running.md

Running Grappa programs

Grappa jobs are run like any other MPI job. This process varies depending on how your cluster is configured and what version of MPI you use. The Grappa team primarily works on machines that use the Slurm scheduler, and thus we have built a tools to make it easy to run Grappa programs under Slurm. However, it is not necessary to use these tools to run Grappa jobs---as long as you make sure the right environment variables are set, any MPI job launcher will work.

Using Slurm and grappa_srun

The Ruby script bin/grappa_srun can be used to automatically manage the pesky srun flags and GASNET settings that are needed to run Grappa programs correctly on a number of machines that we've tested on. Try running bin/grappa_srun --help for more detailed usage information.

Running an application:

# in build/Make+Release: #
# build the desired executable #
make -j graph_new.exe
# launch a Slurm job to run it: #
bin/grappa_srun --nnode=2 --ppn=2 -- graph_new.exe --scale=26 --bench=bfs --nbfs=8 --num_starting_workers=512

Running a Grappa test:

# in your configured directory, (e.g. build/Make+Release) #
# (builds and runs the test) #
make -j check-New_delegate_tests
# or in two steps: #
make -j New_delegate_tests.test
bin/grappa_srun --nnode=2 --ppn=2 --test=New_delegate_tests

Using another MPI job launcher

You may use whatever mechanism you normally do to launch MPI jobs, but make sure you set the appropriate environment variables. Take a look at bin/srun_prolog and bin/srun_epilog to see what we do for Slurm.