I'm trying to run a DoE in parallel on a distributed code, which doesn't seem to work. Below is a simplified example that raises the same error as for the real code.
import numpy as np
from openmdao.api import IndepVarComp, Group, Problem, Component
from openmdao.core.mpi_wrap import MPI
from openmdao.drivers.latinhypercube_driver import LatinHypercubeDriver
if MPI:
from openmdao.core.petsc_impl import PetscImpl as impl
rank = MPI.COMM_WORLD.rank
else:
from openmdao.api import BasicImpl as impl
rank = 0
class DistribCompSimple(Component):
"""Uses 2 procs but takes full input vars"""
def __init__(self, arr_size=2):
super(DistribCompSimple, self).__init__()
self._arr_size = arr_size
self.add_param('invar', 0.)
self.add_output('outvec', np.ones(arr_size, float))
def solve_nonlinear(self, params, unknowns, resids):
if rank == 0:
unknowns['outvec'] = params['invar'] * np.ones(self._arr_size) * 0.25
elif rank == 1:
unknowns['outvec'] = params['invar'] * np.ones(self._arr_size) * 0.5
print 'hello from rank', rank, unknowns['outvec']
def get_req_procs(self):
return (2, 2)
if __name__ == '__main__':
N_PROCS = 4
prob = Problem(impl=impl)
root = prob.root = Group()
root.add('p1', IndepVarComp('invar', 0.), promotes=['*'])
root.add('comp', DistribCompSimple(2), promotes=['*'])
prob.driver = LatinHypercubeDriver(4, num_par_doe=N_PROCS/2)
prob.driver.add_desvar('invar', lower=-5.0, upper=5.0)
prob.driver.add_objective('outvec')
prob.setup(check=False)
prob.run()
I run this with
mpirun -np 4 python lhc_driver.py
and get this error:
Traceback (most recent call last):
File "lhc_driver.py", line 60, in <module>
prob.run()
File "/Users/frza/git/OpenMDAO/openmdao/core/problem.py", line 1064, in run
self.driver.run(self)
File "/Users/frza/git/OpenMDAO/openmdao/drivers/predeterminedruns_driver.py", line 157, in run
self._run_par_doe(problem.root)
File "/Users/frza/git/OpenMDAO/openmdao/drivers/predeterminedruns_driver.py", line 221, in _run_par_doe
for case in self._get_case_w_nones(self._distrib_build_runlist()):
File "/Users/frza/git/OpenMDAO/openmdao/drivers/predeterminedruns_driver.py", line 283, in _get_case_w_nones
case = next(it)
File "/Users/frza/git/OpenMDAO/openmdao/drivers/latinhypercube_driver.py", line 119, in _distrib_build_runlist
run_list = comm.scatter(job_list, root=0)
File "MPI/Comm.pyx", line 1286, in mpi4py.MPI.Comm.scatter (src/mpi4py.MPI.c:109079)
File "MPI/msgpickle.pxi", line 707, in mpi4py.MPI.PyMPI_scatter (src/mpi4py.MPI.c:48114)
File "MPI/msgpickle.pxi", line 161, in mpi4py.MPI.Pickle.dumpv (src/mpi4py.MPI.c:41605)
ValueError: expecting 4 items, got 2
I don't see a test for this use case in the latest master, so does that mean you don't yet support it or is it a bug?