Q64 — AWS DVA-C02 Ch.1

Question 64 of 100 | ← Chapter 1

A company uses AWS CloudFormation templates to manage infrastructure for its applications across development, pre-production, and production environments. The company needs to scale to meet growing customer demand. A developer must upgrade an Amazon RDS DB instance type to a larger instance. The developer deployed a CloudFormation stack update in the pre-production environment to change the instance size. The developer notices the stack is in UPDATE_ROLLBACK_FAILED state. What is the cause of this issue?

• A. The new instance type specified in the CloudFormation template is invalid.
• B. The database was manually deleted or modified outside of the CloudFormation stack. ✓
• C. The CloudFormation template contains a syntax error.
• D. The developer lacks sufficient IAM permissions to provision the specified instance type.

Correct Answer: B. The database was manually deleted or modified outside of the CloudFormation stack.

Explanation

Option A: An invalid instance type would typically cause the update to fail with a specific error, not result in UPDATE_ROLLBACK_FAILED. Option B: When a CloudFormation stack update fails and attempts rollback, manual deletion or modification of resources outside CloudFormation can prevent successful rollback — leading to UPDATE_ROLLBACK_FAILED. Option C: Syntax errors usually produce clear parsing errors, not UPDATE_ROLLBACK_FAILED. Option D: Insufficient IAM permissions would yield permission-related errors, not UPDATE_ROLLBACK_FAILED. Therefore, option B is the most likely cause, as external modification or deletion of stack resources during update is a common root cause of UPDATE_ROLLBACK_FAILED.