SOA-C02 Question 135
Single answerA SysOps Administrator is managing an AWS CloudFormation stack that provisions a web application. After deploying the stack, the administrator notices that one of the resources, an Amazon RDS instance, failed to create due to a misconfigured parameter. The administrator updates the parameter in the CloudFormation template and attempts to re-deploy the stack, but the operation fails with a 'ROLLBACK_COMPLETE' status. What action should the administrator take to successfully update the stack?
- A
Update the stack with the corrected template by using the 'Update Stack' action.
- B
Delete the stack and create a new one with the updated template.
- C
Use the 'Continue Rollback' action to proceed with the stack rollback and then re-apply the updated template.
- D
Set the stack to the 'UPDATE_ROLLBACK_COMPLETE' state using the AWS CLI, then update the stack with the corrected template.
Show answer and explanation
Correct answer: D
Explanation
When a CloudFormation stack is in the 'ROLLBACK_COMPLETE' status, it cannot be directly updated. To recover, the administrator must set the stack to the 'UPDATE_ROLLBACK_COMPLETE' status using the AWS CLI. This action transitions the stack to a state that allows updates to be applied with the corrected template. This approach ensures the existing resources are preserved, and the update process can proceed without requiring the stack to be deleted and recreated.
- A. Incorrect.
This option is incorrect because the 'Update Stack' action cannot be used directly on a stack in the 'ROLLBACK_COMPLETE' status. The stack must first be transitioned to a recoverable state.
- B. Incorrect.
This option is possible but not recommended, as deleting the stack and creating a new one would result in the loss of any successfully created resources and requires starting from scratch.
- C. Incorrect.
This option is incorrect because 'Continue Rollback' is used during an in-progress rollback, not after the stack has reached the 'ROLLBACK_COMPLETE' status.
- D. Correct.
This is the correct option. The AWS CLI allows the administrator to set the stack status to 'UPDATE_ROLLBACK_COMPLETE', making the stack eligible for updates with the corrected template.