Grid resource discovery using small world overlay graphs

Abstract

Computational grids are believed to be an effective and scalable solution to the problem of resource sharing over large, heterogeneous networks of computing devices. Since grids are highly distributed in nature, one of the most challenging problems is the discovery of dynamic resources in a grid. In this paper we use ideas from P2P systems to propose a solution for the problem. Specifically, we classify nodes as consumers and producers, depending on whether they consume or produce more jobs. Our algorithm connects all producer nodes using a overlay network that is a small-world graph (the graph is produced by adding "shortcut" chords to a circle). The consumer nodes hang off the small world graph. The producer nodes are forced to take part in resource cataloging and discovery. This has three distinct advantages - first, it prevents "freeloading" by forcing producers to do useful work; second, it frees the consumers to only do computations; third, the low diameter of the overlay graph ensures that all resources are within a small number of hops. We simulate and evaluate the performance of our algorithm in realistic traffic conditions. We evaluate the performance of our algorithm using metrics like the average time to answer the query, the average number of requests that were dropped and the average number of hops traveled by query packets. Our experiments show that our algorithm performs well with thousands of nodes