Q24 — AWS SOA-C02 Ch.1

Question 24 of 100 | ← Chapter 1

A company hosts a web application on Amazon EC2 instances behind an Application Load Balancer. The instances are in an Amazon EC2 Auto Scaling group. The application is accessed with a public URL. A SysOps administrator needs to implement a monitoring solution that checks the availability of the application and follows the same routes and actions as a customer. The SysOps administrator must receive a notification if less than 95% of the monitoring runs find no errors. Which solution will meet these requirements?

• A. Create an Amazon CloudWatch Synthetics canary with a script that follows customer routes. Schedule the canary to run on a recurring schedule. Create a CloudWatch alarm that publishes a message to an Amazon Simple Notification Service (Amazon SNS) topic when the SuccessPercent metric is less than 95%. ✓
• B. Create Amazon Route 53 health checks that monitor the availability of the endpoint. Create Amazon CloudWatch alarms that publish a message to an Amazon Simple Notification Service (Amazon SNS) topic when the HealthCheckPercentageHealthy metric is less than 95%.
• C. Create a single AWS Lambda function to check whether the endpoints are available for each customer path. Schedule the Lambda function by using Amazon EventBridge (Amazon CloudWatch Events). Configure the Lambda function to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic when an endpoint returns an error.
• D. Create an AWS Lambda function for each customer path to check whether that specific endpoint is available. Schedule the Lambda functions by using Amazon EventBridge (Amazon CloudWatch Events). Configure each Lambda function to publish a custom metric to Amazon CloudWatch for the endpoint status. Create CloudWatch alarms based on each custom metric to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic when an alarm is in the ALARM state.

Correct Answer: A. Create an Amazon CloudWatch Synthetics canary with a script that follows customer routes. Schedule the canary to run on a recurring schedule. Create a CloudWatch alarm that publishes a message to an Amazon Simple Notification Service (Amazon SNS) topic when the SuccessPercent metric is less than 95%.

Explanation

该题考察使用Amazon CloudWatch Synthetics进行应用可用性监控的方案设计。题干要求监控需模拟客户访问路径，并在错误率超过5%时告警。Amazon CloudWatch Synthetics的Canary功能允许创建脚本模拟用户行为，定期执行以检测应用各路径的可用性。其内置的SuccessPercent指标直接反映成功率，结合CloudWatch Alarm可配置在成功率低于95%时触发SNS通知。选项B的Route 53健康检查仅验证端点可达性，无法模拟复杂用户路径。选项C/D通过自定义Lambda方案虽可行，但需额外开发维护多条路径检查逻辑，且自定义指标告警配置复杂度高于Synthetics的集成方案。