5 ms·
I 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
by daurnimator 9y ago
I 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 agoThe datacenter I use does: http://www.he.net/adm/ntp.html http://www.he.net/adm/ntp.html
- jsjohnst 9y agoAs one example, Rackspace doesn’t (they upstream from pool) for all their data centers. Source: recently asked them this.