Parallelism - using multiple cores#
Often you will want to evaluate the function on some remote computing resources.
adaptive works out of the box with any framework that implements a PEP 3148 compliant executor that returns
from concurrent.futures import ProcessPoolExecutor executor = ProcessPoolExecutor(max_workers=4) learner = adaptive.Learner1D(f, bounds=(-1, 1)) runner = adaptive.Runner(learner, executor=executor, loss_goal=0.05) runner.live_info() runner.live_plot(update_interval=0.1)
import ipyparallel client = ipyparallel.Client() # You will need to start an `ipcluster` to make this work learner = adaptive.Learner1D(f, bounds=(-1, 1)) runner = adaptive.Runner(learner, executor=client, loss_goal=0.01) runner.live_info() runner.live_plot()
On Windows by default
adaptive.Runner uses a
import distributed client = distributed.Client() learner = adaptive.Learner1D(f, bounds=(-1, 1)) runner = adaptive.Runner(learner, executor=client, loss_goal=0.01) runner.live_info() runner.live_plot(update_interval=0.1)
This makes sense if you want to run a
Learner on a cluster non-interactively using a job script.
For example, you create the following file called
from mpi4py.futures import MPIPoolExecutor # use the idiom below, see the warning at # https://mpi4py.readthedocs.io/en/stable/mpi4py.futures.html#mpipoolexecutor if __name__ == "__main__": learner = adaptive.Learner1D(f, bounds=(-1, 1)) # load the data learner.load(fname) # run until `goal` is reached with an `MPIPoolExecutor` runner = adaptive.Runner( learner, executor=MPIPoolExecutor(), shutdown_executor=True, loss_goal=0.01, ) # periodically save the data (in case the job dies) runner.start_periodic_saving(dict(fname=fname), interval=600) # block until runner goal reached runner.ioloop.run_until_complete(runner.task) # save one final time before exiting learner.save(fname)
On your laptop/desktop you can run this script like:
export MPI4PY_MAX_WORKERS=15 mpiexec -n 1 python run_learner.py
Or you can pass
max_workers=15 programmatically when creating the
Inside the job script using a job queuing system use:
mpiexec -n 16 python -m mpi4py.futures run_learner.py
How you call MPI might depend on your specific queuing system, with SLURM for example it’s:
#!/bin/bash #SBATCH --job-name adaptive-example #SBATCH --ntasks 100 srun -n $SLURM_NTASKS --mpi=pmi2 ~/miniconda3/envs/py37_min/bin/python -m mpi4py.futures run_learner.py
This executor is basically a powered-up version of
ProcessPoolExecutor, check its documentation.
Among other things, it allows to reuse the executor and uses
cloudpickle for serialization.
This means you can even learn closures, lambdas, or other functions that are not picklable with
from loky import get_reusable_executor ex = get_reusable_executor() f = lambda x: x learner = adaptive.Learner1D(f, bounds=(-1, 1)) runner = adaptive.Runner(learner, loss_goal=0.01, executor=ex) runner.live_info()