lenskit.config.ParallelSettings
===============================

.. py:class:: lenskit.config.ParallelSettings
   :canonical: lenskit.config._schema.ParallelSettings

   Bases: :py:obj:`pydantic_settings.BaseSettings`


   Configuration for LensKit's parallel processing.  These settings are in the
   ``[parallel]`` table in ``lenskit.toml``.

   .. seealso::
       :ref:`parallel-config`


   .. py:attribute:: model_config


   .. py:attribute:: num_cpus
      :type:  int
      :value: 0


      The number of CPUs LensKit should consider using.  This is auto-detected
      from the system environment, and should only be configured manually if you
      want to override LensKit's CPU detection for some reason.  Note that the
      auto-detected values *do* account for operating system scheduling affinities
      and CPU limits.

      This value is not used directly as a limit, but is used to derive the
      default values for the other concurrency controls (threads, etc.).


   .. py:attribute:: use_ray
      :type:  bool
      :value: False


      Use Ray to parallelize batch operations, hyperparameter tuning, etc.


   .. py:attribute:: num_batch_jobs
      :type:  int
      :value: 0


      Number of batch inference jobs to run in parallel.  Can be overridden with
      the :envvar:`LK_NUM_BATCH_JOBS` environment variable.


   .. py:attribute:: num_procs
      :type:  int
      :value: 0


      Number of processes to use.


   .. py:attribute:: num_threads
      :type:  int
      :value: 0


      Number of threads to use.  Can be overridden with the
      :envvar:`LK_NUM_THREADS` environment variable.  Specify -1 to use all
      available threads.


   .. py:attribute:: num_backend_threads
      :type:  int
      :value: 0


      Number of threads for compute backends to use.  Can be overridden with the
      :envvar:`LK_NUM_BACKEND_THREADS` environment variable.  Specify -1 to leave
      threading limits unmodified.


   .. py:property:: total_threads


   .. py:method:: resolve_defaults()

      Resolve default values for thread/process counts.



   .. py:method:: env_vars()

      Get the parallel configuration as a set of environment variables to
      configure a child process.  The set also includes ``OMP_NUM_THREADS``
      and related variables for BLAS and MKL to configure OMP early.