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Grid computing offers a model for solving massive computational problems by making use of the unused CPU cycles of large numbers of disparate, often desktop, computers treated as a virtual cluster embedded in a distributed telecommunications infrastructure. Grid computing's focus on the ability to support computation across administrative domains sets it apart from traditional computer clusters or traditional distributed computing.
Grid computing has the design goal of solving problems too big for any single supercomputer, whilst retaining the flexibility to work on multiple smaller problems. Thus grid computing provides a multi-user environment. Its secondary aims are: better exploitation of the available computing power, and catering for the intermittent demands of large computational exercises.
This implies the use of secure authorization techniques to allow remote users to control computing resources.
Grid computing involves sharing heterogenous resources (based on different platforms, hardware/software architectures, and computer languages), located in different places belonging to different administrative domains over a network using open standards. In short, it involves virtualizing computing resources.
Grid computing is often confused with cluster computing. The key differences are that clusters are homogenous while grids are heterogeneous; also, grids spread out and encompass user desktops while clusters are generally confined to data centers.
Functionally, one can classify grids as:
Three meanings of grid computing
There are three common uses of the term:Grid computing:
- CERN, who were key in the creation of the World Wide Web, talk of The Grid: "a service for sharing computer power and data storage capacity over the Internet.".
- Pragmatically, grid computing is attractive to geographically-distributed non-profit collaborative research efforts like the NCSA Bioinformatics Grids such as BIRN: external grids.
- Grid computing is also attractive to large commercial enterprises with complex compute problems who aim to fully exploit their internal computing power: internal grids.
The Global Grid Forum
The Global Grid Forum (GGF) has the purpose of defining specifications for grid computing. The Globus Alliance implements these standards through the Globus Toolkit, which has become the de facto standard for grid middleware. As a middleware component, it provides a standard platform for services to build upon, but grid computing needs other components as well, and many other tools operate to support a successful Grid environment. This situation resembles that of TCP/IP: the usefulness of the Internet emerged both from the success of TCP/IP and the establishment of applications such as newsgroups and webpages.
Globus has implementations of the GGF-defined protocols to provide:
- Resource management: Grid Resource Allocation & Management Protocol (GRAM)
- Information Services: Monitoring and Discovery Service (MDS)
- Security Services: Grid Security Infrastructure (GSI)
- Data Movement and Management: Global Access to Secondary Storage (GASS) and GridFTP
A number of tools function along with Globus to make grid computing a more robust platform, useful to high-performance computing communities. They include:
- Grid Portal Software such as GridPort and OGCE
- Grid Packaging Toolkit (GPT)
- MPICH-G2 (Grid Enabled MPI)
- Network Weather Service (NWS) (Quality-of-Service monitoring and statistics)
- Condor (CPU Cycle Scavenging) and Condor-G (Job Submission)
Most of the grids which span research and academic communities in North America and Europe utilise the Globus Toolkit as their core middleware.
XML-based web services offer a way to access the diverse services/applications in a distributed environment. As of 2003 the worlds of grid computing and of web services have started to converge to offer Grid as a web service (Grid Service). The Open Grid Services Architecture (OGSA) has defined this environment, which will offer several functionalities adhering to the semantics of the Grid Service.
Grids offer a way to solve Grand Challenge problems like protein folding, financial modelling, earthquake simulation, climate/weather modelling etc. Grids offer a way of using the information technology resources optimally in an organisation. They also provide a means for offering information technology as a utility bureau for commercial and non-commercial clients, with those clients paying only for what they use, as with electricity or water.
Commercial grid computing offerings
Computing vendors have, in the 2000s, begun to offer grid solutions which are either based on the Globus Toolkit, or their own proprietory architecture. Confusion remains: in that vendors may badge their computing on demand or cluster offerings as grid computing.
Key vendors in grid computing:
See also
References
- Ian Foster, Carl Kesselman: The Grid: Blueprint for a New Computing Infrastructure, Morgan Kaufmann Publishers, ISBN 1558604758, Website (http://www.mkp.com/grids/)
- Fran Berman, Anthony J. G. Hey, Geoffrey Fox: Grid Computing: Making The Global Infrastructure a Reality, Wiley, ISBN 0470853190, Online version (http://www.grid2002.org/)
- CERN: The Grid Café - What is Grid? (http://gridcafe.web.cern.ch/gridcafe/whatisgrid/whatis.html), viewed 04 Feb 2005.
External links
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