Q97 — AWS SOA-C02 Ch.1

Question 97 of 100 | ← Chapter 1

A SysOps administrator is setting up an automated process to recover an Amazon EC2 instance in the event of an underlying hardware failure. The recovered instance must have the same private IP address and the same Elastic IP address that the original instance had. The SysOps team must receive an email notification when the recovery process is initiated. Which solution will meet these requirements?

• A. Create an Amazon CloudWatch alarm for the EC2 instance, and specify the StatusCheckFailed_Instance metric. Add an EC2 action to the alarm to recover the instance. Add an alarm notification to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic. Subscribe the SysOps team email address to the SNS topic.
• B. Create an Amazon CloudWatch alarm for the EC2 instance, and specify the StatusCheckFailed_System metric. Add an EC2 action to the alarm to recover the instance. Add an alarm notification to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic. Subscribe the SysOps team email address to the SNS topic.
• C. Create an Auto Scaling group across three different subnets in the same Availability Zone with a minimum, maximum, and desired size of 1. Configure the Auto Scaling group to use a launch template that specifies the private IP address and the Elastic IP address. Add an activity notification for the Auto Scaling group to send an email message to the SysOps team through Amazon Simple Email Service (Amazon SES).
• D. Create an Auto Scaling group across three Availability Zones with a minimum, maximum, and desired size of 1. Configure the Auto Scaling group to use a launch template that specifies the private IP address and the Elastic IP address. Add an activity notification for the Auto Scaling group to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic. Subscribe the SysOps team email address to the SNS topic. ✓

Correct Answer: D. Create an Auto Scaling group across three Availability Zones with a minimum, maximum, and desired size of 1. Configure the Auto Scaling group to use a launch template that specifies the private IP address and the Elastic IP address. Add an activity notification for the Auto Scaling group to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic. Subscribe the SysOps team email address to the SNS topic.

Explanation

题目考察使用CloudWatch监控EC2实例状态并在硬件故障时自动恢复的能力。AWS文档指出，StatusCheckFailed_System指标监测主机级别的硬件问题，而StatusCheckFailed_Instance监测实例操作系统问题。当使用EC2恢复功能时，实例保留相同的私有IP和EIP。Auto Scaling组无法保证单实例固定IP，尤其是跨子网或AZ时。选项B的CloudWatch警报配置了正确的系统状态检查指标，触发恢复并发送SNS通知，符合恢复IP和通知要求。其余选项或错误选择实例状态检查，或使用Auto Scaling导致IP变更，或使用不匹配的通知服务。