Install mpi4py & mpich2
conda install mpi4py
Try out examples
mpirun -n 4 script_file.py
See also: https://github.com/rosafilgueira/mpi4py_examples
These programs depend on mpi4py (>= Version 1.0)
The mpi4py documentation and installation instructions can be found at:
Run it with
mpirun -n 4 ./some-program
where the number after "-n" is the numer of parallel MPI processes to be started.
If you want to run the program distributed over multiple hosts, you have to create a which looks like:
-- hostfile --
host1 slots=4
host2 slots=4
host3 slots=4
Where "slots=" specifies the number of parallel processes that should be started on that host.
Run it with
mpirun --hostfile <hostfile> ./some-program
There are two possibilities:
a) Run interactively:
Request an interactive session and allocate a number of processors/nodes for your session:
$ qsub -I X -l nodes=4:ppn=4
Where "-I" means you want to work interactively, "-X" requests grapical (X-Window) I/O -- (you can run arbitrary programs that open windows). The option "-l " specifies the resources you want to allocate. "-l nodes=4:ppn=4" requests four compute nodes with each having four processor cores [ppn =^ ProcessorsPerNode]. So in total you allocate 16 CPU cores. [The scheduler is free to run your job on two nodes having 8 CPU cores each]
Once your interactive session is ready, run
$ mpirun ./your-program
mpirun automatically knowns how many parallel processes have to be started and where they have to be started.
b) Submit as non-interactive batch-job:
Use $ qsub -l nodes=4:ppn=4 ./your-jobfile.job
to submit jour job-file. Similar to the interactive case, "-l" again is used to request resources from the scheduling system. The job file usually is a simple shell script which specifies the commands to be run once your job starts. In addition, the jobfile can contain "#PBS " statements which are used to specify additional options which could have been specified in the "qsub" commandline. Please see "man qsub" for details.