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DAILY NEWS AND INFORMATION
FOR THE GLOBAL GRID COMMUNITY / SEPTEMBER 8, 2003: VOL. 2 NO. 36
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Special Features:
GRID COMPUTING USING
INDUSTRY-STANDARD WEB SERVICES
Cornell University professors Keshav Pingali, Steve Vavasis and Tony
Ingraffea, and research associates Paul Stodghill, Gerd Heber and Rob Cronin
have successfully demonstrated a geographically-distributed simulation system,
based on industry-standard Web Services, for solving coupled
fluid/thermal/mechanical fracture problems.
"Grid computing is a metaphor representing many styles of distributed
computing," said Cornell's India Professor of Computer Science Keshav Pingali,
who is also an associate director at the Cornell Theory Center. "What we have
shown is that some of the more useful styles of Grid computing can be done
quite effectively using existing industry-standard protocols and software such
as SOAP and XML."
The path to discovery The breakthrough was made in the course of
implementing
the Adaptive Software Project (ASP), a multi-institutional, multi-disciplinary
computational science project, which is studying adaptivity in computational
science applications. Researchers from the University of Alabama, Mississippi
State University, Ohio State University, the College of William and Mary and
Clark-Atlanta University are partnering with Cornell in this project.
The benefits of the ASP approach of using industry-standard Web Services
became evident while the team was exploring a simulation of a fracture in
rocket engine components, such as those used in the space shuttle. These
components transport high-pressure, high-velocity chemically reacting gases,
which can create large thermo-mechanical stresses on component walls. To
simulate fracture initiation and growth, the group had to integrate a number
of large software systems, including a finite-element mesh generation code
developed jointly by Cornell and the College of William and Mary, a
chemically-reacting flow simulation code developed at MSU's Engineering
Research Center and the University of Alabama, and a linear elastic fracture
code developed at CTC.
"The traditional approach to integrating such software modules is to port
all
of them to a single computing platform," said Pingali. "Not only is this very
time-consuming, but every time a new release of a module becomes available,
some poor soul has to repeat the entire process of downloading and porting the
code, re-compiling it, re-linking the compiled code with the rest of the
software, and so on."
To simplify the job of integrating software components while respecting
individual software developers' choices of hardware platforms, operating
systems, and programming languages, the ASP team decided to deploy each major
component as a Web Service running on a server at the institution where that
component was developed. The flow simulation code for example runs on an IBM
x330 Linux server at MSU, while the fracture simulation code runs on CTC's
Windows cluster. The team uses industry-standard Web Service implementations
such as Apache SOAP, and XML-based data exchange formats developed by
Professor Steve Vavasis of the Cornell Computer Science Department.
"We view the person running the simulation as a client who writes a few
hundred lines of code to invoke the various Web Services to orchestrate the
simulation," said research associate Paul Stodghill, who wrote software for
deploying legacy Unix codes as Web Services. "Our motto is 'write once, run
from anywhere.'" He said that the overhead of using geographically-distributed
Web Services for their simulation is about 10 percent.
Tony Ingraffea, the Dwight D. Baum Professor of Civil Engineering at
Cornell
and CTC Associate Director, feels that this overhead is worth paying. "Most
applications people are not interested in using geographically-distributed
computers to solve a large linear system, for example," said Ingraffea. "What
we need is a way of building virtual organizations within which project
members can work with each other's codes easily, while being sensitive to
intellectual property issues."
Gordon Bell, senior researcher at Microsoft's Bay Area Research Center,
concurs. "This project demonstrates the potential of a new way to build
applications and the potential for a new software industry structure based on
delivering results," he said. "Users don't have to buy apps programs and
maintain a more complex software environment; they simply call a program or
database. This is one of the few projects that I would call a Web Service,
and it is well beyond what is running on today's experimental Grid."
Frederica Darema, Senior Science and Technology Advisor in the CISE
Directorate at NSF, is the cognizant NSF official for the ASP project. "It is
to the credit of the scientists working on this project that they have
developed such a cohesive collaboration," she said. "I am pushing for a new
paradigm in application simulation and measurement capabilities called Dynamic
Data Driven Application Systems, and the ASP model of multidisciplinary
collaboration, together with the technology advances made by the project, are
essential for enabling this new paradigm. I am very pleased with the outcomes
of this project and its broader impact."
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