Когда использовать
Preserve order and inventory integrity in a transactional backend.
Решения для реализации
- Validate current stock inside the transaction and commit order plus stock changes atomically.
- Bind each unique idempotency key to a canonical payload hash and reject different-payload reuse.
- Parameterize values, allowlist sort keys and enforce quantity/body limits.
- Do not hold a transaction open across external payment network requests.
Как проверить результат
- Only one order wins the last unit of stock.
- An exact replay returns its original order.
- An invalid line rolls back every decrement.