[BUG] referencing models by stage using models URI suddenly became case sensitive

[lichenran1234]

Willingness to contribute

The MLflow Community encourages bug fix contributions. Would you or another member of your organization be willing to contribute a fix for this bug to the MLflow code base?

• Yes. I can contribute a fix for this bug independently.
• Yes. I would be willing to contribute a fix for this bug with guidance from the MLflow community.
• No. I cannot contribute a bug fix at this time.

Describe the problem

Mlflow model registry allows users to load models using models URI. One format of the models URI is models:/<model_name>/<stage>, for example, models:/regressor/Production.

Model registry has been accepting case insensitive model URIs, like models:/regressor/production, in mlflow < 1.23.0.

But after the bug introduced in mlflow 1.23.0 (by PR #5027), referencing models by stage suddenly became case sensitive. To reference the latest Production version of model regressor, only this format is working:

• models:/regressor/Production

These formats are no longer working:

• models:/regressor/production
• models:/regressor/pRoduction

What component(s), interfaces, languages, and integrations does this bug affect?

Components

• area/artifacts: Artifact stores and artifact logging
• area/build: Build and test infrastructure for MLflow
• area/docs: MLflow documentation pages
• area/examples: Example code
• area/model-registry: Model Registry service, APIs, and the fluent client calls for Model Registry
• area/models: MLmodel format, model serialization/deserialization, flavors
• area/projects: MLproject format, project running backends
• area/scoring: MLflow Model server, model deployment tools, Spark UDFs
• area/server-infra: MLflow Tracking server backend
• area/tracking: Tracking Service, tracking client APIs, autologging

Interface

• area/uiux: Front-end, user experience, plotting, JavaScript, JavaScript dev server
• area/docker: Docker use across MLflow's components, such as MLflow Projects and MLflow Models
• area/sqlalchemy: Use of SQLAlchemy in the Tracking Service or Model Registry
• area/windows: Windows support

Language

• language/r: R APIs and clients
• language/java: Java APIs and clients
• language/new: Proposals for new client languages

Integrations

• integrations/azure: Azure and Azure ML integrations
• integrations/sagemaker: SageMaker integrations
• integrations/databricks: Databricks integrations

[lichenran1234]

I'm working on a PR to fix this issue.