The Anatomy of the Grid - Enabling Scalable Virtual Organizations

TL;DR

The authors present an extensible and open Grid architecture, in which protocols, services, application programming interfaces, and software development kits are categorized according to their roles in enabling resource sharing.

Abstract

"Grid" computing has emerged as an important new field, distinguished from conventional distributed computing by its focus on large-scale resource sharing, innovative applications, and, in some cases, high-performance orientation. In this article, we define this new field. First, we review the "Grid problem," which we define as flexible, secure, coordinated resource sharing among dynamic collections of individuals, institutions, and resources-what we refer to as virtual organizations. In such settings, we encounter unique authentication, authorization, resource access, resource discovery, and other challenges. It is this class of problem that is addressed by Grid technologies. Next, we present an extensible and open Grid architecture, in which protocols, services, application programming interfaces, and software development kits are categorized according to their roles in enabling resource sharing. We describe requirements that we believe any such mechanisms must satisfy, and we discuss the central role played by the intergrid protocols that enable interoperability among different Grid systems. Finally, we discuss how Grid technologies relate to other contemporary technologies, including enterprise integration, application service provider, storage service provider, and peer-to-peer computing. We maintain that Grid concepts and technologies complement and have much to contribute to these other approaches.

Figures (5)

• Figure 1: An actual organization can participate in one or more VOs by sharing some or all of the resources that the actual organization controls. We show three actual organizations (the circles), and two VOs: P , which links participants in an aerospace design consortium, and Q , which links colleagues who have agreed to share space cycles. One actual organization participates in P , the second participates in Q , and the third is a member of both P and Q . The policies governing access to resources (summarized in "quotes") vary according to the actual organizations, resources, and VOs involved.
• Figure 2: The layered Grid architecture and its relationship to the Internet protocol architecture. Because the Internet protocol architecture extends from network to application, there is a mapping from Grid layers into Internet layers.
• Figure 3: Collective and Resource layer protocols, services, APIs, and SDKS can be combined in a variety of ways to deliver functionality to applications.
• Figure 4: Software development kits (SDKs) implement specific APIs. These APIs in turn use Grid protocols to interact with network services that provide capabilities to the end user. Higher level SDKs can provide functionality that is not directly mapped to a specific protocol, but may combine protocol operations with calls to additional APIs as well as implement local functionality.
• Figure 5: On the left, an API is used to develop applications that can target either Kerberos or PKI security mechanisms. On the right, protocols (the Grid Security Protocols) are used to enable interoperability between Kerberos and PKI domains.