Wholesale customer's big pre-season order fails at checkout with an error

Component: Checkout (support's guess)

From: Marcus Dell, purchasing, Harbor Hardware Supply · Received: Tue 20 Oct, 6:50 pm

Hello, we are one of your wholesale customers and every October we order our spring stock. This year we wanted to do it through the website instead of calling it in. I uploaded our whole list into the cart with the quick-order upload (about 700 different items) and pressed place order, and all I get is an error message saying something went wrong. I tried four times, the last from another computer. Our normal weekly orders of 40 or 50 items go through fine, so it is not our account or our card. Our sales rep told us there should be no limit on how many items an order can have, and next spring's full catalogue order will be well over a thousand lines. The supplier price list we are ordering from expires on Friday, so we need this working this week, or we will have to phone it in again and lose the web discount.

Thanks, Marcus

Support note (Dana K.): Reproduced with Marcus's cart contents on the staging copy: checkout fails for me too, and a trimmed copy of his cart with fewer items is placed fine. I did not find an out-of-stock item or an archived one in his list, and a payment step doesn't exist in this API (orders are invoiced later). I attached the server log for the time of his last tries (attachments/api-server.log). Marcus only ever sees the generic "Something went wrong" message.

Ask: make large orders go through, without changing how normal orders, stock and promo codes behave. If there is a limit we cannot remove, tell us what it is, but Harbor's orders (up to about 1,500 lines) must go through.

Triage (support), written up for engineering:

Symptom

Placing an order fails with a generic error for very large carts; normal weekly orders are fine.

Steps to reproduce

1. Sign in as a customer on staging and put several hundred different products in the cart (the quick-order upload does this; on staging you can also insert cart rows directly).
2. Place the order.
3. Repeat with a cart of 40 lines and compare.

Expected

The order is placed with one line per product, correct totals, stock taken for every line and the cart emptied, as for a small order.

Actual

The request fails with a server error and no order exists afterwards.