Question 140
A production readiness review reports the following problem, the decisive constraint is: An application release must stop automatically when the error rate rises above a predefined threshold. What is the most defensible implementation decision?
Explanation
Correct Answer
Bind deployment lifecycle alarms to rollback and bake-period monitoring. Metric-gated rollback prevents continuing a demonstrably unhealthy release.
Incorrect Answers
For the separate situation A Lambda function update must be exposed to 10% of users before broader rollout, Use CodeDeploy Lambda canary deployment with an alias and CloudWatch rollback alarm could be useful. Traffic shifting and alarm hooks limit impact of a faulty function revision.
Although Configure ECS rolling deployment minimum healthy percent and maximum percent can be valid when A container platform must deploy a new image without terminating all old tasks simultaneously, it targets a different technical condition. Rolling task replacement maintains defined healthy capacity during deployments.
Adopt a blue-green deployment using separate target groups and health-based traffic shifting would address a different requirement: A web fleet update must allow immediate routing back to the previous version after failed health checks. Two independently serving versions permit fast traffic reversal.