alt Hacker NewsYou have to cache, cloudflare doesn't know all the records ahead of time, they have to do recursive lookups to the authoritative servers that own the records and that is only good for the period of the TTL of the record. There is no "global" DNS record database or something like that.
>that is only good for the period of the TTL of the record.
Not really, TTLs are often short, but IPs might not change for years.
You can probably generate your own TTL, at scale, and avoid many DNS requests.