A seller app ACKed every order and sent nothing back

transcript

Festival night. A seller app ACKs every order. Then sends nothing back. About 2,700 orders. Not one gets packed. That's the good news.

8:40 pm. A fictional grocery seller app ships a bug. It still ACKs every confirm. But its replies never leave the outbox. 8:42. Buyer apps hear nothing. They cancel with 999, and refund. 9:25. Bug found. About 2,700 replies are stuck.

So did shops pack 2,700 orders that were already refunded? No. Not one.

Release on the ACK, and the shop packs it. For a buyer who was already refunded. But the ONDC rule says: hold the order. Release only when the buyer app acknowledges the reply.

Now it's 9:25. Do you send all 2,700 replies? No. The buyer apps cancelled long ago. Check each order's age. Past the window? Cancel with 998.

Every request got an ACK. It looked healthy from inside. So alert on confirms acknowledged with no reply sent.

Full breakdown in the lecture.