kedro.runner.ParallelRunner

class kedro.runner.ParallelRunner(max_workers=None, is_async=False)[source]

ParallelRunner is an AbstractRunner implementation. It can be used to run the Pipeline in parallel groups formed by toposort. Please note that this runner implementation validates dataset using the _validate_catalog method, which checks if any of the datasets are single process only using the _SINGLE_PROCESS dataset attribute.

Methods

create_default_data_set(ds_name)

Factory method for creating the default dataset for the runner.

run(pipeline, catalog[, hook_manager, ...])

Run the Pipeline using the datasets provided by catalog and save results back to the same objects.

run_only_missing(pipeline, catalog, hook_manager)

Run only the missing outputs from the Pipeline using the datasets provided by catalog, and save results back to the same objects.
__init__(max_workers=None, is_async=False)[source]

Instantiates the runner by creating a Manager.

Parameters

  • max_workers (Optional[int]) – Number of worker processes to spawn. If not set, calculated automatically based on the pipeline configuration and CPU core count. On windows machines, the max_workers value cannot be larger than 61 and will be set to min(61, max_workers).

  • is_async (bool) – If True, the node inputs and outputs are loaded and saved asynchronously with threads. Defaults to False.

Raises

ValueError – bad parameters passed

create_default_data_set(ds_name)[source]

Factory method for creating the default dataset for the runner.

Parameters

ds_name (str) – Name of the missing dataset.

Return type

_SharedMemoryDataset

Returns

An instance of _SharedMemoryDataset to be used for all unregistered datasets.

run(pipeline, catalog, hook_manager=None, session_id=None)

Run the Pipeline using the datasets provided by catalog and save results back to the same objects.

Parameters

  • pipeline – The Pipeline to run.

  • catalog – The DataCatalog from which to fetch data.

  • hook_manager – The PluginManager to activate hooks.

  • session_id – The id of the session.

Raises

ValueError – Raised when Pipeline inputs cannot be satisfied.

Returns

Any node outputs that cannot be processed by the DataCatalog. These are returned in a dictionary, where the keys are defined by the node outputs.

run_only_missing(pipeline, catalog, hook_manager)

Run only the missing outputs from the Pipeline using the datasets provided by catalog, and save results back to the same objects.

Parameters

  • pipeline – The Pipeline to run.

  • catalog – The DataCatalog from which to fetch data.

  • hook_manager – The PluginManager to activate hooks.

Raises

ValueError – Raised when Pipeline inputs cannot be satisfied.

Returns

Any node outputs that cannot be processed by the DataCatalog. These are returned in a dictionary, where the keys are defined by the node outputs.