DOP-C02 Question 281
Select 2Your organization runs a critical web application on Amazon EC2 instances behind an Auto Scaling group. To improve resilience, you need to implement a monitoring and recovery mechanism that automatically detects and recovers failed EC2 instances. Additionally, the operations team wants to be notified immediately when such failures occur. Which combination of actions should you take to meet these requirements?
- A
Set up a CloudWatch alarm to monitor the EC2 instance's status checks and configure it to trigger an Amazon SNS topic to notify the operations team.
- B
Enable EC2 automatic recovery by creating a CloudWatch alarm that monitors the EC2 instance's System Status Check metric and triggers the 'Recover this instance' action.
- C
Attach an Amazon S3 bucket to the EC2 instance to automatically store logs during failure recovery.
- D
Create an Auto Scaling lifecycle hook to terminate and replace unhealthy EC2 instances and configure a CloudWatch alarm to notify the operations team via an Amazon SNS topic.
- E
Use an AWS Lambda function triggered by a CloudWatch alarm to restart the EC2 instance upon detecting a failure and send a notification to the operations team.
Show answer and explanation
Correct answers: A, B
Explanation
To meet the requirements, you must implement both monitoring and recovery mechanisms. Option 1 ensures the operations team is notified of failures via an Amazon SNS topic when a CloudWatch alarm detects an issue. Option 2 ensures failed EC2 instances are automatically recovered using the 'Recover this instance' action linked to a CloudWatch alarm. These two actions together fulfill the criteria for resilience and notification.
- A. Correct.
This option is correct because setting up a CloudWatch alarm to monitor the EC2 instance's status checks and triggering an Amazon SNS topic ensures the operations team is notified when a failure is detected.
- B. Correct.
This option is correct because enabling EC2 automatic recovery with a CloudWatch alarm configured to the 'Recover this instance' action ensures failed instances are automatically recovered.
- C. Incorrect.
This option is incorrect because attaching an S3 bucket to the EC2 instance does not address the monitoring, recovery, or notification requirements.
- D. Incorrect.
This option is incorrect because while Auto Scaling lifecycle hooks can handle instance replacement, it is not necessary to use them in this scenario since the focus is on EC2 automatic recovery and notification.
- E. Incorrect.
This option is incorrect because restarting an EC2 instance via a Lambda function is not the intended solution when automatic recovery and CloudWatch alarms are specifically designed for such use cases.