Amazon Web Services Updated MLA-C01 Exam Questions and Answers by harlie

This issue occurs because target tracking auto scaling allows the endpoint to scale down to zero, and scaling up only happens after traffic arrives. At the start of the business day, no instances are running, so the first requests experience cold-start delays.

AWS documentation for Amazon SageMaker recommends using scheduled or step scaling policies when predictable traffic patterns exist. In this case, business hours are predictable, so the best practice is to proactively scale the endpoint before traffic arrives.

Option D correctly uses Amazon CloudWatch alarms with step scaling to increase the minimum instance count from zero to one at the start of the business day. This ensures at least one warm instance is ready to handle requests immediately, eliminating startup latency.

Options A, B, and C do not guarantee instance availability before traffic begins. Cooldown tuning and metric changes only react after load is detected.

Therefore, scheduled step scaling using CloudWatch alarms is the correct solution.

AWS best practices recommend event-driven architectures to automate ML workflows with minimal operational overhead. Amazon EventBridge natively integrates with Amazon S3 and Amazon SageMaker Pipelines, making it the most efficient solution for triggering retraining when new data arrives.

Amazon S3 automatically emits object creation events. By creating an EventBridge rule that listens for these events and targets a SageMaker Pipeline execution, the pipeline can start immediately when new training data is uploaded. This solution requires no custom code, no polling, and no infrastructure management.

Option A is incorrect because S3 lifecycle rules manage storage transitions, not workflow execution. Option B introduces custom code and periodic scanning, which increases operational complexity and cost. Option D (MWAA) is powerful but requires maintaining an Airflow environment and is unnecessary for a simple event-based trigger.

AWS documentation explicitly highlights EventBridge + SageMaker Pipelines as the recommended pattern for automated retraining workflows triggered by data arrival.

Therefore, Option C is the correct and AWS-verified answer.

The requirement has two key constraints: detect class imbalance and balance classes without losing any existing data. AWS provides Amazon SageMaker Clarify as the native tool to detect pre-training bias, including class imbalance (CI). CI measures differences in label distributions between classes, and a CI value greater than 0 indicates imbalance.

Once imbalance is detected, the engineer must rebalance the dataset without discarding data. Random undersampling would remove samples from the majority class, violating the requirement. Instead, oversampling is required. SMOTE (Synthetic Minority Oversampling Technique) creates synthetic samples for the minority class, preserving all original data while improving class balance.

Amazon SageMaker Data Wrangler natively supports SMOTE, making it the correct AWS-managed tool for this preprocessing task.

Options C and D are incorrect because SageMaker JumpStart is used for pretrained models and solutions, not for bias detection reporting. Option A is incorrect because it uses undersampling and misinterprets CI = 0 (which actually indicates no imbalance).

Therefore, detecting imbalance with SageMaker Clarify and correcting it using SMOTE in Data Wrangler is the correct solution.

The problem is a time series forecasting task with historical data and categorical features. Amazon SageMaker DeepAR is purpose-built for this use case. DeepAR uses recurrent neural networks to learn temporal patterns across multiple related time series and supports categorical covariates.

The context length hyperparameter controls how much historical data the model uses as input, while the prediction length specifies how far into the future the model forecasts. Correctly setting these hyperparameters is critical for capturing trends and seasonality.

XGBoost is a general-purpose tabular algorithm and does not model temporal dependencies natively. k-means is a clustering algorithm. Random Cut Forest is used for anomaly detection, not forecasting.

Therefore, DeepAR with appropriate context and prediction lengths is the correct and AWS-recommended solution.