Exam AWS Certified DevOps Engineer - Professional DOP-C02 topic 1 question 45 discussion

C is the right answer. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-recover.html

Explanation: Amazon CloudWatch provides system-wide visibility into resource utilization, application performance, and operational health. If a system status check fails, this implies there's a problem with the underlying EC2 system that may require AWS involvement to repair. The "Recover this instance" action for the system status check automatically recovers the instance if it becomes impaired due to an underlying issue.

C https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-recover.html In the event that AWS determines an instance is unavailable due to an underlying hardware issue, there are two mechanisms that you can configure for instance resiliency which can restore availability—simplified automatic recovery and Amazon CloudWatch action based recovery. This process is called instance recovery. The following are examples of underlying hardware issues that might require instance recovery: - Loss of network connectivity - Loss of system power - Software issues on the physical host - Hardware issues on the physical host that impact network reachability

C. This is the correct solution. By creating a CloudWatch alarm for the StatusCheckFailed System metric and configuring the alarm to trigger the "Recover this instance" action, the EC2 instance will be automatically recovered in the event of a system failure or power outage. This ensures the instance can be quickly recovered with minimal data loss, as the EBS volume remains attached during the recovery process. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-recover.html

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-recover.html

C is correct: recover is the right way A and B are irrelevant D: should not reboot in case of power failures

My Reason: StatusCheckFailed_System: This check monitors the AWS systems on which your instance runs1. For Example loss of network connectivity, loss of system power, software issues on the physical host, and hardware issues on the physical host that impact network reachability StatusCheckFailed_Instance: This check monitors the software and network configuration of your individual instance. These checks detect problems that require your involvement to repair. If an instance status check fails, it typically means that there’s an issue with the instance, such as a misconfigured network or a problem with the instance’s file system.

Correct Answer is C

A is incorrect. Simplified automatic recovery is not initiated for instances in an Auto Scaling group. If your instance is part of an Auto Scaling group with health checks enabled, then the instance is replaced when it becomes impaired. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-recover.html

C with recover action creates identical instance

C https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-recover.html There are only 2 ways to recover EC2 instances. Since this instance has EBS volumes, only the CloudWatch action based recovery is applicable.

Option D is the correct solution Option C is incorrect because modifying the AWS CloudFormation template requires manual intervention and cannot be automated. Additionally, creating an Amazon CloudWatch alarm to invoke the Lambda function after the failure event occurs doesn't provide an automated way to promote the replica instance. Therefore, Option D is the correct solution.

C is correct

option A is a better choice for this scenario because it ensures that there is always an EC2 instance running to serve the staging website, and the new instance will have the same configuration as the original instance, including the EBS volume, so there will be minimal data loss. Option C may result in some data loss since a new EBS volume will be created, and it may take longer to recover the instance since the EC2 action to recover the instance will need to be triggered by the Amazon CloudWatch alarm.

C for me