Files
2026-07-13 13:17:40 +08:00

87 lines
2.6 KiB
ReStructuredText

Configure scale and GPUs
------------------------
Outside of your training function, create a :class:`~ray.train.ScalingConfig` object to configure:
1. :class:`num_workers <ray.train.ScalingConfig>` - The number of distributed training worker processes.
2. :class:`use_gpu <ray.train.ScalingConfig>` - Whether each worker should use a GPU (or CPU).
.. testcode::
from ray.train import ScalingConfig
scaling_config = ScalingConfig(num_workers=2, use_gpu=True)
For more details, see :ref:`train_scaling_config`.
Configure persistent storage
----------------------------
Create a :class:`~ray.train.RunConfig` object to specify the path where results
(including checkpoints and artifacts) will be saved.
.. testcode::
from ray.train import RunConfig
# Local path (/some/local/path/unique_run_name)
run_config = RunConfig(storage_path="/some/local/path", name="unique_run_name")
# Shared cloud storage URI (s3://bucket/unique_run_name)
run_config = RunConfig(storage_path="s3://bucket", name="unique_run_name")
# Shared NFS path (/mnt/nfs/unique_run_name)
run_config = RunConfig(storage_path="/mnt/nfs", name="unique_run_name")
.. warning::
Specifying a *shared storage location* (such as cloud storage or NFS) is
*optional* for single-node clusters, but it is **required for multi-node clusters.**
Using a local path will :ref:`raise an error <multinode-local-storage-warning>`
during checkpointing for multi-node clusters.
For more details, see :ref:`persistent-storage-guide`.
Launch a training job
---------------------
Tying this all together, you can now launch a distributed training job
with a :class:`~ray.train.torch.TorchTrainer`.
.. testcode::
:hide:
from ray.train import ScalingConfig
train_func = lambda: None
scaling_config = ScalingConfig(num_workers=1)
run_config = None
.. testcode::
from ray.train.torch import TorchTrainer
trainer = TorchTrainer(
train_func, scaling_config=scaling_config, run_config=run_config
)
result = trainer.fit()
Access training results
-----------------------
After training completes, a :class:`~ray.train.Result` object is returned which contains
information about the training run, including the metrics and checkpoints reported during training.
.. testcode::
result.metrics # The metrics reported during training.
result.checkpoint # The latest checkpoint reported during training.
result.path # The path where logs are stored.
result.error # The exception that was raised, if training failed.
For more usage examples, see :ref:`train-inspect-results`.