From: Thilo Kielmann Newsgroups: comp.parallel.mpi Subject: Re: Using MPI Across LANS and Domains? Date: Mon, 16 Nov 1998 18:15:16 +0100 Organization: Vrije Universiteit, Amsterdam Message-Id: <36505DA4.C8A7846C@cs.vu.nl> References: <364303F6.EC921BBD@LL.MIT.EDU> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Michael Starkie wrote: > Is it possible to use MPI to communicate with hosts residing in > different domains across an internet or on different LANS? > > i.e., a machines file of the form: > > workstation1.mcs.anl.gov > mysystem.ll.mit.edu > someother.megahertz.njit.edu > Technically, this is of course possible. Your question is related to how MPI is implemented.To what I know about MPICH , it should definitely work. You just have to set up the right permissions (e.g. .rhosts files) and it should work. A different story is how efficient your programs will run in such a setting, because of high latency and low bandwidth of the wide area links between the domains you connect. If you are using MPI's collective communication operations, our work might be of help to you. We just implemented a library called MagPIe which optimizes collective operation for the case of multiple clusters (or LANs) connected via wide area networks. MagPIe is designed as a plug-in for MPICH; you simply have to link your applications with our library to use it. If you like, you may have a look at: http://www.cs.vu.nl/albatross/ There, you can download MagPIe's source as well as a paper describing it. Hope that helps, Thilo -- Dr. Thilo Kielmann Dept. of Mathematics and Computer Science, Vrije Universiteit De Boelelaan 1081a, 1081 HV Amsterdam, The Netherlands Phone: +31 20 44 47789 /\,/\ Fax: +31 20 44 47653 / u u \ E-Mail: Thilo.Kielmann@acm.org \<_Y_>/ WWW: http://www.cs.vu.nl/~kielmann/ / " \