SOA-C02 Reliability and Business Continuity Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Use AWS Systems Manager to replace the underlying host.

  Why it's wrong here

  AWS Systems Manager does not provide a native operation to replace the underlying host of an EC2 instance. While SSM can run automation documents or patches, it cannot directly interact with the Auto Scaling group’s health-check lifecycle to terminate and replace an unhealthy instance. Relying on SSM for host replacement would require custom scripting and manual trigger, which does not satisfy the requirement for automatic recovery.

• ✗

  Manually reboot the instance from the EC2 console.

  Why it's wrong here

  Manually rebooting the instance from the EC2 console is a reactive, one-time action that requires human intervention. It does not scale to multiple instances and does not integrate with the Auto Scaling group’s health-check mechanism, so any future status-check failures would still go unaddressed. Automatic recovery should be handled by the ASG itself, not by an administrator manually rebooting instances.

• ✗

  Create a CloudWatch alarm that triggers an SNS notification to the administrator.

  Why it's wrong here

  A CloudWatch alarm that simply sends an SNS notification only informs the administrator of a problem; it does not perform any recovery action. Without an automated downstream step (such as Lambda invoking an ASG action), the instance remains unhealthy and the notification does not replace or remediate the failing instance. This option fails to meet the requirement because it lacks any automated corrective behavior.

• ✓

  Configure the Auto Scaling group to use EC2 status checks for health checks and set the health check grace period appropriately.

  Why this is correct

  Configuring the Auto Scaling group to use EC2 status checks as its health check type allows the ASG to automatically detect when an instance fails either a system or instance status check. Once marked unhealthy, the ASG terminates the instance and launches a replacement, providing self-healing without manual intervention. Setting the health check grace period appropriately ensures the instance is given enough time to initialize and pass status checks before being evaluated, preventing premature termination during boot or application startup.

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