On the Design of a Demand-Based Network-Computing System: The Purdue University Network-Computing Hub

Many of the systems that currently allow computing on the web target speciic tools. Such solutions tend to be non-reusable in spite of the fact that they involve a signiicant amount of duplicated eeort. This paper describes the issues involved in the design of a demand-based network-computing system, and presents an operational prototype (the Purdue University Network-Computing Hubs, or PUNCH) that allows users to access and run existing software tools via standard worldwide web browsers. The tools do not have to be written in any particular language, and access to source-code is not required. The PUNCH infrastructure can be distributed in a manner that allows tools to be (user-transparently) executed wherever they reside. Currently , PUNCH contains over thirty tools from eight universities and four vendors, and serves more than 500 users. During the past three years, PUNCH users have logged more than 860,000 hits and have performed over 54,000 simulations.