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Argh! I wish the NTP servers were usable from outside of AWS. Outside of North America and Europe, there aren't as many public NTP servers as there should be.
by CaliforniaKarl 9y ago
Argh! I wish the NTP servers were usable from outside of AWS.
Outside of North America and Europe, there aren't as many public NTP servers as there should be. For example, according to http://www.pool.ntp.org/zone/south-america http://www.pool.ntp.org/zone/south-america, South America has less than 50 NTP servers.
It would be awesome if the large, widely-distributed providers (not just AWS with CloudFront, but also Akami, Cloudflare, etc.) provided public, Stratum-1 NTP servers at their POPs.
- ehPReth 9y agoGoogle hosts some: https://developers.google.com/time/ https://developers.google.com/time/
- jlgaddis 9y agoNote that they smear time, though (WRT leap seconds), as do Amazon. You generally do not want to mix "smearing" and "non-smearing" time servers.
- mark-r 9y agoYou probably don't want to mix time servers that use a different algorithm for smearing, either.
- aunty_helen 9y agoInteresting point, we're looking at implementing this new ntp server. Wanted to know a bit more about the risks of mixing leap second algos. Is there any more info / links you can give on the subject?
- LeoPanthera 9y agotime.windows.com, time.apple.com, and time1.google.com are all publicly accessible. Apple's one is also available at time.asia.apple.com and time.euro.apple.com
- deleted 9y ago[deleted]
- 1010011010 9y agowindows and apple tend to keep terribly inconsistent time, though, and windows time goes nutso at leap smears.
- LeoPanthera 9y agoDo you have a citation for this? I've been monitoring NTP servers for years and Apple's are among the closest to my GPS reference.
- dboreham 9y agoHmm...our data center (bare iron, not cloud) has always provided NTP servers. I assumed this was standard.
- tedivm 9y agoAnyone can provide an NTP server, but that's much different from having an atomic clock powered NTP server. The servers your datacenter provide are probably clients of other NTP servers, so the quality and availability of NTP servers near your datacenter is still really important.
- daurnimator 9y agoI would assume a datacentre would put a GPS somewhere to provide time to an NTP server. It's quite cheap, easy to do, and a useful value-add for their customers; and it's something that can only can be done by someone with physical (and likely roof) access.
- wpietri 9y agoAnd I would add for the crowd that one can easily check what sort of NTP server is on offer. NTP tracks the "stratum" of a server, which is how far the server is from an authoritative time source: https://en.wikipedia.org/wiki/Network_Time_Protocol#Clock_strata https://en.wikipedia.org/wiki/Network_Time_Protocol#Clock_st... If you're using ntpd, you can check it like this: $ ntpq ntpq> peer remote refid st t when poll reach delay offset jitter ============================================================================== *y.ns.gin.ntt.ne 249.224.99.213 2 u 815 1024 377 1.230 -4.148 1.825 +hadb2.smatwebde 209.51.161.238 2 u 809 1024 377 49.672 -2.073 3.869 +six0.ntp3.mattn 128.227.205.3 2 u 409 1024 377 63.721 -4.328 2.669 -hadb1.smatwebde 45.79.187.10 3 u 808 1024 377 49.767 -6.600 2.927 These are 4 servers out of the NTP pool; 3 are stratum 2 and one is stratum 3. The * means it has selected the first, the + means it likes the next 2, and the - means it has discarded the last one.
- Veratyr 9y ago