In the past several years, grid computing has emerged as a way to deploy and take advantage of computing resources across geographies and organizations. This is the brief introduction to Grid computing, not looking into its technical aspect and implimentation part, so what is Grid or Grid computing is ?
Imagine several million computers from all over the world, and owned by thousands of different people. Imagine they include desktops, laptops, supercomputers, data vaults, and instruments like mobile phones, meteorological sensors and telescopes...Now imagine that all of these computers can be connected to form a single, huge and super-powerful computer! This huge, sprawling, global computer is called Grid or Grid Computing.
Grid computing can mean different things to different individuals. The grand vision is often presented as an analogy to power grids where users (or electrical appliances) get access to electricity through wall sockets with no care or consideration for where or how the electricity is actually generated. In this view of grid computing, computing becomes pervasive and individual users (or client applications) gain access to computing resources (processors, storage, data, applications, and so on) as needed with little or no knowledge of where those resources are located or what the underlying technologies, hardware, operating system, and so on are.
Grids cannot be considered as a revolutionary technology. Rather they have evolved from existing technologies such as distributed computing, web services, the Internet, various cryptography technologies providing security features and virtualization technology. As we can see, none of these technologies is completely new. They have existed for quite some time and have been serving various needs. The grid technology takes features from these technologies to develop a system that can provide computational resources for some specific tasks. These tasks can be the simulation of stock markets to predict future trends, scientific research such as prediction of earthquakes or serving business needs for an organization having a geographically distributed presence. So in short, grid is an evolutionary technology, which leverages existing IT infrastructure to provide high throughput computing. Its key values are in the underlying distributed computing infrastructure technologies that are evolving in support of cross-organizational application and resource sharing—in a word, virtualization—virtualization across technologies,platforms, and organizations.
Virtualization in grids refers to seamless integration of geographically distributed and heterogeneous systems. This enables users to make use of the services provided by the grid in a transparent way. This means that the users need not be aware of the location of computing resources. So, from the users’ perspective, there is just one point of entry to the grid system. They just have to submit their service request at this node. Then it is up to the grid system to locate the available computing resources, which can serve the users’ request. “Anatomy of the Grid” introduces the concept of virtual organization (VO). It defines a VO as a “dynamic collection of multiple organizations providing coordinated resource sharing”. The formation of VO is aimed at utilizing computing resources for specific problem solving as discussed earlier. Based on the concept of VOs, we review three terms, which provide background for our understanding of grid systems. The first of these terms is virtualization, which has already been explained and stems from virtual organizations. The second term is heterogeneity. When we talk of VOs, it may imply that we are talking about a multi-institutional entity. The organizations that form part of a VO may have different resources in terms of hardware, operating system and network bandwidth. So, we infer that a VO is a collection of heterogeneous resources. The third term of importance is dynamic. Organizations can join or leave a VO per their requirements and convenience. So a VO is a dynamic entity. These three terms explain why grids have specific requirements as compared to other distributed systems.
Grid computing can mean different things to different individuals. The grand vision is often presented as an analogy to power grids where users (or electrical appliances) get access to electricity through wall sockets with no care or consideration for where or how the electricity is actually generated. In this view of grid computing, computing becomes pervasive and individual users (or client applications) gain access to computing resources (processors, storage, data, applications, and so on) as needed with little or no knowledge of where those resources are located or what the underlying technologies, hardware, operating system, and so on are.
Grids cannot be considered as a revolutionary technology. Rather they have evolved from existing technologies such as distributed computing, web services, the Internet, various cryptography technologies providing security features and virtualization technology. As we can see, none of these technologies is completely new. They have existed for quite some time and have been serving various needs. The grid technology takes features from these technologies to develop a system that can provide computational resources for some specific tasks. These tasks can be the simulation of stock markets to predict future trends, scientific research such as prediction of earthquakes or serving business needs for an organization having a geographically distributed presence. So in short, grid is an evolutionary technology, which leverages existing IT infrastructure to provide high throughput computing. Its key values are in the underlying distributed computing infrastructure technologies that are evolving in support of cross-organizational application and resource sharing—in a word, virtualization—virtualization across technologies,platforms, and organizations.
Virtualization in grids refers to seamless integration of geographically distributed and heterogeneous systems. This enables users to make use of the services provided by the grid in a transparent way. This means that the users need not be aware of the location of computing resources. So, from the users’ perspective, there is just one point of entry to the grid system. They just have to submit their service request at this node. Then it is up to the grid system to locate the available computing resources, which can serve the users’ request. “Anatomy of the Grid” introduces the concept of virtual organization (VO). It defines a VO as a “dynamic collection of multiple organizations providing coordinated resource sharing”. The formation of VO is aimed at utilizing computing resources for specific problem solving as discussed earlier. Based on the concept of VOs, we review three terms, which provide background for our understanding of grid systems. The first of these terms is virtualization, which has already been explained and stems from virtual organizations. The second term is heterogeneity. When we talk of VOs, it may imply that we are talking about a multi-institutional entity. The organizations that form part of a VO may have different resources in terms of hardware, operating system and network bandwidth. So, we infer that a VO is a collection of heterogeneous resources. The third term of importance is dynamic. Organizations can join or leave a VO per their requirements and convenience. So a VO is a dynamic entity. These three terms explain why grids have specific requirements as compared to other distributed systems.
This kind of virtualization in grid is only achievable through the use of open standards. Open standards help ensure that applications can transparently take advantage of whatever appropriate resources can be made available to them. An environment that provides the ability to share and transparently access resources across a distributed and heterogeneous environment not only requires the technology to virtualize certain resources, but also technologies and standards in the areas of scheduling, security, accounting, systems management, and so on
A Grid Checklist
A Grid Checklist
Ian Foster describes a three point checklist to describe a grid. according to which a Grid is a system that:
1) coordinates resources that are not subject to centralized control … (A Grid integrates and coordinates resources and users that live within different control domains—for example, the user’s desktop vs. central computing; different administrative units of the same company; or different companies; and addresses the issues of security, policy, payment, membership, and so forth that arise in these settings. Otherwise, we are dealing with a local management system.)
2) … using standard, open, general-purpose protocols and interfaces … (A Grid is built from multi-purpose protocols and interfaces that address such fundamental issues as authentication, authorization, resource discovery, and resource access. As I discuss further below, it is important that these protocols and interfaces be standard and open. Otherwise, we are dealing with an applicationspecific system.)
3) … to deliver nontrivial qualities of service. (A Grid allows its constituent resources to be used in a coordinated fashion to deliver various qualities of service, relating for example to response time, throughput, availability, and security, and/or co-allocation of multiple resource types to meet complex user demands, so that the utility of the combined system is significantly greater than that of the sum of its parts.)
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