Hacker News new | ask | show | jobs
by andrewaylett 1062 days ago
That definitely helps things to work, but it makes it very much more difficult to work out why things might not be working.

Not least because an unexpected cache can lead to things looking like they're working when they're actually broken at source, as well as things looking like they're still broken when you've actually fixed them at source already.
1 comments
Dylan16807 1062 days ago
"I didn't know that cache existed" isn't because of the difficulty of invalidating the right items, though.

And the occasional cache that keeps things forever is so extra broken that it's not doing that because cache invalidation is hard, it's either a supreme misunderstanding or it's incompetence.

link
lanstin 1062 days ago
Sadly reboot the VM is still a valid step in debugging DNS, while you google "clear cache for this type of client resolver"

Also, the dreaded caching of negative results/authoritative no such domain just before you get the new domain working properly.

link
zhengyi13 1062 days ago
> And the occasional cache that keeps things forever is so extra broken that it's not doing that because cache invalidation is hard, it's either a supreme misunderstanding or it's incompetence.

Working in phone technical support in the early 2000s, I encountered first in CF6 and then at least one J2EE implementation (Websphere, maybe?) where the $^&#ing default was to cache DNS results forever.

The behavior was borderline undocumented, and the setting to fix it was even less well documented. It's like they wanted DNS to not be a thing.

link