You still need a rendezvous of some kind for comm_connect to work. If you want to try using the file-based method from early MPI days, you can try it - haven’t seen anyone test it in some time, and so I honestly don’t know if it will work.
You’d still require some way of telling the application how many procs are involved and where they are located… > On Jul 8, 2016, at 2:53 PM, Supun Kamburugamuve <skamburugam...@gmail.com> > wrote: > > I guess this is client server. Can we do communications collective > communications with this approach? > > Thanks, > Supun.. > > On Fri, Jul 8, 2016 at 5:37 PM, Jeff Hammond <jeff.scie...@gmail.com > <mailto:jeff.scie...@gmail.com>> wrote: > Why wouldn't https://www.open-mpi.org/doc/v1.8/man3/MPI_Comm_connect.3.php > <https://www.open-mpi.org/doc/v1.8/man3/MPI_Comm_connect.3.php> and friends > work after MPI_Init is called, regardless of how the process is spawned? > > Jeff > > On Fri, Jul 8, 2016 at 9:55 AM, Ralph Castain <r...@open-mpi.org > <mailto:r...@open-mpi.org>> wrote: > You’d need to have some rendezvous mechanism. I suppose one option would be > to launch a set of PMIx servers on the nodes (and ensure they know about each > other) to support these things, but that’s all mpirun really does anyway. > > What did you have in mind? > >> On Jul 8, 2016, at 9:49 AM, Supun Kamburugamuve <skamburugam...@gmail.com >> <mailto:skamburugam...@gmail.com>> wrote: >> >> Thanks for the quick response. Is there a way for extending OpenMPI so that >> it can discover the processes using other means? >> >> Supun. >> >> On Fri, Jul 8, 2016 at 12:45 PM, Ralph Castain <r...@open-mpi.org >> <mailto:r...@open-mpi.org>> wrote: >> If not spawned by mpirun, and not spawned by a resource manager, then it >> won’t work. There is no way for the procs to wireup. >> >> >>> On Jul 8, 2016, at 9:42 AM, Supun Kamburugamuve <skamburugam...@gmail.com >>> <mailto:skamburugam...@gmail.com>> wrote: >>> >>> Yes, the processes are not spawned by MPI and they are not spawned by >>> something like Slurm/PBS. >>> >>> How does MPI get to know what processes running in what nodes in a general >>> sense? Do we need to write some plugin so that it can figure out this >>> information? I guess this must be the way it is supporting Slurm/PBS etc. >>> >>> Thanks, >>> Supun.. >>> >>> On Fri, Jul 8, 2016 at 12:06 PM, Ralph Castain <r...@open-mpi.org >>> <mailto:r...@open-mpi.org>> wrote: >>> You mean you didn’t launch those procs via mpirun, yes? If you started them >>> via some resource manager, then you might just be able to call MPI_Init and >>> have them wireup. >>> >>> >>> > On Jul 8, 2016, at 8:55 AM, Supun Kamburugamuve <skamburugam...@gmail.com >>> > <mailto:skamburugam...@gmail.com>> wrote: >>> > >>> > Hi, >>> > >>> > I have a set of processes running and these are not managed/spawned by >>> > Open MPI. Is it possible to use Open MPI as a pure communication library >>> > among these processes? >>> > >>> > Thanks, >>> > Supun.. >>> > _______________________________________________ >>> > users mailing list >>> > us...@open-mpi.org <mailto:us...@open-mpi.org> >>> > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users >>> > <https://www.open-mpi.org/mailman/listinfo.cgi/users> >>> > Link to this post: >>> > http://www.open-mpi.org/community/lists/users/2016/07/29612.php >>> > <http://www.open-mpi.org/community/lists/users/2016/07/29612.php> >>> >>> _______________________________________________ >>> users mailing list >>> us...@open-mpi.org <mailto:us...@open-mpi.org> >>> Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users >>> <https://www.open-mpi.org/mailman/listinfo.cgi/users> >>> Link to this post: >>> http://www.open-mpi.org/community/lists/users/2016/07/29613.php >>> <http://www.open-mpi.org/community/lists/users/2016/07/29613.php> >>> _______________________________________________ >>> users mailing list >>> us...@open-mpi.org <mailto:us...@open-mpi.org> >>> Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users >>> <https://www.open-mpi.org/mailman/listinfo.cgi/users> >>> Link to this post: >>> http://www.open-mpi.org/community/lists/users/2016/07/29614.php >>> <http://www.open-mpi.org/community/lists/users/2016/07/29614.php> >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org <mailto:us...@open-mpi.org> >> Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users >> <https://www.open-mpi.org/mailman/listinfo.cgi/users> >> Link to this post: >> http://www.open-mpi.org/community/lists/users/2016/07/29615.php >> <http://www.open-mpi.org/community/lists/users/2016/07/29615.php> >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org <mailto:us...@open-mpi.org> >> Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users >> <https://www.open-mpi.org/mailman/listinfo.cgi/users> >> Link to this post: >> http://www.open-mpi.org/community/lists/users/2016/07/29616.php >> <http://www.open-mpi.org/community/lists/users/2016/07/29616.php> > > _______________________________________________ > users mailing list > us...@open-mpi.org <mailto:us...@open-mpi.org> > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users > <https://www.open-mpi.org/mailman/listinfo.cgi/users> > Link to this post: > http://www.open-mpi.org/community/lists/users/2016/07/29617.php > <http://www.open-mpi.org/community/lists/users/2016/07/29617.php> > > > > -- > Jeff Hammond > jeff.scie...@gmail.com <mailto:jeff.scie...@gmail.com> > http://jeffhammond.github.io/ <http://jeffhammond.github.io/> > _______________________________________________ > users mailing list > us...@open-mpi.org <mailto:us...@open-mpi.org> > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users > <https://www.open-mpi.org/mailman/listinfo.cgi/users> > Link to this post: > http://www.open-mpi.org/community/lists/users/2016/07/29627.php > <http://www.open-mpi.org/community/lists/users/2016/07/29627.php> > > _______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2016/07/29628.php
