How to ensure the idempotence of commodities between the commodity order system and the inventory system

In order to ensure the idempotency between the commodity order system and the inventory system, the following schemes can be adopted:

1. Prevent repeated order submission: In the commodity order system, idempotent identifiers can be used to prevent repeated order submission, such as using a unique order number or payment serial number. When a user submits an order, the product order system will first check whether the order number already exists, if it exists, it will not create an order repeatedly, if it does not exist, it will create a new order.
2. Data synchronization between the two parties: After the order is created, the product order system should synchronize the order-related information to the inventory system, including order status, product information, quantity, etc. After receiving the order information, the inventory system will check whether the current inventory is sufficient to support the delivery of the order. If the inventory is insufficient, the inventory will not be deducted, and an error message will be returned to the commodity order system. If the inventory is sufficient, the inventory is deducted and the order status information in the inventory system is updated.
3. Retry mechanism: In order to avoid the failure of order creation or synchronization failure due to network and other reasons, a retry mechanism can be implemented in the commodity order system. When the product order system fails to create or synchronize an order, it will record an error message and try again. The number of retries and the time interval can be set according to the actual situation.
4. Use distributed transactions: If the above measures cannot completely solve the idempotence problem, you can consider using distributed transactions to ensure the atomicity of order creation and inventory deduction, and ensure data consistency and reliability. However, distributed transactions may have a certain impact on the performance and scalability of the system, and specific trade-offs and optimizations need to be made in actual situations.