I've installed mpi4py and was trying to write my own python code to run across nodes. The demo folder for the MPI for python package had a hello world script that I executed and it ran successfully with the following output:
I've got 2xraspberrypi's (quad cores) and the output came out right!
Command: mpiexec --hostfile machinefile -n 8 python ~/mpi4py/mpi4py-3.0.3/demo/helloworld.py
Output:
Hello, World! I am process 0 of 8 on node001.
Hello, World! I am process 1 of 8 on node001.
Hello, World! I am process 2 of 8 on node001.
Hello, World! I am process 3 of 8 on node001.
Hello, World! I am process 6 of 8 on node002.
Hello, World! I am process 7 of 8 on node002.
Hello, World! I am process 4 of 8 on node002.
Hello, World! I am process 5 of 8 on node002.
I attempted to create a python script and copy-pasted the python script from the demo folder and ran the following command:
Command: mpiexec --hostfile machinefile -n 8 python ~/Desktop/sct/sct.py
But my output was only limited to four prints:
Hello, World! I am process 2 of 8 on node001.
Hello, World! I am process 3 of 8 on node001.
Hello, World! I am process 0 of 8 on node001.
Hello, World! I am process 1 of 8 on node001.
It's the exact same code copy pasted. I don't understand whats going wrong. It should print out 8 times like it did from the demo folder but here it just prints out 4.
In case y'all need the code in the python script its:
#!/usr/bin/env python
"""
Parallel Hello World
"""
from mpi4py import MPI
import sys
size = MPI.COMM_WORLD.Get_size()
rank = MPI.COMM_WORLD.Get_rank()
name = MPI.Get_processor_name()
sys.stdout.write(
"Hello, World! I am process %d of %d on %s.\n"
% (rank, size, name))
Please help!
