I'm having an issue with MPI_Comm_spawn not starting workers on the nodes provided via -machinefile or -host. This is occurring on Ubuntu 14.04/14.10 with openMPI 1.6.5. However, I do not have the problem on Ubuntu 12.04 with openMPI 1.4.3 nor is there a problem when I install openMPI 1.8.4 from source on Ubuntu 14.04.
Any suggestions as to what is going on? We can install from source to deal with this, but Ubuntu 14.04/14.10/15.04 (and I think the current Debian) are all relying on 1.6.5 so this issue might affect many others. As far as I can tell there aren't any threads on the mailing lists or info in the NEWS file that relate to this. Here's a reproducible test case. In the attached zip file, parent.cpp generates an executable that simply tries to spawn workers using MPI_Comm_spawn and the child executable simply reports what nodes the workers are operating on. I compile and run the program as: mpicxx -o child child.cpp mpicxx -o parent parent.cpp mpirun -host smeagol,arwen,smeagol,arwen -np 1 parent And the result is as follows with all children on the original node: Starting: I'm process 0 and we are 1 Finishing: I'm process 0 and we are 1 I'm child process 0 on smeagol and we are 3 I'm child process 1 on smeagol and we are 3 My parent communicator size is: 3 I'm child process 2 on smeagol and we are 3 My parent communicator size is: 3 My parent communicator size is: 3 This is all on pretty standard Ubuntu 14.04, with openMPI installed from Ubuntu (libopenmpi-dev, libopenmpi1.6, openmpi-bin) I've included in the zip file: * parent.cpp and child.cpp * ompi_info --all on the master * ompi_info -v ompi full --parsable on all nodes * PATH and LD_LIBRARY_PATH info * ifconfig information -Chris ---------------------------------------------------------------------------------------------- Chris Paciorek Statistical Computing Consultant Statistical Computing Facility, Econometrics Laboratory, Berkeley Research Computing Office: 495 Evans Hall Email: pacio...@stat.berkeley.edu Mailing Address: Voice: 510-842-9056 Department of Statistics Fax: 510-642-7892 367 Evans Hall Skype: cjpaciorek University of California, Berkeley WWW: www.stat.berkeley.edu/~paciorek Berkeley, CA 94720 USA Permanent forward: pacio...@alumni.cmu.edu
