Modin engines

As a rule, you don't have to worry about initialization of an execution engine as Modin itself automatically initializes one when performing the first operation. Also, Modin has a broad range of :doc:configuration settings </flow/modin/config>, which you can use to configure an execution engine. If there is a reason to initialize an execution engine on your own and you are sure what to do, Modin will automatically attach to whichever engine is available. Below, you can find some examples on how to initialize a specific execution engine on your own.

Ray

You can initialize Ray engine with a specific number of CPUs (worker processes) to perform computation.

.. code-block:: python

import ray import modin.config as modin_cfg

ray.init(num_cpus=<N>) modin_cfg.Engine.put("ray") # Modin will use Ray engine modin_cfg.CpuCount.put(<N>)

To get more details on all possible parameters for initialization refer to Ray documentation_.

Dask

You can initialize Dask engine with a specific number of worker processes and threads per worker to perform computation.

.. code-block:: python

from distributed import Client import modin.config as modin_cfg

client = Client(n_workers=<N1>, threads_per_worker=<N2>) modin_cfg.Engine.put("dask") # # Modin will use Dask engine modin_cfg.CpuCount.put(<N1>)

To get more details on all possible parameters for initialization refer to Dask Distributed documentation_.

MPI through unidist

You can initialize MPI through unidist engine with a specific number of CPUs (worker processes) to perform computation.

.. code-block:: python

import unidist import unidist.config as unidist_cfg import modin.config as modin_cfg

unidist_cfg.Backend.put("mpi") unidist_cfg.CpuCount.put(<N>) unidist.init()

modin_cfg.Engine.put("unidist") # # Modin will use MPI through unidist engine modin_cfg.CpuCount.put(<N>)

To get more details on all possible parameters for initialization refer to unidist documentation_.

.. _Ray documentation: https://docs.ray.io/en/latest .. _Dask Distributed documentation: https://distributed.dask.org/en/latest .. _unidist documentation: https://unidist.readthedocs.io/en/latest