Until recently, application developers could often assume a target environment that was (to a useful extent) homogeneous, reliable, secure, and centrally managed. Increasingly, however, computing is concerned with collaboration, data sharing, and other new modes of interaction that involve distributed resources. The result is an increased focus on the interconnection of systems both within and across enterprises, whether in the form of intelligent networks, switching devices, | Copyright Global Grid Forum 2002 . All Rights Reserved. Minor changes to the original have been made to conform with house style. 8 The physiology of the Grid Ian Foster 1 2 Carl Kesselman 3 Jeffrey M. Nick 4 and Steven Tuecke1 1 Argonne National Laboratory Argonne Illinois United States 2 University of Chicago Chicago Illinois United States 3 University of Southern California Marina del Rey California United States 4IBM Corporation Poughkeepsie New York United States INTRODUCTION Until recently application developers could often assume a target environment that was to a useful extent homogeneous reliable secure and centrally managed. Increasingly however computing is concerned with collaboration data sharing and other new modes of interaction that involve distributed resources. The result is an increased focus on the interconnection of systems both within and across enterprises whether in the form of intelligent networks switching devices caching services appliance servers storage systems or storage area network management systems. In addition companies are realizing that they can achieve significant cost savings by outsourcing nonessential elements of their IT environment to various forms of service providers. These evolutionary pressures generate new requirements for distributed application development and deployment. Today applications and middleware are typically developed Grid Computing - Making the Global Infrastructure a Reality. Edited by F. Berman A. Hey and G. Fox 2003 John Wiley Sons Ltd ISBN 0-470-85319-0 218 IAN FOSTER ETAL. for a specific platform . Windows NT a flavor of Unix a mainframe J2EE Microsoft .NET that provides a hosting environment for running applications. The capabilities provided by such platforms may range from integrated resource management functions to database integration clustering services security workload management and problem determination - with different implementations semantic behaviors and application programming
