Databricks-Machine-Learning-Professional Exam Dumps - Databricks Certified Machine Learning Professional

MLflow provides a utility function mlflow.models.signature.infer_signature that can infer the input schema and the output schema of a model from a sample dataset. The input schema and the output schema are represented as mlflow.types.schema.Schema objects, which define the names, data types, and shapes of the model inputs and outputs. The infer_signature function can be used for any model that implements a predict method that takes a pandas DataFrame or a numpy array as input and returns a pandas DataFrame, a pandas Series, a numpy array, or a list as output. The infer_signature function can also be used for models that implement a transform method that takes a pandas DataFrame as input and returns a pandas DataFrame as output. The infer_signature function can be used before logging the model with MLflow, as it does not require the model to be in MLflow format or registered with MLflow Model Registry. References:

• MLflow Models Documentation, Model Signature and Input Example, p. 6-7
• mlflow.types.schema Documentation, p. 1-2
• Machine Learning Engineering with MLflow, Managing Model Signatures and Schemas, p. 1

To obtain run-level results for an experiment ID in a Spark DataFrame, you can use the mlflow.search_runs(exp_id) function. This function takes a filter string, which acts as a filter to the query, and returns a pandas.DataFrame of runs, where each metric, parameter, and tag are expanded into their own columns named metrics., params., and tags.* respectively1. You can then convert the pandas.DataFrame to a Spark DataFrame using the spark.createDataFrame() method2. The other options are incorrect because:

• Option A: client.list_run_infos(exp_id) will return a list of RunInfo objects, not a DataFrame3.
• Option B: spark.read.format(“delta”).load(exp_id) will not work for MLflow experiments, as it expects a Delta table path, not an experiment ID4.
• Option C: There is a way to programmatically return row-level results from an MLflow experiment using the mlflow.search_runs(exp_id) function1.
• Option E: spark.read.format(“mlflow-experiment”).load(exp_id) is not a valid format for reading MLflow experiments, as there is no such format registered in Spark5. References: Search Runs, Create a DataFrame from an RDD, a list or a pandas.DataFrame, MlflowClient.list_run_infos, Delta Lake Quickstart, spark.read.format

The correct line of code is “MODEL_VERSION_TRANSITIONED_STAGE”, which is the name of the event that occurs when a model version transitions to any stage in the MLflow Model Registry. This event can be used to trigger a webhook that will execute a Databricks Job based on the model version and the stage it transitions to. The other options are either invalid event names or too specific for the task.

References: MLflow Model Registry Webhooks, MLflow Model Registry Events

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

Streaming with Spark as a model deployment strategy means applying a machine learning model to data streams that are processed incrementally and continuously by Spark Structured Streaming. Spark Structured Streaming is a scalable and fault-tolerant stream processing engine that enables complex analytics on live data streams using the Dataset/DataFrame API1. Spark Structured Streaming supports various sources and sinks for streaming data, such as Kafka, Kinesis, TCP sockets, Delta tables, etc2. Spark Structured Streaming also supports various types of operations on streaming data, such as aggregations, windowing, joins, and stateful transformations3. To deploy a machine learning model on streaming data, you can use the MLflow model registry to managethe model lifecycle and versioning4. You can also use the MLflow model serving feature to serve the model as a REST API endpoint that can be invoked by Spark Structured Streaming5. Alternatively, you can use the UDF (user-defined function) feature to apply the model to streaming data within Spark Structured Streaming6.

The inference of incrementally processed records as soon as trigger is hit describes the streaming with Spark as a model deployment strategy. A trigger defines when the results of a streaming query should be written to the output sink. A trigger can be based on a processing time interval, a data size limit, or a continuous mode that writes the results as soon as they are available. The trigger ensures that the streaming query is executed incrementally and continuously, and the model inference is applied to the latest available data. The other options are incorrect because:

• Option A: The inference of batch processed records as soon as a trigger is hit does not describe streaming with Spark, but rather batch processing with Spark. Batch processing means applying a machine learning model to a finite set of data that is processed as a single job. Batch processing does not require a trigger, as the results are written to the output sink when the job is completed.
• Option B: The inference of all types of records in real-time does not describe streaming with Spark, but rather a generic definition of real-time processing. Real-time processing means applying a machine learning model to data streams that are processed as soon as they arrive, with minimal latency. Real-time processing does not necessarily use Spark Structured Streaming, as there are other frameworks and tools that can support it, such as Apache Flink, Apache Storm, etc.
• Option C: The inference of batch processed records as soon as a Spark job is run does not describe streaming with Spark, but rather batch processing with Spark. Batch processing means applying a machine learning model to a finite set of data that is processed as a single job. Batch processing does not depend on a Spark job, as the model inference can be done outside of Spark, such as using a REST API endpoint, a command-line tool, etc.
• Option E: The inference of incrementally processed records as soon as a Spark job is run does not describe streaming with Spark, but rather a contradiction. Incrementally processed records imply streaming processing, while a Spark job implies batch processing. Streaming processing and batch processing are different paradigms of data processing, and cannot be mixed in this way. References: Structured Streaming Programming Guide, Input Sources and Output Sinks, Operations on streaming DataFrames/Datasets, MLflow Model Registry, MLflow Model Serving, Apply machine learning models, [Triggers], [Trigger Types], [Batch Processing], [Real-time Processing], [Real-time Data Processing Frameworks], [Deploy machine learning models], [Batch vs Streaming Processing]

To compute predictions for spark_df when the missing feature values can be found in the Feature Store by searching for features by customer_id, you can use the following code block:

Python

# Get the missing features from the Feature Store using the model URI and the customer_id column

df = fs.get_missing_features(spark_df, model_uri, lookup_key="customer_id")

# Score the DataFrame using the model URI and the Feature Store Client

fs.score_batch(model_uri, df)

AI-generated code. Review and use carefully. More info on FAQ.

The fs.get_missing_features method takes a Spark DataFrame, a model URI, and a lookup key as arguments. It returns a new Spark DataFrame that contains the originalcolumns plus the missing features that are required by the model. The missing features are retrieved from the Feature Store by joining the DataFrame with the feature tables using the lookup key. The lookup key must match the primary key of the feature tables. The model URI must point to a registered model that was trained using features from the Feature Store1.

The fs.score_batch method takes a model URI and a Spark DataFrame as arguments. It applies the model to the DataFrame and returns a new Spark DataFrame that contains the original columns plus a prediction column. The model URI must point to a registered model that was trained using features from the Feature Store2.

The other options are incorrect because:

• Option A: fs.score_model is not a valid method name, as it is missing an underscore. The correct method name is fs.score_batch2.
• Option B: fs.score_model without getting the missing features will not work, as the model expects the DataFrame to have all the features that were used for training. The correct way is to use fs.get_missing_features before fs.score_batch12.
• Option D: fs.score_batch without getting the missing features will not work, as the model expects the DataFrame to have all the features that were used for training. The correct way is to use fs.get_missing_features before fs.score_batch12.
• Option E: fs.score_batch without specifying the lookup key will not work, as the fs.get_missing_features method requires a lookup key to join the DataFrame with the feature tables. The correct way is to use fs.get_missing_features with the lookup key “customer_id” before fs.score_batch12. References: Get missing features, Score batch

Containers are a type of software packaging that can assist in real-time deployments by packaging software with its own application, tools, and libraries. Containers are isolated and portable environments that run on a shared operating system, but have their ownfile system, dependencies, configuration, and resources. Containers can help developers and operators to build, test, and deploy software faster, easier, and more reliably, as they ensure that the software runs the same way in any environment, whether it is a developer’s laptop, a test server, or a production cluster. Containers can also help to achieve scalability, high availability, and load balancing, as they can be easily created, destroyed, replicated, and orchestrated using tools such as Kubernetes, Docker Swarm, or Amazon ECS. Containers can also integrate with other tools and services, such as MLflow, Databricks, AWS CodeDeploy, and Google Cloud Deployment Manager, to enable end-to-end machine learning pipelines with tracking, reproducibility, and governance1234 References:

• How to Package Your Application’s Infrastructure with Docker
• 21 open source DevOps tools (and what they do)
• Microservices [What is it & Top Benefits]
• 9 Best Software Deployment Tools for 2023 (Paid & Free)

Batch serving is a type of model deployment where predictions are computed in advance and stored for later use. This can be useful when the feature values are known ahead of time and the predictions need to be delivered quickly. Querying stored predictions can be faster than computing predictions in real-time, especially if the model is complex or the data volume is high. Real-time serving is a type of model deployment where predictions are computed on-demand at query time. This can be useful when the feature values are not known in advance or the predictions need to be up-to-date. However, computing predictions in real-time can be slower than querying stored predictions, especially if the model is simple or the data volume is low. References: [Batch Serving], [Real-time Serving] Message has links.

MLflow Autologging is a feature that automatically logs parameters, metrics, and artifacts for machine learning frameworks, such as Hyperopt, without requiring any code changes. When using MLflow Autologging with Hyperopt, MLflow will automatically create a parent run for the hyperparameter tuning process and a child run for each unique combination of hyperparameter values. This way, the user can easily compare and visualize the results of different hyperparameter settings in the MLflow UI. MLflow Autologging also supports nested runs, which means that if the user starts a manual run before calling fmin, the parent run will be nested under the manual run. This allows the user to organize and group related runs together. References: MLflow Autologging, Hyperparameter Tuning with MLflow, Apache Spark MLlib and Hyperopt, Using MLFlow with Hyperopt for Automated Machine Learning, Parallelize hyperparameter tuning with scikit-learn and MLflow, [Optimizing Model Performance with MLflow and Hyperopt: From Hyperparameter Tuning to Serving]

Jensen-Shannon (JS) distance is a symmetric measure of the distance between two probability distributions. It is based on the Kullback-Leibler (KL) divergence, but unlike KL, it does not depend on which distribution is considered the reference and which is considered the comparison. JS distance is also bounded between 0 and 1, which makes it easier to interpret and compare across different features.

Kolmogorov-Smirnov (KS) test is a non-parametric test that compares the cumulative distribution functions (CDFs) of two samples. It calculates the maximum difference between the CDFs and compares it to a critical value to determine if the samples are from the same distribution. KS test is sensitive to the shape, location, and scale of the distributions, but it can also be too sensitive for large datasets, where small changes can result in significant differences.

JS distance is more robust than KS test for numeric feature drift detection because it can handle large datasets without being too sensitive to minor fluctuations. It can also capture changes in the shape and spread of the distributions, not just the location. JS distance does not require any manual threshold or cutoff determinations, unlike KS test, which requires choosing a significance level and a critical value. JS distance can also be generalized to multivariate cases, while KS test is limited to univariate cases. References:

• Which test is the best? We compared 5 methods to detect data drift on large datasets
• The Jensen-Shannon Divergence: A Measure of Distance Between Probability Distributions
• Kullback–Leibler vs Kolmogorov-Smirnov distance

The fs.read_table operation can be used to return a Spark DataFrame of a data set associated with a Feature Store table. This operation takes the name of the Feature Store table and an optional time travel specification as arguments. The fs.create_table operation is used to create a new Feature Store table from a Spark DataFrame. The fs.write_table operation is used to write data to an existing Feature Store table. The fs.get_table operation is used to get the metadata of a Feature Store table, not the data itself. There is a way to accomplish this task with fs, so option D is incorrect. References:

• Feature Store Client
• Feature Store Tables

To replace all data in a feature table with newly computed data, you can use the fs.write_table method with the mode argument set to “overwrite”. This will overwrite the existing data in the feature table with the data in the provided DataFrame. The other options are incorrect because:

• Option A: fs.create_table will create a new feature table, not replace the data in an existing one. If the feature table already exists, it will raise an exception.
• Option B: fs.write_table without specifying the mode argument will use the default mode of “merge”, which will merge the new data with the existing data, not replace it.
• Option C: fs.write table is not a valid method name, as it is missing an underscore. Also, the mode argument of “merge” will not replace the data, but merge it with the existing data.
• Option E: fs.create_table with the mode argument of “merge” is not a valid combination, as the mode argument is only applicable for fs.write_table. Also, the mode argument of “merge” will not replace the data, but merge it with the existing data. References: Databricks FeatureStoreClient, Work with features in Workspace Feature Store

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

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]

 The mlflow.register_model function takes two arguments: model_uri and name. The model_uri is the URI of the model that was logged to MLflow, which can be obtained from the best run object. The name is the name of the registered model in the MLflow Model Registry. Therefore, the correct line of code to register the model is:

mlflow.register_model(model_uri, “best_model”)

This will create a new registered model with the name “best_model” and register the model version from the best run as the first version of that model.

References:

• [mlflow.register_model — MLflow 1.22.0 documentation]
• [MLflow Model Registry — Databricks Documentation]
• [Manage MLflow Models — Databricks Documentation] Message has links.