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> DNS caching has become next to useless. Another example of the Internet routing around damage. The DNS caching design dates back to the 1980s when it made pe
by antonvs 4y ago
> DNS caching has become next to useless.
Another example of the Internet routing around damage. The DNS caching design dates back to the 1980s when it made perfect sense. It no longer does.
- blueflow 4y agoIt made as much sense as it does now, but differently from back then, people today neglect the performance and reliability impact it has.
- sofixa 4y agoNot really, because infrastructure is much more dynamic today. Maybe if your IPs never changed long TTLs are OK, but when you're running behind a cloud load balancer, with changing IPs and failover to different regions/providers, low TTLs make more sense.
- blueflow 4y agoIts understandable that you need to change your routing dynamically, but DNS is not the right tool for that.
- solatic 4y agoAWS Route53 charges per-query. At scale, using longer TTLs, if clients respect the longer TTLs, has a measurable impact on your bill.
- dexterdog 4y agoThat's why you use aliases as much as possible since they are not charged.
- jesprenj 4y agoIt makes a lot of sense, if we think about how the protocol works. Without caching, I assume every client would send every query in it's entirety to the root server, right? Since a single zone can have multiple labels ({abc.def}.ghi.example - abc.def is a NAME in ghi.example), the server needs to receive the entire requested name in order to properly respond (yeah, root queries usualy optimize this, because all NAMEs there are one label long).