On 7 October 2015 at 14:54, simona bellavista <afy...@gmail.com> wrote: > I have written a small code in python 2.7 for launching 4 independent > processes on the shell viasubprocess, using the library mpi4py. I am getting > ORTE_ERROR_LOG and I would like to understand where it is happening and why. > > This is my code: > > #!/usr/bin/python > import subprocess > import re > import sys > from mpi4py import MPI > > def main(): > root='base' > comm = MPI.COMM_WORLD > if comm.rank == 0: > job = [root+str(i) for i in range(4)] > else: > job = None > > job = comm.scatter(job, root=0) > cmd="../../montepython/montepython/MontePython.py -conf > ../config/default.conf -p ../config/XXXX.param -o ../chains/XXXX -N 10000 > > XXXX.log" > > cmd_job = re.sub(r"XXXX", job, cmd) > subprocess.check_call(cmd_job, shell=True) > return > > if __name__ == '__main__': > main() > > I am running with the command: > > mpirun -np 4 ./run.py > > This is the error message that I get: > > [localhost:51087] [[51455,0],0] ORTE_ERROR_LOG: Not found in file > base/odls_base_default_fns.c at line 1762 > [localhost:51087] [[51455,0],0] ORTE_ERROR_LOG: Not found in file > orted/orted_comm.c at line 916 > [localhost:51087] [[51455,0],0] ORTE_ERROR_LOG: Not found in file > base/odls_base_default_fns.c at line 1762 > [localhost:51087] [[51455,0],0] ORTE_ERROR_LOG: Not found in file > orted/orted_comm.c at line 916 > -------------------------------------------------------------------------- > A system call failed during shared memory initialization that should > not have. It is likely that your MPI job will now either abort or > experience performance degradation. > > Local host: localhost > System call: open(2) > Error: No such file or directory (errno 2) > -------------------------------------------------------------------------- > > > I cannot understand where the error is happening. MontePython by itself > should not use mpibecause it should be serial. >
This is likely related to a bad interaction between the way Python's subprocess is implemented and the MPI implementation. Anyway, you should not use mpi4py for such a simple trivial parallelism, I recommend you to take a look at Python's multiprocessing module. If for any reason you want to go the MPI way, you should use MPI dynamic process management, e.g. MPI.COMM_SELF.Spawn(...). -- Lisandro Dalcin ============ Research Scientist Computer, Electrical and Mathematical Sciences & Engineering (CEMSE) Numerical Porous Media Center (NumPor) King Abdullah University of Science and Technology (KAUST) http://numpor.kaust.edu.sa/ 4700 King Abdullah University of Science and Technology al-Khawarizmi Bldg (Bldg 1), Office # 4332 Thuwal 23955-6900, Kingdom of Saudi Arabia http://www.kaust.edu.sa Office Phone: +966 12 808-0459
