"""
The ``mlflow.fastai`` module provides an API for logging and loading fast.ai models. This module
exports fast.ai models with the following flavors:
fastai (native) format
This is the main flavor that can be loaded back into fastai.
:py:mod:`mlflow.pyfunc`
Produced for use by generic pyfunc-based deployment tools and batch inference.
.. _fastai.Learner:
https://docs.fast.ai/basic_train.html#Learner
.. _fastai.Learner.export:
https://docs.fast.ai/basic_train.html#Learner.export
"""
import logging
import os
import tempfile
from pathlib import Path
from typing import Any, Dict, Optional
import numpy as np
import pandas as pd
import yaml
import mlflow.tracking
from mlflow import pyfunc
from mlflow.models import Model, ModelInputExample, ModelSignature
from mlflow.models.model import MLMODEL_FILE_NAME
from mlflow.models.signature import _infer_signature_from_input_example
from mlflow.models.utils import _save_example
from mlflow.tracking._model_registry import DEFAULT_AWAIT_MAX_SLEEP_SECONDS
from mlflow.tracking.artifact_utils import _download_artifact_from_uri
from mlflow.utils.autologging_utils import (
autologging_integration,
batch_metrics_logger,
log_fn_args_as_params,
safe_patch,
)
from mlflow.utils.docstring_utils import LOG_MODEL_PARAM_DOCS, format_docstring
from mlflow.utils.environment import (
_CONDA_ENV_FILE_NAME,
_CONSTRAINTS_FILE_NAME,
_PYTHON_ENV_FILE_NAME,
_REQUIREMENTS_FILE_NAME,
_mlflow_conda_env,
_process_conda_env,
_process_pip_requirements,
_PythonEnv,
_validate_env_arguments,
)
from mlflow.utils.file_utils import get_total_file_size, write_to
from mlflow.utils.model_utils import (
_add_code_from_conf_to_system_path,
_get_flavor_configuration,
_validate_and_copy_code_paths,
_validate_and_prepare_target_save_path,
)
from mlflow.utils.requirements_utils import _get_pinned_requirement
FLAVOR_NAME = "fastai"
_MODEL_DATA_SUBPATH = "model.fastai"
_logger = logging.getLogger(__name__)
[docs]def get_default_pip_requirements(include_cloudpickle=False):
"""
Returns:
A list of default pip requirements for MLflow Models produced by this flavor.
Calls to :func:`save_model()` and :func:`log_model()` produce a pip environment
that, at minimum, contains these requirements.
"""
pip_deps = [_get_pinned_requirement("fastai")]
if include_cloudpickle:
pip_deps.append(_get_pinned_requirement("cloudpickle"))
return pip_deps
[docs]def get_default_conda_env(include_cloudpickle=False):
"""
Returns:
The default Conda environment for MLflow Models produced by calls to
:func:`save_model()` and :func:`log_model()`.
"""
return _mlflow_conda_env(additional_pip_deps=get_default_pip_requirements())
[docs]@format_docstring(LOG_MODEL_PARAM_DOCS.format(package_name=FLAVOR_NAME))
def save_model(
fastai_learner,
path,
conda_env=None,
code_paths=None,
mlflow_model=None,
signature: ModelSignature = None,
input_example: ModelInputExample = None,
pip_requirements=None,
extra_pip_requirements=None,
metadata=None,
**kwargs,
):
"""Save a fastai Learner to a path on the local file system.
Args:
fastai_learner: fastai Learner to be saved.
path: Local path where the model is to be saved.
conda_env: {{ conda_env }}
code_paths: A list of local filesystem paths to Python file dependencies (or directories
containing file dependencies). These files are *prepended* to the system
path when the model is loaded.
mlflow_model: MLflow model config this flavor is being added to.
signature: Describes model input and output Schema. The model signature can be inferred
from datasets with valid model input (e.g. the training dataset with target
column omitted) and valid model output (e.g. model predictions generated on
the training dataset), for example:
.. code-block:: python
from mlflow.models import infer_signature
train = df.drop_column("target_label")
predictions = ... # compute model predictions
signature = infer_signature(train, predictions)
input_example: {{ input_example }}
pip_requirements: {{ pip_requirements }}
extra_pip_requirements: {{ extra_pip_requirements }}
metadata: {{ metadata }}
kwargs: kwargs to pass to ``Learner.save`` method.
.. code-block:: python
:caption: Example
import os
import mlflow.fastai
# Create a fastai Learner model
model = ...
# Start MLflow session and save model to current working directory
with mlflow.start_run():
model.fit(epochs, learning_rate)
mlflow.fastai.save_model(model, "model")
# Load saved model for inference
model_uri = "{}/{}".format(os.getcwd(), "model")
loaded_model = mlflow.fastai.load_model(model_uri)
results = loaded_model.predict(predict_data)
"""
import fastai
from fastai.callback.all import ParamScheduler
_validate_env_arguments(conda_env, pip_requirements, extra_pip_requirements)
path = os.path.abspath(path)
_validate_and_prepare_target_save_path(path)
model_data_subpath = _MODEL_DATA_SUBPATH
model_data_path = os.path.join(path, model_data_subpath)
model_data_path = Path(model_data_path)
code_dir_subpath = _validate_and_copy_code_paths(code_paths, path)
if mlflow_model is None:
mlflow_model = Model()
saved_example = _save_example(mlflow_model, input_example, path)
if signature is None and saved_example is not None:
wrapped_model = _FastaiModelWrapper(fastai_learner)
signature = _infer_signature_from_input_example(saved_example, wrapped_model)
if signature is not None:
mlflow_model.signature = signature
if metadata is not None:
mlflow_model.metadata = metadata
# ParamScheduler currently is not pickable
# hence it is been removed before export and added again after export
cbs = [c for c in fastai_learner.cbs if isinstance(c, ParamScheduler)]
fastai_learner.remove_cbs(cbs)
fastai_learner.export(model_data_path, **kwargs)
fastai_learner.add_cbs(cbs)
pyfunc.add_to_model(
mlflow_model,
loader_module="mlflow.fastai",
data=model_data_subpath,
code=code_dir_subpath,
conda_env=_CONDA_ENV_FILE_NAME,
python_env=_PYTHON_ENV_FILE_NAME,
)
mlflow_model.add_flavor(
FLAVOR_NAME,
fastai_version=fastai.__version__,
data=model_data_subpath,
code=code_dir_subpath,
)
if size := get_total_file_size(path):
mlflow_model.model_size_bytes = size
mlflow_model.save(os.path.join(path, MLMODEL_FILE_NAME))
if conda_env is None:
if pip_requirements is None:
default_reqs = get_default_pip_requirements()
# To ensure `_load_pyfunc` can successfully load the model during the dependency
# inference, `mlflow_model.save` must be called beforehand to save an MLmodel file.
inferred_reqs = mlflow.models.infer_pip_requirements(
path,
FLAVOR_NAME,
fallback=default_reqs,
)
default_reqs = sorted(set(inferred_reqs).union(default_reqs))
else:
default_reqs = None
conda_env, pip_requirements, pip_constraints = _process_pip_requirements(
default_reqs,
pip_requirements,
extra_pip_requirements,
)
else:
conda_env, pip_requirements, pip_constraints = _process_conda_env(conda_env)
with open(os.path.join(path, _CONDA_ENV_FILE_NAME), "w") as f:
yaml.safe_dump(conda_env, stream=f, default_flow_style=False)
# Save `constraints.txt` if necessary
if pip_constraints:
write_to(os.path.join(path, _CONSTRAINTS_FILE_NAME), "\n".join(pip_constraints))
# Save `requirements.txt`
write_to(os.path.join(path, _REQUIREMENTS_FILE_NAME), "\n".join(pip_requirements))
_PythonEnv.current().to_yaml(os.path.join(path, _PYTHON_ENV_FILE_NAME))
[docs]@format_docstring(LOG_MODEL_PARAM_DOCS.format(package_name=FLAVOR_NAME))
def log_model(
fastai_learner,
artifact_path,
conda_env=None,
code_paths=None,
registered_model_name=None,
signature: ModelSignature = None,
input_example: ModelInputExample = None,
await_registration_for=DEFAULT_AWAIT_MAX_SLEEP_SECONDS,
pip_requirements=None,
extra_pip_requirements=None,
metadata=None,
**kwargs,
):
"""Log a fastai model as an MLflow artifact for the current run.
Args:
fastai_learner: Fastai model (an instance of `fastai.Learner`_) to be saved.
artifact_path: Run-relative artifact path.
conda_env: {{ conda_env }}
code_paths: A list of local filesystem paths to Python file dependencies (or directories
containing file dependencies). These files are *prepended* to the system
path when the model is loaded.
registered_model_name: This argument may change or be removed in a
future release without warning. If given, create a model
version under ``registered_model_name``, also creating a
registered model if one with the given name does not exist.
signature: Describes model input and output Schema. The model signature can be inferred
from datasets with valid model input (e.g. the training dataset with target
column omitted) and valid model output (e.g. model predictions generated on
the training dataset), for example:
.. code-block:: python
from mlflow.models import infer_signature
train = df.drop_column("target_label")
predictions = ... # compute model predictions
signature = infer_signature(train, predictions)
input_example: {{ input_example }}
kwargs: kwargs to pass to `fastai.Learner.export`_ method.
await_registration_for: Number of seconds to wait for the model version to finish
being created and is in ``READY`` status. By default, the function
waits for five minutes. Specify 0 or None to skip waiting.
pip_requirements: {{ pip_requirements }}
extra_pip_requirements: {{ extra_pip_requirements }}
metadata: {{ metadata }}
Returns:
A ModelInfo instance that contains the metadata of the logged model.
.. code-block:: python
:caption: Example
import fastai.vision as vis
import mlflow.fastai
from mlflow import MlflowClient
def main(epochs=5, learning_rate=0.01):
# Download and untar the MNIST data set
path = vis.untar_data(vis.URLs.MNIST_SAMPLE)
# Prepare, transform, and normalize the data
data = vis.ImageDataBunch.from_folder(
path, ds_tfms=(vis.rand_pad(2, 28), []), bs=64
)
data.normalize(vis.imagenet_stats)
# Create the CNN Learner model
model = vis.cnn_learner(data, vis.models.resnet18, metrics=vis.accuracy)
# Start MLflow session and log model
with mlflow.start_run() as run:
model.fit(epochs, learning_rate)
mlflow.fastai.log_model(model, "model")
# fetch the logged model artifacts
artifacts = [
f.path for f in MlflowClient().list_artifacts(run.info.run_id, "model")
]
print(f"artifacts: {artifacts}")
main()
.. code-block:: text
:caption: Output
artifacts: ['model/MLmodel', 'model/conda.yaml', 'model/model.fastai']
"""
return Model.log(
artifact_path=artifact_path,
flavor=mlflow.fastai,
registered_model_name=registered_model_name,
fastai_learner=fastai_learner,
conda_env=conda_env,
code_paths=code_paths,
signature=signature,
input_example=input_example,
await_registration_for=await_registration_for,
pip_requirements=pip_requirements,
extra_pip_requirements=extra_pip_requirements,
metadata=metadata,
**kwargs,
)
def _load_model(path):
from fastai.learner import load_learner
return load_learner(os.path.abspath(path))
class _FastaiModelWrapper:
def __init__(self, learner):
self.learner = learner
def get_raw_model(self):
"""
Returns the underlying model.
"""
return self.learner
def predict(
self,
dataframe,
params: Optional[Dict[str, Any]] = None,
):
"""
Args:
dataframe: Model input data.
params: Additional parameters to pass to the model for inference.
Returns:
Model predictions.
"""
dl = self.learner.dls.test_dl(dataframe)
preds, _ = self.learner.get_preds(dl=dl)
return pd.Series(map(np.array, preds.numpy())).to_frame("predictions")
def _load_pyfunc(path):
"""Load PyFunc implementation. Called by ``pyfunc.load_model``.
Args:
path: Local filesystem path to the MLflow Model with the ``fastai`` flavor.
"""
return _FastaiModelWrapper(_load_model(path))
[docs]def load_model(model_uri, dst_path=None):
"""Load a fastai model from a local file or a run.
Args:
model_uri: The location, in URI format, of the MLflow model. For example:
- ``/Users/me/path/to/local/model``
- ``relative/path/to/local/model``
- ``s3://my_bucket/path/to/model``
- ``runs:/<mlflow_run_id>/run-relative/path/to/model``
For more information about supported URI schemes, see
`Referencing Artifacts <https://www.mlflow.org/docs/latest/tracking.html#
artifact-locations>`_.
dst_path: The local filesystem path to which to download the model artifact.
This directory must already exist. If unspecified, a local output
path will be created.
Returns:
A fastai model (an instance of `fastai.Learner`_).
.. code-block:: python
:caption: Example
import mlflow.fastai
# Define the Learner model
model = ...
# log the fastai Leaner model
with mlflow.start_run() as run:
model.fit(epochs, learning_rate)
mlflow.fastai.log_model(model, "model")
# Load the model for scoring
model_uri = f"runs:/{run.info.run_id}/model"
loaded_model = mlflow.fastai.load_model(model_uri)
results = loaded_model.predict(predict_data)
"""
local_model_path = _download_artifact_from_uri(artifact_uri=model_uri, output_path=dst_path)
flavor_conf = _get_flavor_configuration(model_path=local_model_path, flavor_name=FLAVOR_NAME)
_add_code_from_conf_to_system_path(local_model_path, flavor_conf)
model_file_path = os.path.join(local_model_path, flavor_conf.get("data", "model.fastai"))
return _load_model(path=model_file_path)
[docs]@autologging_integration(FLAVOR_NAME)
def autolog(
log_models=True,
log_datasets=True,
disable=False,
exclusive=False,
disable_for_unsupported_versions=False,
silent=False,
registered_model_name=None,
extra_tags=None,
):
"""
Enable automatic logging from Fastai to MLflow.
Logs loss and any other metrics specified in the fit function, and optimizer data as parameters.
Model checkpoints are logged as artifacts to a 'models' directory.
MLflow will also log the parameters of the
`EarlyStoppingCallback <https://docs.fast.ai/callback.tracker.html#EarlyStoppingCallback>`_
and `OneCycleScheduler <https://docs.fast.ai/callback.schedule.html#ParamScheduler>`_ callbacks
Args:
log_models: If ``True``, trained models are logged as MLflow model artifacts. If ``False``,
trained models are not logged.
log_datasets: If ``True``, dataset information is logged to MLflow Tracking. If ``False``,
dataset information is not logged.
disable: If ``True``, disables the Fastai autologging integration. If ``False``, enables
the Fastai autologging integration.
exclusive: If ``True``, autologged content is not logged to user-created fluent runs. If
``False``, autologged content is logged to the active fluent run, which may
be user-created.
disable_for_unsupported_versions: If ``True``, disable autologging for versions of fastai
that have not been tested against this version of the MLflow client or are
incompatible.
silent: If ``True``, suppress all event logs and warnings from MLflow during Fastai
autologging. If ``False``, show all events and warnings during Fastai autologging.
registered_model_name: If given, each time a model is trained, it is registered as a new
model version of the registered model with this name. The registered model is created
if it does not already exist.
extra_tags: A dictionary of extra tags to set on each managed run created by
autologging.
.. code-block:: python
:caption: Example
# This is a modified example from
# https://github.com/mlflow/mlflow/tree/master/examples/fastai
# demonstrating autolog capabilities.
import fastai.vision as vis
import mlflow.fastai
from mlflow import MlflowClient
def print_auto_logged_info(r):
tags = {k: v for k, v in r.data.tags.items() if not k.startswith("mlflow.")}
artifacts = [f.path for f in MlflowClient().list_artifacts(r.info.run_id, "model")]
print(f"run_id: {r.info.run_id}")
print(f"artifacts: {artifacts}")
print(f"params: {r.data.params}")
print(f"metrics: {r.data.metrics}")
print(f"tags: {tags}")
def main(epochs=5, learning_rate=0.01):
# Download and untar the MNIST data set
path = vis.untar_data(vis.URLs.MNIST_SAMPLE)
# Prepare, transform, and normalize the data
data = vis.ImageDataBunch.from_folder(
path, ds_tfms=(vis.rand_pad(2, 28), []), bs=64
)
data.normalize(vis.imagenet_stats)
# Create CNN the Learner model
model = vis.cnn_learner(data, vis.models.resnet18, metrics=vis.accuracy)
# Enable auto logging
mlflow.fastai.autolog()
# Start MLflow session
with mlflow.start_run() as run:
model.fit(epochs, learning_rate)
# fetch the auto logged parameters, metrics, and artifacts
print_auto_logged_info(mlflow.get_run(run_id=run.info.run_id))
main()
.. code-block:: text
:caption: output
run_id: 5a23dcbcaa334637814dbce7a00b2f6a
artifacts: ['model/MLmodel', 'model/conda.yaml', 'model/model.fastai']
params: {'wd': 'None',
'bn_wd': 'True',
'opt_func': 'Adam',
'epochs': '5', '
train_bn': 'True',
'num_layers': '60',
'lr': '0.01',
'true_wd': 'True'}
metrics: {'train_loss': 0.024,
'accuracy': 0.99214,
'valid_loss': 0.021}
# Tags model summary omitted too long
tags: {...}
.. figure:: ../_static/images/fastai_autolog.png
Fastai autologged MLflow entities
"""
from fastai.callback.all import EarlyStoppingCallback, TrackerCallback
from fastai.callback.hook import _print_shapes, find_bs, layer_info, module_summary
from fastai.learner import Learner
def getFastaiCallback(metrics_logger, is_fine_tune=False):
from mlflow.fastai.callback import __MlflowFastaiCallback
return __MlflowFastaiCallback(
metrics_logger=metrics_logger,
log_models=log_models,
is_fine_tune=is_fine_tune,
)
def _find_callback_of_type(callback_type, callbacks):
for callback in callbacks:
if isinstance(callback, callback_type):
return callback
return None
def _log_early_stop_callback_params(callback):
if callback:
try:
earlystopping_params = {
"early_stop_monitor": callback.monitor,
"early_stop_min_delta": callback.min_delta,
"early_stop_patience": callback.patience,
"early_stop_comp": callback.comp.__name__,
}
mlflow.log_params(earlystopping_params)
except Exception:
return
def _log_model_info(learner):
# The process executed here, are incompatible with TrackerCallback
# Hence it is removed and add again after the execution
remove_cbs = [cb for cb in learner.cbs if isinstance(cb, TrackerCallback)]
if remove_cbs:
learner.remove_cbs(remove_cbs)
xb = learner.dls.train.one_batch()[: learner.dls.train.n_inp]
infos = layer_info(learner, *xb)
bs = find_bs(xb)
inp_sz = _print_shapes((x.shape for x in xb), bs)
mlflow.log_param("input_size", inp_sz)
mlflow.log_param("num_layers", len(infos))
summary = module_summary(learner, *xb)
# Add again TrackerCallback
if remove_cbs:
learner.add_cbs(remove_cbs)
with tempfile.TemporaryDirectory() as tempdir:
summary_file = os.path.join(tempdir, "module_summary.txt")
with open(summary_file, "w") as f:
f.write(summary)
mlflow.log_artifact(local_path=summary_file)
def _run_and_log_function(self, original, args, kwargs, unlogged_params, is_fine_tune=False):
# Check if is trying to fit while fine tuning or not
mlflow_cbs = [cb for cb in self.cbs if cb.name == "___mlflow_fastai"]
fit_in_fine_tune = (
original.__name__ == "fit" and len(mlflow_cbs) > 0 and mlflow_cbs[0].is_fine_tune
)
if not fit_in_fine_tune:
log_fn_args_as_params(original, list(args), kwargs, unlogged_params)
run_id = mlflow.active_run().info.run_id
with batch_metrics_logger(run_id) as metrics_logger:
if not fit_in_fine_tune:
early_stop_callback = _find_callback_of_type(EarlyStoppingCallback, self.cbs)
_log_early_stop_callback_params(early_stop_callback)
# First try to remove if any already registered callback
self.remove_cbs(mlflow_cbs)
# Log information regarding model and data without bar and print-out
with self.no_bar(), self.no_logging():
_log_model_info(learner=self)
mlflowFastaiCallback = getFastaiCallback(
metrics_logger=metrics_logger, is_fine_tune=is_fine_tune
)
# Add the new callback
self.add_cb(mlflowFastaiCallback)
return original(self, *args, **kwargs)
def fit(original, self, *args, **kwargs):
unlogged_params = ["self", "cbs", "learner", "lr", "lr_max", "wd"]
return _run_and_log_function(
self, original, args, kwargs, unlogged_params, is_fine_tune=False
)
safe_patch(FLAVOR_NAME, Learner, "fit", fit, manage_run=True, extra_tags=extra_tags)
def fine_tune(original, self, *args, **kwargs):
unlogged_params = ["self", "cbs", "learner", "lr", "lr_max", "wd"]
return _run_and_log_function(
self, original, args, kwargs, unlogged_params, is_fine_tune=True
)
safe_patch(FLAVOR_NAME, Learner, "fine_tune", fine_tune, manage_run=True, extra_tags=extra_tags)