MPI on the I-WAY: A wide-area, multimethod implementation of the Message Passing Interface

High-speed wide-area networks enable innovative ap-plications that integrate geographically distributed com-puting, database, graphics, and networking resources. The Message Passing Interface (MPI) can be used as a portable, high-performance programming model for such systems. However, the wide-area environment in-troduces challenging problems for the MPI implemen-tor, because of the heterogeneity of both the underlying physical infrastructure and the authentication and soft-ware environment at different sites. In this article, we describe an MPI implementation that incorporates so-lutions to these problems. This implementation, which was developed for the I- WAY distributed-computing ex-periment, was constructed by layering MPICH on the Nexus multithreaded runtime system. Nexus provides automatic configuration mechanisms that can be used to select and configure authentication, process creation, and communication mechanisms in heterogeneous sys-tems. 1