[ntp:questions] How is the BIG guys (Google. FB etc) DNS and NTP architecture

William Unruh unruh at invalid.ca
Wed Oct 21 03:47:08 UTC 2020

On 2020-10-21, CRasch Net <crasch at crasch.net> wrote:
> Facebook is now using Chrony, you can read about their implementation:
> Building a more accurate time service at Facebook scale
> https://engineering.fb.com/production-engineering/ntp-service/

Interesting. While I agree that chrony is more precise, I think that
their results for ntpd are worse than they should  be. ntpd can
certainly do better than 1ms scatter/accuracy (and chrony can do better
than 100us.There is something weird about their network paths.) About 10
years I ran a number of tests of chrony vs ntpd. and got about a fctor
of 3-10 better, not 100. Interrupt latency/clock reading for chrony gave
about 1us fluctuations.

I find this whole thing about leap second smoothing to be a real farce.
Just let the step occur instead of delivering the wrong time for hours.
Or if you want, run your clocks on TIA not UTC and make the leapsecond
conversion in the interpretation as is done for timezones. Would anyone
advise leap day smoothing every 4 years so that we do not have trouble
with our calenders?

More information about the questions mailing list