Supporting Runtime Tool Interaction for Parallel Simulations

Scientists from many disciplines now routinely use modeling and simulation techniques to study physical and biological phenomena. Advances in high-performance architectures and networking have made it possible to build complex simulations with parallel and distributed interacting components. Unfortunately, the software needed to support such complex simulations has lagged behind hardware developments. We focus here on one aspect of such support: runtime program interaction. We have developed a runtime interaction framework and we have implemented a specific instance of it for an application in seismic tomography. That instance, called TierraLab, extends the geoscientists' existing (legacy) tomography code with runtime interaction capabilities which they access through a MATLAB interface. The scientist can stop a program, retrieve data, analyze and visualize that data with existing MATLAB routines, modify the data, and resume execution. They can do this all within a familiar MATLAB-like environment without having to be concerned with any of the low- level details of parallel or distributed data distribution. Data distribution is handled transparently by the Distributed Array Query and Visualization (DAQV) system. Our framework allows scientists to construct and maintain their own customized runtime interaction system.