AWS Certified Solutions Architect Professional SAP-C02 Practice Question

The correct answer is to use CloudWatch Contributor Insights on ALB access logs. CloudWatch Contributor Insights is specifically designed to analyze high-cardinality data, like log files, to identify the top contributors impacting system performance. By analyzing the target_processing_time field in the ALB access logs, this solution directly addresses the problem of identifying which specific requests or clients are causing the latency spikes, without requiring complex, manual query writing. This approach is the most direct and efficient method for root cause analysis in this scenario.

The option to use CloudWatch Logs Insights is plausible but less effective. While Logs Insights is a powerful tool for ad-hoc log analysis, it requires manually crafting and scheduling queries. Contributor Insights automates the 'top-N' contributor analysis, making it faster and more efficient for this specific use case.

The anomaly detection option is useful for alerting that a problem is occurring but does not provide insight into the cause. The team would still need to perform a manual investigation to find the root cause, which does not meet the requirement to identify the specific contributors.

Increasing the EC2 monitoring frequency and creating a composite alarm is also a reactive approach. While it can alert the team to the condition (high latency without high CPU), it does not help identify the source of the problematic requests, which is the core requirement stated in the question.