Question #1589
A company operates a nightly batch processing workload on Amazon EC2 instances spread across two Availability Zones in the us-west-2 Region. Under normal conditions, the workload runs on three instances but needs to scale up to eight instances every night. The company seeks a solution that minimizes operational overhead while ensuring the instances scale appropriately for the increased demand.
Which solution meets these requirements with the LEAST operational overhead?
Configure a CloudWatch Events rule to trigger an AWS Lambda function that modifies the Auto Scaling group capacity.
Configure an Auto Scaling group with a scheduled action to adjust capacity at specific times.
Configure an Auto Scaling group that requires manual scaling adjustments each night.
Configure an Auto Scaling group that uses dynamic scaling policies based on Amazon CloudWatch metrics.
Explanation
Option B is correct because Auto Scaling scheduled actions allow predefined scaling adjustments at specific times, requiring no manual intervention or complex setups. This is ideal for predictable, recurring workloads like nightly batch processing.
- Option A adds complexity by requiring a Lambda function and CloudWatch Events rule, increasing operational overhead.
- Option C relies on manual scaling, which contradicts the requirement to minimize operational effort.
- Option D uses dynamic scaling based on metrics, which is better for unpredictable traffic patterns and introduces latency compared to scheduled scaling.
Key Points: Use Auto Scaling scheduled actions for predictable scaling patterns; avoid manual processes or unnecessary automation layers to reduce overhead.
Answer
The correct answer is: B