SOA-C03 Exam Dumps - AWS Certified CloudOps Engineer - Associate

Comprehensive and Detailed Explanation From Exact Extract of AWS CloudOps Documents:

The correct answer is D because target tracking scaling policies are designed to automatically maintain a specific metric at a desired target value with the least administrative effort. AWS CloudOps documentation states that target tracking works like a thermostat, continuously adjusting capacity to keep the selected metric close to the defined target.

By specifying a target value of 40% average CPU utilization, the Auto Scaling group automatically scales out or in based on real-time demand without requiring manual thresholds, multiple alarms, or predefined scaling steps. This approach is fully managed by AWS and is the most operationally efficient option.

Option A is incorrect because scheduled scaling is based on predictable traffic patterns and cannot respond dynamically to real-time load changes. Option B is incorrect because simple scaling reacts only after an alarm is triggered and does not continuously maintain a target value. Option C is less efficient because step scaling requires additional configuration and tuning of scaling steps.

AWS CloudOps best practices clearly recommend target tracking scaling policies for maintaining steady performance metrics with minimal operational overhead.

In this scenario, the EC2 instances pass their EC2 status checks, indicating that the operating system is responsive. However, the application hosted on the instance is failing intermittently, returning HTTP 500 errors. This demonstrates a discrepancy between the instance-level health and the application-level health.

According to AWS CloudOps best practices under Monitoring, Logging, Analysis, Remediation and Performance Optimization (SOA-C03 Domain 1), Auto Scaling groups should incorporate Elastic Load Balancing (ELB) health checks instead of relying solely on EC2 status checks. The ELB health check probes the application endpoint (for example, HTTP or HTTPS target group health checks), ensuring that the application itself is functioning correctly.

When an instance fails an ELB health check, Amazon EC2 Auto Scaling will automatically mark the instance as unhealthy and replace it with a new one, ensuring continuous availability and performance optimization.

Extract from AWS CloudOps (SOA-C03) Study Guide – Domain 1:

“Implement monitoring and health checks using ALB and EC2 Auto Scaling integration. Application Load Balancer health checks allow Auto Scaling to terminate and replace instances that fail application-level health checks, ensuring consistent application performance.”

Extract from AWS Auto Scaling Documentation:

“When you enable the ELB health check type for your Auto Scaling group, Amazon EC2 Auto Scaling considers both EC2 status checks and Elastic Load Balancing health checks to determine instance health. If an instance fails the ELB health check, it is automatically replaced.”

Therefore, the correct answer is B, as it ensures proper application-level monitoring and remediation using ALB-integrated ELB health checks—a core CloudOps operational practice for proactive incident response and availability assurance.

References (AWS CloudOps Verified Source Extracts):

AWS Certified CloudOps Engineer – Associate (SOA-C03) Exam Guide: Domain 1 – Monitoring, Logging, and Remediation.

AWS Auto Scaling User Guide: Health checks for Auto Scaling instances (Elastic Load Balancing integration).

AWS Well-Architected Framework – Operational Excellence and Reliability Pillars.

AWS Elastic Load Balancing Developer Guide – Target group health checks and monitoring.

According to the AWS Cloud Operations and Cost Management documentation, AWS Budgets is the recommended service to track and alert on cost thresholds across all AWS accounts and resources. It allows users to define cost, usage, or reservation budgets, and configure notifications to trigger when usage or cost reaches defined percentages of the budgeted value (e.g., 75%, 90%, 100%).

The AWS Budgets system integrates natively with Amazon Simple Notification Service (SNS) to deliver alerts to an email distribution list or SNS topic subscribers. AWS Budgets supports granular cost filters, including specific service categories such as data transfer, regions, or linked accounts, ensuring precise visibility into inter-Region transfer costs.

By contrast, CloudWatch billing alarms (Option B) monitor total account charges only and do not allow detailed service-level filtering, such as data transfer between Regions. Cost and Usage Reports (Option A) are for detailed cost analysis, not real-time alerting, and VPC Flow Logs (Option D) capture traffic data, not billing or cost-based metrics.

Thus, using AWS Budgets with a 75% alert threshold best satisfies the operational and notification requirements.