3 ms·
That is an insane amount of state for auth dns servers to maintain. “Pushing” the message out that the record has changed would also prove tricky to implement
by topranks 6y ago
That is an insane amount of state for auth dns servers to maintain.
“Pushing” the message out that the record has changed would also prove tricky to implement I’d say.
- avidiax 6y agoWorst case, 2^32 bits is 500MB. If you think that you'll get less than 134 million distinct queries, a simple list or a sparse array may be better. Obviously you need one of these bitmaps for every change domain (i.e. 1 per zone, or 1 per A/AAAA/CNAME record set, operator choice), and you need to clear it every (extended) TTL. So a CDN with 100,000 dynamic IP records might split themselves into 1,000 change domains of 100 records each, have a 1 hour TTL (expiry's staggered), and use 500GB ram to do this.
- znpy 6y agoso that also means that the client has to be kept connected to the dns server ? if so, that's a nice spot for user tracking. if not, how do you push data to clients behind a nat, without a stateful and persistant tcp connection? for most dns queries udp is sufficient (although sometimes tcp is necessary). 500GB ram for 100k records seems quite a lot btw.