ray.data.read_datasource#

ray.data.read_datasource(datasource: Datasource, *, parallelism: int = -1, ray_remote_args: Dict[str, Any] = None, concurrency: int | None = None, override_num_blocks: int | None = None, **read_args) → Dataset[source]#

Read a stream from a custom Datasource.

Parameters:

  • datasource – The Datasource to read data from.

  • parallelism – This argument is deprecated. Use override_num_blocks argument.

  • ray_remote_args – kwargs passed to ray.remote() in the read tasks.

  • concurrency – The maximum number of Ray tasks to run concurrently. Set this to control number of tasks to run concurrently. This doesn’t change the total number of tasks run or the total number of output blocks. By default, concurrency is dynamically decided based on the available resources.

  • override_num_blocks – Override the number of output blocks from all read tasks. By default, the number of output blocks is dynamically decided based on input data size and available resources. You shouldn’t manually set this value in most cases.

  • read_args – Additional kwargs to pass to the Datasource implementation.

Returns:

Dataset that reads data from the Datasource.