Error Messages

This section lists descriptions and background for common error messages and warnings raised or emitted by Optuna Dashboard.

Warning Messages

Human-in-the-loop optimization will not work with _CachedStorage in Optuna prior to v3.2.

This warning occurs when the storage object associated with the Optuna Study is of the _CachedStorage class.

When using RDBStorage with Optuna, it is implicitly wrapped with the _CachedStorage class for performance improvement. However, there is a bug in the _CachedStorage class that prevents Optuna from synchronizing the latest Trial information. This bug is not a problem for the general use case of Optuna, but it is critical for human-in-the-loop optimization.

If you are using a version prior to v3.2, please upgrade to v3.2 or later, use another storage classes, or use a following dirty hack to unwrap _CachedStorage class.

if isinstance(study._storage, optuna.storages._CachedStorage):
    study._storage = study._storage._backend

set_objective_names() function is deprecated. Please use study.set_metric_names() instead.

set_objective_names() function has been ported to Optuna. Please use study.set_metric_names() function instead.

Deprecated APIs	Corresponding Active APIs
optuna_dashboard.set_objective_names(study, ["objective 1", "objective 2"])	study.set_metric_names(["objective 1", "objective 2"])

upload_artifact() is deprecated. Please use optuna.artifacts.upload_artifact() instead.

upload_artifact() function has been ported to Optuna. Please use optuna.artifacts.upload_artifact function instead.

Deprecated APIs	Corresponding Active APIs
optuna_dashboard.artifact.upload_artifact(artifact_backend, trial, fiel_path)	optuna.artifacts.upload_artifact(trial, file_path, artifact_store)

Please note that the order of arguments is different between the deprecated and active APIs.

FileSystemBackend is deprecated. Please use FileSystemArtifactStore instead.

FileSystemBackend class has been ported to Optuna. Please use FileSystemArtifactStore class instead.

Deprecated APIs	Corresponding Active APIs
optuna_dashboard.artifact.file_system.FileSystemBackend(base_path)	optuna.artifacts.FileSystemArtifactStore(base_path)

Boto3Backend` is deprecated. Please use Boto3ArtifactStore instead.

Boto3Backend class has been ported to Optuna. Please use Boto3ArtifactStore class instead.

Deprecated APIs	Corresponding Active APIs
optuna_dashboard.artifact.boto3.Boto3Backend(bucket_name, client=None)	optuna.artifacts.Boto3ArtifactStore(bucket_name, client=None)