5 / 5 Invalidation & Cache Consistency

One POST Two Origins

A shared cache forwards this exchange:

POST /orders/8812 HTTP/1.1
Host: shop.example.com

HTTP/1.1 303 See Other
Location: https://cdn.example.net/receipts/8812.pdf
Content-Location: /orders/8812

Select every statement that RFC 9111 supports. More than one is correct.

A

Had the POST returned 500, the cache would still be required to invalidate the target URI

B

No invalidation is required, because 303 is not a 2xx status code

C

Invalidating may mean marking the stored response as needing mandatory validation rather than deleting it outright

D

The cache must invalidate its stored responses for https://shop.example.com/orders/8812

E

The cache must not invalidate https://cdn.example.net/receipts/8812.pdf, because that origin differs from the target URI's origin

F

After this, no cache anywhere still holds the pre-POST representation of the order