Facebook switches to new timekeeping service (2020)
spectrum.ieee.org
spectrum.ieee.org
I submitted this because I wasn't aware that Facebook had switching to leap-second smearing, which previously prevented me from using Facebook's time servers. Why use this over Google's? For those of us not on the west coast, Facebook's time.facebook.com and friends has a round-trip delay of ~2.5ms (on a dedicated fiber uplink, so no docsis overhead) and more importantly, a jitter of less than 0.025ms, whereas Google's best round-trip delay (for me) is at ~30ms and is subject to a more variable jitter given all the hops it takes to reach it. You shouldn't (read: can't) mix smearing and non-smearing time servers, so using them even as an alternative NTP node wasn't an option in the past.
It doesn't really make a difference for NTP consumers, but I also wasn't aware that Facebook had made the switch to chrony - also mentioned in the article.
(Sidenote: time.apple.com has servers all over the US w/ some really low latencies for me, but no one seems to know for a fact if they smear leap seconds or not, which to translates to they almost certainly don't. Can any Apple insiders on HN answer that question?)
[0]: https://engineering.fb.com/2021/08/11/open-source/time-appli...