Exam AWS Certified SysOps Administrator - Associate topic 1 question 164 discussion

Ans is B. It will delete all the resources in the stack but stack deletion will be manual.

By default, when a resource creation fails during the creation of a CloudFormation stack, CloudFormation will roll back the stack to its previous state, undoing any changes made to the stack. Therefore, the answer is B. CloudFormation will roll back the stack but will not delete the stack. This allows the administrator to troubleshoot the issue that caused the failure and attempt to create the stack again.

A is the answer

Answer is A and ChatGPT agrees: By default, when a CloudFormation stack creation fails for any resource, CloudFormation rolls back the entire stack. This means that CloudFormation will attempt to undo all the changes it has made so far and will delete any resources that were successfully created (like the EC2 instances and the ELB in your scenario). The stack itself will also be deleted.

CloudFormation by default delete everything after the rollback.

CloudFormation by default delete everything after the rollback.

B for sure!

A. CloudFormation will roll back the stack and delete the stack. Explanation: When a stack creation fails, AWS CloudFormation automatically rolls back all resources that were created up to the point of failure. This behavior is intended to ensure that partial and potentially unstable stacks are not left in your account. This rollback operation includes deleting any resources that were successfully created before the failure occurred. This means that both the EC2 instances and the Elastic Load Balancer will be deleted since the creation of the DB instance failed. This automatic rollback is the default behavior unless you explicitly specify otherwise by disabling rollback.

CloudFormation will not delete the stack by default. If you want CloudFormation to delete the stack if it rolls back, you need to specify the DeletionPolicy property in the template. The DeletionPolicy property can have three values: Delete - CloudFormation will delete the stack and all of its resources. Retain - CloudFormation will not delete the stack or any of its resources. Snapshot - CloudFormation will create a snapshot of the DB instance and then delete the stack. In this case, the default behavior is to roll back the stack and not delete the stack.

CloudFormation will delete the resources it created during the stack creation attempt but it will not remove the stack record itself. This allows you to review the stack events and troubleshoot the reason for failure. I hope this clarifies the matter.

Second quote blurs the distinction between A and B, but I think answer is still B. I actually creating a stack it with a template with an intentional error (acloud.guru demo/lab file). The stack roll back out as expected and the stack did not delete itself, and I still had the stack listed under the "stacks" menu. Even though it had known error and never had a "last known stable state", I saw it listed in stacks menu, and I wasn't able to create another stack using the "TestStack stack (e.g. Error "Stack name allready exists") Don't mean to ramble on here, but sometimes the AWS exam questions and answers don't exactly match the reality in the AWS console. Facts: (*) "Roll back all stack resources" (default setting from CloudFormation create stack menu) "Specify the rollback-stack operation to roll back a stack to its last stable state." "Note: The rollback-stack operation will delete a stack if it doesn't contain a last known stable state." https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/stack-failure-options.html

I think A The rollback-stack operation will delete a stack if it doesn't contain a last known stable state. https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/stack-failure-options.html

B CloudFormation will roll back the stack in the event of a failed resource. It will not delete the stack automatically, and will instead leave it in a failed state. The user will then have the option to roll back the stack manually or continue with the stack in its failed state.

A "If the stack updates fails, CloudFormation rolls back changes to restore the stack to the last known working state." Restore the stack means deleting the new objects created during the stack.

The answer is A. Reference ....https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-whatis-howdoesitwork.html

I think is A... it will attempt to delete the stack and rolback...

B. CloudFormation will roll back the stack but will not delete the stack. In AWS CloudFormation, if the creation of a resource within a stack fails, CloudFormation will roll back the entire stack to its previous state. This means that any resources that were created successfully will be deleted, and the stack will be returned to the state it was in before the stack creation began. However, CloudFormation does not delete the stack itself in this scenario. Instead, the stack remains in a failed state, and the administrator can choose to roll back the stack or continue with the stack creation.