Purpose

This topic describes the challenges and solutions that models address.

Challenge

Data scientists often develop models using a variety of Python/R open source packages. The challenge lies in actually exposing those models to stakeholders who can test the model. In most organizations, the model deployment process will require assistance from a separate DevOps team who likely have their own policies about deploying new code.

For example, a model that has been developed in Python by data scientists might be rebuilt in another language by the devops team before it is actually deployed. This process can be slow and error-prone. It can take months to deploy new models, if at all. This also introduces compliance risks when you take into account the fact that the new re-developed model might not be even be an accurate reproduction of the original model.

Once a model has been deployed, you then need to ensure that the devops team has a way to rollback the model to a previous version if needed. This means the data science team also needs a reliable way to retain history of the models they build and ensure that they can rebuild a specific version if needed. At any time, data scientists (or any other stakeholders) must have a way to accurately identify which version of a model is/was deployed.

Solution

Starting with version 1.4, Cloudera Data Science Workbench allows data scientists to build and deploy their own models as REST APIs. Data scientists can now select a Python or R function within a project file, and Cloudera Data Science Workbench will:

Create a snapshot of model code, model parameters, and dependencies.
Package a trained model into an immutable artifact and provide basic serving code.
Add a REST endpoint that automatically accepts input parameters matching the function, and that returns a data structure that matches the function’s return type.
Save the model along with some metadata.
Deploy a specified number of model API replicas, automatically load balanced.