SOA-C03 practice question: Troubleshooting deployments (2 of 2)

Deployment, Provisioning, and Automation A free question from our original SOA-C03 practice exam. Try it, then open the answer to see why each option is right or wrong.

An esports league's CloudFormation stack update failed, and the stack then entered UPDATE_ROLLBACK_FAILED. The events show that the rollback could not restore an Amazon SQS queue because an engineer had deleted the queue manually earlier that day. The queue is no longer needed. The other stack resources, including a DynamoDB table with live data, must be kept, and the team wants the stack updatable again. What should a CloudOps engineer do?

Choose one answer.

A. Continue the update rollback and skip the queue's logical ID so that the rollback can finish.
B. Delete the stack and create it again from the last working template, then restore the table's data from a backup.
C. Cancel the stack update so that CloudFormation stops the rollback and returns the stack to UPDATE_COMPLETE.
D. Run drift detection on the stack so that CloudFormation records the deleted queue as drifted and finishes the rollback.

Show the answer and explanation

Answer: A

A. Right: Correct. Continue update rollback retries the rollback, and resources to skip lets CloudFormation treat resources that cannot be rolled back as done. The stack reaches UPDATE_ROLLBACK_COMPLETE and can be updated again. Learn more: Continue rolling back an update (opens in a new tab)
B. Wrong: Deleting the stack removes every resource in it, including the live table unless it is retained. This is far more disruptive than needed. Learn more: Troubleshooting CloudFormation (opens in a new tab)
C. Wrong: Cancel update works only while a stack is in UPDATE_IN_PROGRESS. It cannot be used on a stack in UPDATE_ROLLBACK_FAILED. Learn more: Cancel a stack update (opens in a new tab)
D. Wrong: Drift detection reports differences between the template and live resources. It does not change the stack's state or complete a failed rollback. Learn more: Detect unmanaged configuration changes to stacks and resources with drift detection (opens in a new tab)

Explanation

UPDATE_ROLLBACK_FAILED usually means a resource changed outside CloudFormation and cannot be returned to its old state. ContinueUpdateRollback retries the rollback, and its resources-to-skip option handles resources that no longer exist. The stack then returns to a stable state without touching the other resources.

SOA-C03 practice question: Troubleshooting deployments (2 of 2)

Explanation

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