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

The correct solution is B. Configure RDS Proxy, because RDS Proxy is specifically designed to manage and pool database connections for Amazon Aurora and Amazon RDS. AWS CloudOps documentation states that RDS Proxy reduces database load and prevents connection exhaustion by reusing existing connections and managing spikes in application demand.

In this scenario, the ecommerce application maintains many idle connections, which consume database connection slots even when not actively used. During peak traffic, new connections cannot be established, resulting in the ”Too many connections” error. RDS Proxy sits between the application and the Aurora DB cluster, maintaining a smaller, efficient pool of database connections and multiplexing application requests over those connections.

Option A is incorrect because RCUs and WCUs apply to DynamoDB, not Aurora. Option C is incorrect because enhanced networking improves network throughput and latency but does not manage database connections. Option D is incorrect because changing instance types does not address idle connection buildup and can still result in connection exhaustion.

AWS CloudOps best practices recommend RDS Proxy for applications with connection-heavy workloads, unpredictable traffic patterns, or serverless components.

Amazon RDS User Guide — RDS Proxy concepts and benefits

Amazon Aurora User Guide — Managing database connections

AWS SysOps Administrator Study Guide — Database reliability and scaling

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.

According to the AWS Cloud Operations and Compute documentation, when workloads exhibit predictable traffic patterns, the best practice is to use scheduled scaling for Amazon EC2 Auto Scaling groups.

With scheduled scaling, administrators can predefine the desired capacity of an Auto Scaling group to increase before anticipated demand (in this case, before the 2-hour peak) and scale back down afterward. This ensures that sufficient compute capacity is provisioned proactively, avoiding performance degradation while maintaining cost efficiency.

AWS notes: ”Scheduled actions enable scaling your Auto Scaling group at predictable times, allowing you to pre-warm instances before demand spikes.”

Manual scaling (Option D) adds operational overhead. Adjusting launch templates (Option B) doesn’t affect scaling behavior, and permanently increasing minimum capacity (Option A) wastes resources outside of peak hours.

Thus, Option C provides an automated, cost-effective, and operationally efficient CloudOps solution.

As per the AWS Cloud Operations and Event Monitoring documentation, the most efficient method for event-driven notification is to use Amazon EventBridge to detect specific EC2 API events and trigger a Simple Notification Service (SNS) alert.

EventBridge continuously monitors AWS service events, including RunInstances, which signals the creation of new EC2 instances. When such an event occurs, EventBridge sends it to an SNS topic, which then immediately emails subscribed recipients — in this case, the architecture team.

This combination provides real-time, serverless notifications with minimal management. SQS (Option C) is designed for queue-based processing, not direct user alerts. User data scripts (Option A) and custom polling with Lambda (Option D) introduce unnecessary operational complexity and latency.

Hence, Option B is the correct and AWS-recommended CloudOps design for immediate launch notifications.