Q19 — AWS DOP-C02 Ch.2

Question 19 of 100 | ← Chapter 2

A company runs an application on Amazon EC2 instances in an Amazon EC2 Auto Scaling group. The EC2 instances are behind an Application Load Balancer (ALB). Users recently began experiencing errors when traffic was routed to certain EC2 instances. DevOps engineers found that the Auto Scaling group reported those problem instances as healthy, despite application-level errors. After resolving the issue, users confirmed normal behavior resumed on the affected instances. The company wants to ensure traffic routes only to instances that are both EC2-healthy and application-healthy. The company also wants the support team to receive notifications when traffic routing issues occur.

• A. Configure the Auto Scaling group to use ELB health checks. Enable AWS Config. Create an AWS Config rule to ensure any new Auto Scaling groups use ELB health checks. Create an Amazon Simple Notification Service (Amazon SNS) topic to notify the support team of traffic routing configuration changes. Configure the AWS Config rule to send notifications to the topic. ✓
• B. Configure the Auto Scaling group to use EC2 health checks. Enable AWS Config. Create an AWS Config rule to ensure any new Auto Scaling groups use EC2 health checks. Create an Amazon Simple Notification Service (Amazon SNS) topic to notify the support team of traffic routing configuration changes. Configure the AWS Config rule to send notifications to the topic.
• C. Configure the Auto Scaling group to use EC2 health checks. Create an Amazon CloudWatch Synthetics canary to monitor the application. Create a CloudWatch alarm that triggers when the CloudWatch Synthetics canary fails. Configure the alarm to notify the support team when in ALARM state.
• D. Configure the Auto Scaling group to use ELB health checks. Create an Amazon CloudWatch Synthetics canary to monitor the application. Create a CloudWatch alarm that triggers when the CloudWatch Synthetics canary fails. Configure the alarm to notify the support team when in ALARM state.

Correct Answer: A. Configure the Auto Scaling group to use ELB health checks. Enable AWS Config. Create an AWS Config rule to ensure any new Auto Scaling groups use ELB health checks. Create an Amazon Simple Notification Service (Amazon SNS) topic to notify the support team of traffic routing configuration changes. Configure the AWS Config rule to send notifications to the topic.

Explanation

This question involves Amazon EC2 Auto Scaling group health check mechanisms with an Application Load Balancer (ALB) and AWS Config governance with notification. According to AWS documentation, Auto Scaling groups support two health check types: EC2 status checks (which verify instance hardware/network status only) and ELB health checks (which evaluate application-layer health per ALB configuration). When application errors are not detected by EC2 status checks, switching to ELB health checks ensures traffic routes only to application-healthy instances. AWS Config audits resource configuration compliance, ensuring new Auto Scaling groups consistently use ELB health checks. Integration with Amazon SNS provides change-notification capability. Option A satisfies both the health check remediation and notification requirements. Option B’s EC2 health checks cannot detect application errors; Options C and D introduce CloudWatch Synthetics canaries, which provide proactive monitoring but do not replace or configure the Auto Scaling group’s built-in health check mechanism for traffic routing control.