified experience.

· Unlike the Web, which mainly enables communication, grid computing enables full collaboration toward common business goals.

· Like peer-to-peer, grid computing allows users to share files.

· Unlike peer-to-peer, grid computing allows many-to-many sharing — not only files but other resources as well.

· Like clusters and distributed computing, grids bring computing resources together.

· Unlike clusters and distributed computing, which need physical proximity and operating homogeneity, grids can be geographically distributed and heterogeneous.

· Like virtualization technologies, grid computing enables the virtualization of IT resources.

· Unlike virtualization technologies, which virtualize a single system, grid computing enables the virtualization of vast and disparate IT resources.