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The San Diego Supercomputer Center (SDSC), in conjunction with the Computer Science and Engineering department at the University of California, San Diego (UCSD), have released the Grid Assessment Probes (GRASP) software package, which gives system architects and applications developers a simple and easy-to-use set of probes for gaining insight into the performance and reliability of grid computing platforms.

Scientists who run data-intensive applications often require access to distributed resources, data repositories and computing facilities that may be located at various sites across the nation or around the world.

"The trend is for information from data acquisition devices - radio telescopes, electron microscopes, and environmental sensors - to grow at rates that exceed Moore's law for the increase in speed of single processors and capacity of single disk drives," said Chaitan Baru, co-director of SDSC's Data and Knowledge Systems (DAKS) program. "Sharing entire systems of processors and storage resources and accessing them on demand helps to keep up with the flood of information. Grid computing provides a promising approach."

GRASP makes it possible to evaluate a grid platform both quantitatively and qualitatively. In developing GRASP, researchers at the Grid Research and Innovation Laboratory (GRAIL) of SDSC and UCSD CSE and the Performance Modeling and Characterization (PMaC) lab at SDSC focused on benchmarks that were representative of data-intensive applications.

"The mission of the Grid Benchmarks Research Group is to promote the efficient use of grids by defining metrics to measure the performance of grid applications and architectures and to rate their functionality and efficiency," said PMaC Laboratory leader Allan Snavely. "These metrics should facilitate good engineering practices by allowing system designers to quantitatively compare alternative implementations. They should also give grid users information about systems capabilities so they can develop and tune their applications."

As a first step towards these goals, GRAIL and PMaC have developed a set of probes that exercise basic grid operations by simulating simple applications. The Grid Assessment Probes test and measure performance of basic grid functions including file transfers, remote execution, and Grid Information Services response. They also can serve as simple grid application examples and test cases.

The SDSC and UCSD researchers have been running the probes on the GrADS testbed, which consists of nearly 100 networked Pentium and IA-64 machines in Tennessee, Illinois, Texas, and California that run variants of the Linux operating system. The researchers have been collecting performance data on the testbed, including compute times, network transfer times, and Globus middleware overhead. The results of these experiments help provide insight into the stability, robustness, and performance of the testbed, and have led to recommendations for future grid software development. GRASP is outlined in paper-and-pencil specification for several typical data-intensive application formats.

"Running the GRASP probes provided a lot of information about the performance and reliability of the grid," said Holly Dail, a programmer analyst in the GRAIL lab. "We were able to observe bottlenecks and weak links, diagnose some failures, and obtain performance expectations for our grid applications."

A reference implementation and a technical report of preliminary measurement results from the probes are available for download at http://grail.sdsc.edu/projects/grasp/. Users can run, copy, modify, and distribute GRASP software and its documentation for educational, research and non-profit purposes without fee, subject to the very simple provisions listed on the website.

"We invite the community to engage with us by running and reporting results from GRASP to better characterize factors affecting the performance of grid applications," said Henri Casanova, director of the GRAIL lab at SDSC.

GRASP was developed under NSF "Strategic Technologies for the Internet" (STI) grant #0230925, "Data Intensive Grid Benchmarks," with Chaitan Baru as Principal Investigator and Allan Snavely and Henri Casanova of SDSC as Co-PIs. This effort is part of larger-scope community activities in the Grid Benchmarks Research group co-founded by PMaC laboratory director Snavely and Rob Van der Wijngaart and Michael Frumkin of NASA, in colloboration with Casanova. For more information see http://grail.sdsc.edu/projects/grasp/.

The Grid Benchmarking Research Group is affiliated with the Global Grid Forum (http://www.gridforum.org/).

The Grid Application Development Software (GrADS) project is developing tools and procedures that make it straightforward for scientists and engineers to construct applications for the Computational Grid, a national network of high performance computer systems. For more information see http://hipersoft.cs.rice.edu/grads/.

The San Diego Supercomputer Center (SDSC) is leading the way in developing a national Cyberinfrastructure that will provide the technological foundation for the next generation of science and engineering advances. Founded in 1985, SDSC is an organized research unit of the University of California, San Diego. With a staff of more than 400 scientists, software developers, and support personnel, SDSC is an international leader in data management, biosciences, geosciences, grid computing and visualization. Primarily funded by the National Science Foundation (NSF), SDSC is the leading-edge site for the National Partnership for Advanced Computational Infrastructure (NPACI), a 41-institution partnership to create computational environments for tomorrow's scientific discovery. For more information, visit http://www.sdsc.edu/.

Media Contact: Greg Lund, SDSC Communications, 858-534-8314,
Technical Contact: Allan Snavely, SDSC and UCSD Computer Science and Engineering, 858-534-5158

Website: http://grail.sdsc.edu/projects/grasp/