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Artifacts & Models

ClearML allows easy storage of experiments' output products as artifacts that can later be accessed easily and used, through the web UI or programmatically.

A few examples of artifacts are:

  • Model snapshot / weights file
  • Data preprocessing
  • Feature representation of data
  • and more!


Logging Artifacts#

To log any type of artifact to a Task, use the upload_artifact() method. For example:

  • Upload a local file containing the preprocessing results of the data.
task.upload_artifact(name='data', artifact_object='/path/to/preprocess_data.csv')
  • Upload an entire folder with all its content by passing the folder, which will be zipped and uploaded as a single zip file:
task.upload_artifact(name='folder', artifact_object='/path/to/folder/')
  • Upload an instance of an object, Numpy / Pandas / PIL (converted to npz / csv.gz / jpg formats accordingly). If the object type is unknown, it is pickled and uploaded.
person_dict = {'name': 'Erik', 'age': 30}
task.upload_artifact(name='person dictionary', artifact_object=person_dict)

See more details in the artifacts example.

Using Artifacts#

To access a Task's artifact in order to use it:

  1. Get the Task that created the artifact (see more details on querying Tasks).

  2. Retrieve all the Task's artifacts with the artifact property, which is essentially a dictionary, where the key is the artifact name, and the value is the artifact itself.

  3. Access a specific artifact using one of the following methods:

    • Access files by calling get_local_copy(), which caches the files for later use and returns a path to the cached file
    • Access object artifacts by using the get() method that returns the Python object.

The code below demonstrates how to access a file artifact using the previously generated preprocessed data:

# get instance of Task that created artifact, using Task ID
preprocess_task = Task.get_task(task_id='the_preprocessing_task_id')
# access artifact
local_csv = preprocess_task.artifacts['data'].get_local_copy()

See more details in the using artifacts example.

List of Supported Artifacts#

  • Numpy array (as npz file)
  • Pandas dataframe
  • PIL (converted to jpg)
  • Files and folders
  • Python objects (pickled)


Models are a special kind of artifact and, unlike regular artifacts, which can only be accessed with the creating Task's ID, Models are entities with their own unique ID that can be accessed directly or via the creating task.

This property makes Models a standalone entry that can be used as an artifactory interface.

Automatic Model Logging#

When models are saved using certain frameworks (for instance, by calling the method), ClearML automatically logs the models and all snapshot paths.


See model storage examples, TF, PyTorch, Keras, Scikit-Learn.

Manual Model Logging#

To manually log a model, create an instance of OutputModel class:

from clearml import OutputModel, Task
# Instantiate a Task
task = Task.init(project_name="myProject", task_name="myTask")
# Instantiate an OutputModel, with a Task object argument
output_model = OutputModel(task=task, framework="PyTorch")

The OutputModel object is always connected to a Task object as it's instantiated with a Task object as an argument. It is, therefore, automatically registered as the Task’s output model.

The snapshots of manually uploaded models aren't automatically captured, but there are two methods to update an output model.

Updating Via Task Object#

Using the Task.update_output_model method:


It's possible to modify the following parameters:

  • Weights file / folder - Uploads the files specified with the model_path. If a remote storage is provided (S3 / GS / Https etc...), it saves the URL.
  • Model Metadata - Model name, description, iteration number of model, and tags.

Updating Via Model Object#

Using the OutputModel.update_weights method:

  • Specify either the name of a locally stored weights file to upload (weights_filename), or the URI of a storage destination for model weight upload (registered_uri).
  • Model Metadata - Model description and iteration number.

Using Models#

Loading a previously trained model is quite similar to loading artifacts.

prev_task = Task.get_task(task_id='the_training_task')
last_snapshot = prev_task.models['output'][-1]
local_weights_path = last_snapshot.get_local_copy()
  1. Get the instance of the Task that created the original weights files
  2. Query the Task on its output models (a list of snapshots)
  3. Get the latest snapshot (if using Tensorflow, the snapshots are stored in a folder, so the local_weights_path will point to a folder containing the requested snapshot).

Notice that if one of the frameworks will load the weights file, the running Task will automatically update, with "Input Model" pointing directly to the original training Task's model. With this feature, it's easy to get a full genealogy of every trained and used model in our system!

Loading framework models appear under the "Input Models" section, under the Artifacts tab in the ClearML UI.

Setting Upload Destination#

ClearML automatically captures the storage path of Models created by frameworks such as TF, Pytorch, and scikit-learn. By default, it stores the local loading path they are saved to.

To automatically store all created models by a specific experiment, modify the Task.init() function as such:

task = Task.init(project_name='examples', task_name='storing model', output_uri='s3://my_models/')

To automatically store all created models from all experiments in a certain storage medium, edit the clearml.conf (see ClearML Configuration Reference) and set sdk.developmenmt.default_output_uri to the desired storage (see Storage). This is especially helpful when using clearml-agent to execute code.

List of Supported Frameworks#

  • Tensorflow
  • Keras
  • Pytorch
  • scikit-learn (only using joblib)
  • XGBoost (only using joblib)