Wrap task creation in a transaction that locks the business line row (SELECT ... FOR UPDATE) so concurrent requests cannot both pass the availability check. A name is considered occupied by in-flight or retained tasks (pending through registering, finished, register_failed, canceling, rollback_pending/rolling_back/rollback_failed) and by active deployment results; it becomes reusable only after rollback or explicit cleanup releases it.
Hungerdream
ecad474785