5 ms·

Details worth highlighting.. They recommend chrony over ntpd, which makes particular sense given that chrony is designed to work well on virtual machine. They a

Details worth highlighting.. They recommend chrony over ntpd, which makes particular sense given that chrony is designed to work well on virtual machine. They are doing leap second smearing like Google does internally. They don't say anything about what sort of accuracy you can expect but if the clock source is truly local it could be very good. It's kinda neat they're using a link local address.

ams6110 9y ago
What is leap second smearing? Spreading it out over some other period, vs. a sudden jump of one second?
- irhd 9y ago
  > Spreading it out over some other period Yes. They make a second last slightly long for some time period.
  - deleted 9y ago
    [deleted]
  - zaxomi 9y ago
    Or shorter... Leap seconds can be negative.
    - duskwuff 9y ago
      Theoretically, yes, but it's never happened since leap seconds were established in 1972, and it seems very unlikely to happen for quite some time. Chances are that a lot of software doesn't actually support negative leap seconds at all.
- sharth 9y ago
  https://developers.google.com/time/smear https://developers.google.com/time/smear
  - alpb 9y ago
    Relevant : https://cloudplatform.googleblog.com/2016/11/making-every-leap-second-count-with-our-new-public-NTP-servers.html https://cloudplatform.googleblog.com/2016/11/making-every-le... https://cloudplatform.googleblog.com/2015/05/Got-a-second-A-leap-second-that-is-Be-ready-for-June-30th.html https://cloudplatform.googleblog.com/2015/05/Got-a-second-A-... https://cloud.google.com/spanner/docs/true-time-external-consistency https://cloud.google.com/spanner/docs/true-time-external-con...
- kuschkufan 9y ago
  Would be interesting to use smearing for daylights saving time too. Make the hour twice as long when changing to winter and only take half the time when changing to summer. In some scenarios handling DST might not be necessary then! It wouldn't work for a tv schedule though, since what is broadcasted still uses actual time. ;)
deleted 9y ago
[deleted]
a012 9y ago
I setup a local chronyd server on AWS for long time, it's good that now I can use AWS local instead.

ams6110 9y ago

What is leap second smearing? Spreading it out over some other period, vs. a sudden jump of one second?

irhd 9y ago
> Spreading it out over some other period Yes. They make a second last slightly long for some time period.
- deleted 9y ago
  [deleted]
- zaxomi 9y ago
  Or shorter... Leap seconds can be negative.
  - duskwuff 9y ago
    Theoretically, yes, but it's never happened since leap seconds were established in 1972, and it seems very unlikely to happen for quite some time. Chances are that a lot of software doesn't actually support negative leap seconds at all.
sharth 9y ago
https://developers.google.com/time/smear https://developers.google.com/time/smear
- alpb 9y ago
  Relevant : https://cloudplatform.googleblog.com/2016/11/making-every-leap-second-count-with-our-new-public-NTP-servers.html https://cloudplatform.googleblog.com/2016/11/making-every-le... https://cloudplatform.googleblog.com/2015/05/Got-a-second-A-leap-second-that-is-Be-ready-for-June-30th.html https://cloudplatform.googleblog.com/2015/05/Got-a-second-A-... https://cloud.google.com/spanner/docs/true-time-external-consistency https://cloud.google.com/spanner/docs/true-time-external-con...
kuschkufan 9y ago
Would be interesting to use smearing for daylights saving time too. Make the hour twice as long when changing to winter and only take half the time when changing to summer. In some scenarios handling DST might not be necessary then! It wouldn't work for a tv schedule though, since what is broadcasted still uses actual time. ;)

deleted 9y ago

[deleted]

a012 9y ago

I setup a local chronyd server on AWS for long time, it's good that now I can use AWS local instead.