What is the Grid?

• In his article "What is the Grid? A Three Point Checklist", Ian Foster lists these primary attributes:
  • Computing resources are not administered centrally.
  • Open standards are used.
  • Nontrivial quality of service is achieved.

• Plaszczak/Wellner define grid technology as "the technology that enables resource virtualization, on-demand provisioning, and service (resource) sharing between organizations."
• IBM defines grid computing as "the ability, using a set of open standards and protocols, to gain access to applications and data, processing power, storage capacity and a vast array of other computing resources over the Internet. A grid is a type of parallel and distributed system that enables the sharing, selection, and aggregation of resources distributed across 'multiple' administrative domains based on their (resources) availability, capacity, performance, cost and users' quality-of-service requirements"
• An earlier example of the notion of computing as utility was in 1965 by MIT's Fernando Corb. Fernando and the other designers of the Multics operating system envisioned a computer facility operating "like a power company or water company". http://www.multicians.org/fjcc3.html
• Buyya/Venugopal define grid as "a type of parallel and distributed system that enables the sharing, selection, and aggregation of geographically distributed autonomous resources dynamically at runtime depending on their availability, capability, performance, cost, and users' quality-of-service requirements".
• CERN, one of the largest users of grid technology, talk of The Grid: "a service for sharing computer power and data storage capacity over the Internet.

Production grids

• Enabling Grids for E-sciencE
• NorduGrid
• Open Science Grid
• OurGrid
• Sun Grid
• Xgrid

Grid computing

Grid computing (or the use of a computational grid) is the application of several computers to a single problem at the same time – usually to a scientific or technical problem that requires a great number of computer processing cycles or access to large amounts of data. According to John Patrick, formerly IBM's vice president for Internet strategies, "the next big thing will be grid computing."

Grid computing depends on software to divide and apportion pieces of a program among several computers, sometimes up to many thousands. Grid computing can also be thought of as distributed and large-scale cluster computing, as well as a form of network-distributed parallel It can be small -- confined to a network of computer workstations within a corporation, for example -- or it can be a large, public collaboration across many companies or networks.

It is a form of distributed computing whereby a "super and virtual computer" is composed of a cluster of networked, loosely coupled computers, acting in concert to perform very large tasks. This technology has been applied to computationally intensive scientific, mathematical, and academic problems through volunteer computing, and it is used in commercial enterprises for such diverse applications as drug discovery, economic forecasting, seismic analysis, and back-office data processing in support of e-commerce and Web services.

What distinguishes grid computing from conventional cluster computing systems is that grids tend to be more loosely coupled, heterogeneous, and geographically dispersed. Also, while a computing grid may be dedicated to a specialized application, it is often constructed with the aid of general-purpose grid software libraries and middleware.

At its most basic level, grid computing is a computer network in which each computer's resources are shared with every other computer in the system. Processing power, memory and data storage are all community resources that authorized users can tap into and leverage for specific tasks. A grid computing system can be as simple as a collection of similar computers running on the same operating system or as complex as inter-networked systems comprised of every computer platform you can think of.

The grid computing concept isn't a new one. It's a special kind of distributed computing. In distributed computing, different computers within the same network share one or more resources. In the ideal grid computing system, every resource is shared, turning a computer network into a powerful supercomputer. With the right user interface, accessing a grid computing system would look no different than accessing a local machine's resources. Every authorized computer would have access to enormous processing power and storage capacity.

Grid Compass

he Grid Compass 1100 arguably the first laptop computer, introduced in April 1982.

The computer was designed by British industrial designer Bill Moggridge in 1979, and first sold three years later. The design used a clamshell case (where the screen folds flat to the rest of the computer when closed), which was made from a magnesium alloy. The computer featured an Intel 8086 processor, a 320x200-pixel (CGA) electroluminescent display, 340-kilobyte magnetic bubble memory, and a 1200 bit/s modem. Devices like hard drives and floppy drives could be connected via the 488 I/O (also known as the GPIB or General Purpose Instrumentation Bus). This port made it possible to connect multiple devices in a daisy-chain. It weighed 5 kg (11 lb).

As a groundbreaking design, the Compass ran Grid-OS, its very own operating system. Its specialized software and high price (US$ 8-10,000) meant that it was limited to specialized applications. The main buyer was the U.S. government. NASA used it on the Space Shuttle during the early 1980s, as it was both powerful and lightweight. The military Special Forces also purchased the machine, as it could be used by paratroopers in combat.

Along with the Gavilan SC and Sharp PC-5000 released the following year, the Grid Compass established much of the basic design of subsequent laptop computers, although the laptop concept itself owed much to the Dynabook project developed at Xerox PARC from the late 1960s. The Compass company subsequently earned significant returns on its patent rights as its innovations became commonplace. The first popular portable computer was the Osborne 1, sold at around the same time as the GRiD; it lacked the Compass's refinement and small size, but it was much more affordable and ran the popular CP/M operating system.