5 ms·
Windows Update. To reboot a server, you need to take it out of production. With a TTL of 5 minutes, it can take an hour for (nearly) all users to stop using th
by rebelde 5y ago
Windows Update. To reboot a server, you need to take it out of production. With a TTL of 5 minutes, it can take an hour for (nearly) all users to stop using that server.
- yjftsjthsd-h 5y agoSorry - why would a 5m TTL take an hour to stop using? Shouldn't it be 5 minutes?
- Twirrim 5y agoIf things behaved nicely, yes. There's all sorts of weird DNS caching behaviour out there. It's not unusual to find folks with DNS servers / clients that are caching records for 1 hour+, and then of course there's people running super old versions of Java that used to cache DNS forever by default (before JDK 6). There's a very clear set of user that seem to cache for 10-15 minutes, regardless of any DNS TTL.
- marcosdumay 5y agoYou can't fix systems that ignore your TTL by specifying lower TTL values.
- Twirrim 5y agoSure. My general approach is to use lower TTL values (~ 5 minutes) and just accept that if people do dumb things, they just have to put up with things randomly breaking unexpected.
- EricE 5y agoGood grief- you do not need to reboot the server; just flush the cache https://www.dnsstuff.com/clear-flush-dns-server-cache-windows https://www.dnsstuff.com/clear-flush-dns-server-cache-window...
- majewsky 5y agoThey mean they're rebooting the server having the IP that's entered in DNS, not rebooting the client consuming that service.