On 21 October 2016 at 18:12, Jean-Francois Mezei <jfmezei_na...@vaxination.ca> wrote: > On 2016-10-21 18:45, david raistrick wrote: > >> switch too..). setting TTLs that make sense for a design that supports >> change is also easy. > > Cuts both ways. Had Twitter had TTLs of say 7 days, vast majority > wouldn't notice an outage of a few hours because their local cache wa > still valid.
In practice TTLs tend to be ignored on the public internet. In past research I've been involved with browser[0] behavior was effectively random despite the TTL set. [0] more specifically, the chain of DNS resolution and caching down to the browser. -- Eitan Adler
