Overview of Active Sheets - Spreadsheets supporting supercomputing
Grid computing has great potential but to enter the mainstream it must be simplified. Tools and libraries must make it easier to solve problems by being simpler and at the same time more sophisticated. In this paper we describe how Grid computing can be achieved through spreadsheets. Spreadsheets are important business tools. Increasingly they are being used for simulation e.g. to perform risk analysis. Such tasks have far greater computational demands than traditional spreadsheet bookkeeping applications..
No parallel programming or complex tools need to be used. So long as dependencies allow it, formulae in a spreadsheet can be evaluated concurrently on the Grid. Thus Grid computing becomes accessible to all those who can use a spreadsheet. The story is completed with a sophisticated backend system, NetSolve, which can solve complex linear algebra systems with minimal intervention from the user. In this paper we present the architecture of the system for performing such simple yet sophisticated grid computing and a case study which performs a large singular value decomposition.
ActiveSheets builds on Nimrod by adding a component based spread sheet interface for specifying computational experiments. We have chosen to use Microsoft Excel as the base spreadsheet application, and have used VBA and associated component technology to allow ActiveSheets to interface with Nimrod/G, EnFuzion and NetSolve. NetSolve is a client-server system that enables users to solve complex scientific problems remotely. The system allows users to access both hardware and software computational resources distributed across a network. Some of the goals of the NetSolve project include ease-of-use for the user, efficient use of the resources, and the ability to integrate any arbitrary software component as a resource into the NetSolve system.
The key technical innovation of Active Sheets is a mechanism enabling the concurrent evaluation of spreadsheet functions. Furthermore, the mechanism does not require modification of the standard spreadsheet evaluation engine.