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The Interoperable Message Passing Interface (IMPI) Extensions to LAM/MPI



J M. Squyers, A Lumsdaine, William L. George, John G. Hagedorn, J E. Devaney


Interoperable Message Passing Interface (IMPI) is a protocol specification to allow multiple MPI implementations to cooperate on a single MPI job. Unlike portable MPI implementations, an IMPI-connected parallel job allows the use of vendor-tuned message passing libraries on given target architectures, thus potentially allowing higher levels of performance than previously possible. Additionally, the IMPI protocol uses a low number of connections, which may be suitable for parallel computations across WAN (wide area network) distances. The IMPI specification defines a low-level wire protocol when communicating with a remote MPI implementation. When running IMPI jobs, the only change visible to the user is the sequence of steps necessary to run the job; any correct MPI program will run correctly under IMPI. In this paper, we provide an overview of IMPI, describe its incorporation into the LAM (Local Area Multicomputer) implementation of MPI, and show an example of its use.
MPI Developer¿s Conference


distributed processing, heterogenous computing, message passing, MPI, parallel processing


Squyers, J. , Lumsdaine, A. , George, W. , Hagedorn, J. and Devaney, J. (2001), The Interoperable Message Passing Interface (IMPI) Extensions to LAM/MPI, MPI Developer¿s Conference, [online], (Accessed April 24, 2024)
Created February 28, 2001, Updated October 12, 2021