Weaving computational grids: how analogous are they with electrical grids?

Following Alessandro Volta’s invention of the electrical battery in 1800, Thomas Edison paved the way for electricity’s widespread use by inventing the electric bulb. Figure 1 shows Volta demonstrating the battery for Napoleon I in 1801 at the French National Institute, Paris. Whether or not Volta envisioned it, his invention evolved into a worldwide electrical power grid that provides dependable, consistent, and pervasive access to utility power and has become an integral part of modern society. We are now witnessing rapid developments in computer networks and distributed and highperformance computing. Inspired by the electrical power grid’s pervasiveness and reliability, computer scientists in the mid-1990s began exploring the design and development of a new infrastructure, computational power grids for network computing.1 Emerging computational grids currently serve scientists working on largescale, dataand resource-intensive applications that require more computing power than a computer, a supercomputer, or a cluster can provide in a single domain. This need for greater computing power has driven advances in scalable computing—from distributed parallel computing on local-area networks of PCs and workstations (cluster computing)2,3 to distributed computing on high-end computers connected by wide-area networks across multiple domains. Computational grids are an extension of the scalable computing concept: Internet-based networks of geographically distributed computing resources that scientists can share, select from, and aggregate to solve large-scale problems. The research and developmental work for implementing such grids is proceeding at a very brisk pace; their performance and ease of use could reach the level of the electrical power grid within a few years. In this article, we describe how computational grids developed, their layered structure, and their emerging operational model, which we envisage as providing seamless, utility-like access to computational resources. We also attempt to show the similarities and dissimilarities between this system, still in its infancy, and the mature electrical power grid. By identifying quantities and parameters that are analogous between the two grids, we hope that we WEAVING COMPUTATIONAL GRIDS: HOW ANALOGOUS ARE THEY WITH ELECTRICAL GRIDS?