Databricks-Machine-Learning-Professional Exam Results

An HTTP Webhook is a mechanism that allows you to register a callback that is triggered by an event, such as a model registry event. The callback is an HTTP request that is sent to a specified URL, which can invoke an action or a notification on another platform or service. An HTTP Webhook is required for use cases that involve integrating the model registry with external tools or workflows that are not supported by Databricks1.

Sending a message to a Slack channel when a model version transitions stages is a use case that requires the use of an HTTP Webhook. This is because Slack is an external platform that is not natively integrated with Databricks, and the model registry events are not directly accessible by Slack. Therefore, to send a message to a Slack channel, you need to register an HTTP Webhook that is triggered by the model registry event of interest, such as MODEL_VERSION_TRANSITIONED_STAGE. The HTTP Webhook then sends a request to the Slack API endpoint that corresponds to the channel and the message content2.

The other options are incorrect because:

• Option A: Starting a testing job when a new model is registered does not require the use of an HTTP Webhook, but rather a job registry webhook. A job registry webhook is a type of webhook that triggers a job in a Databricks workspace when a model registry event occurs. A job registry webhook can be created using the Databricks REST API or the Python client databricks-registry-webhooks on PyPI3.
• Option B: Updating data in a source table for a Databricks SQL dashboard when a model version transitions to the Production stage does not require the use of an HTTP Webhook, but rather a Databricks SQL trigger. A Databricks SQL trigger is a mechanism that allows you to execute a SQL query or a notebook when a specified condition is met, such as a time interval or a file arrival. A Databricks SQL trigger can be created using the Databricks SQL UI or the Databricks REST API4.
• Option C: Sending an email alert when an automated testing job fails does not require the use of an HTTP Webhook, but rather a job alert. A job alert is a feature that allows you to send an email notification when a job run meets a specifiedcondition, such as a failure, a timeout, or a success. A job alert can be created using the Jobs UI or the Databricks REST API5.
• Option D: None of these use cases require the use of an HTTP Webhook is incorrect, as option E does require the use of an HTTP Webhook. References: MLflow Model Registry Webhooks on Databricks, Streamline MLOps With MLflow Model Registry Webhooks, Databricks SQL Triggers, Job Alerts, [Slack API]

A pyfunc model is a generic Python model that can be loaded and used to make predictions using any Python ML library. By logging a custom model class that implements the preprocessing logic as a pyfunc model, the same logic will be applied when loading the model and calling the predict method on new data. This ensures consistency and reproducibility of the model predictions. The fit method is not relevant for loading a logged model, as it is only used for training the model. The pyfunc model does not affect the parallelizability or the need for pipeline-like objects of the model deployment. References: mlflow.pyfunc, Creating custom Pyfunc models

The MLflow Model Registry provides a centralized model store, set of APIs, and UI, to collaboratively manage the full lifecycle of an MLflow Model. It provides model lineage, model versioning, model aliasing, model tagging, and annotations. The Model Registry defines four model stages that represent the lifecycle of a model: None, Staging, Production, and Archived. Each model stage has a different meaning and purpose:

• None: This is the default stage when a new model version is registered. It indicates that the model version is not ready for any downstream use cases and needs further development or testing.
• Staging: This stage indicates that the model version is ready for testing or validation in a pre-production environment. It can be used for quality assurance, user acceptance testing, or performance evaluation before moving to production.
• Production: This stage indicates that the model version is ready for deployment in a production environment. It can be used for serving predictions, scoring data, or supporting business decisions. Only one model version per registered model can be in the production stage at a time.
• Archived: This stage indicates that the model version is no longer in active use and can be safely deleted or moved to a long-term storage. It can be used for historical or audit purposes, or for restoring a previous model version if needed.

References:

• MLflow Model Registry Documentation, p. 1-2
• Introducing the MLflow Model Registry - Databricks, p. 1-2
• Manage MLflow Models — Databricks Documentation, p. 1-2

Concept drift in machine learning and data mining refers to the change in the relationships between input and output data in the underlying problem over time. In other domains, this change maybe called “covariate shift,” “dataset shift,” or “nonstationarity.” Concept drift can affect the performance and accuracy of predictive models that assume a static relationship between input and output variables. Concept drift can be caused by various factors, such as changes in user behavior, environmental conditions, market trends, etc. Concept drift can be detected and handled by various methods, such as periodic retraining, online learning, ensemble methods, etc References:

• Concept drift - Wikipedia
• A Gentle Introduction to Concept Drift in Machine Learning
• Model Drift & Machine Learning: Concept Drift, Feature Drift, Etc.
• Data Drift vs. Concept Drift: What Is the Difference?