What we DO need to make Desktop Grids a Success in Practice Michela Taufer UCSD - TSRI

The Microsecond Barrier Problem in Molecular Dynamics Chemistry phenomena may occur over long timescales from microseconds to milliseconds Molecular dynamics calculations:  as a powerful and accurate method to study these phenomena  limited to nanoseconds due to lack of compute resources “Microsecond barrier can be overcome for molecular dynamics running on expensive supercomputers for many months.” [Duan and Kollman]

Problems with using Supercomputers Traditional supercomputers and powerful clusters provide computing power only at an excessive cost and resources contentions timeResource utilizationResource contentionWaiting for resources

Desktop Grids Desktop grids provide cost-efficient computing solutions to resource demands of existing scientific applications. Desktop grids  desktop PCs connected to the Internet and Intranets Their number is large and still growing 80%-90% of their CPU time is idle time Advantage of commodity-priced hardware and open-source software offers good price/performance ratio

Who should adapt itself? Should applications adapt to the grid environments? Should the grid adapt to the applications? Scientific applications are usually designed for homogenous, specific computing platforms Desktop grids are highly heterogeneous, volatile environments

Sandboxing Techniques help with Adaptation Sandboxing techniques provide:  Ease of application integration  Desktop (and application) security  Unobtrusiveness Solution  Desktop grids based on virtual execution environments (sandbox) in which native binary applications execute. Grid platforms should adapt to existing applications as much as possible

Handling Performance and Scalability despite Sandboxes Combination of desktop grids and sandboxing makes resource handling a challenging task because:  Physical and virtual environments do not correspond  Compute nodes are highly volatile For sake of performance and scalability we need:  Discovery of available resources among volatile nodes  Selection of resources based on real information at runtime Automatic and transparent methods integrated into grids to capture real information of volatile resources

Conclusion Desktop grids based on sandboxing techniques are the solution to the the increasing demand for compute power of existing scientific applications Sandbox techniques allow researchers to easily integrate existing applications on desktop grids guaranteeing security and unobtrusiveness Research and implementation of transparent and automatic tools for discovery and selection of real resources as an integrated part of desktop grids based on sandboxing techniques