> Because everyone (and their dog) comes up with that as a solution. > They all set it to run at the top of the hour. Then at the top of > the hour, NTP servers get hammered by by all the little single > requests that the admin won't notice. think of it as the network > equivalent of the death by a thousand cuts.
Lest anyone think otherwise, this is not hypothetical. I have a nontrivial amount of data collected that shows a big hump at the top of the hour (peaking at well over twice the well-distributed background load), with a smaller spike at the half-hour, smaller but still substantial spikes every five minutes, and a pattern with small but unmistakeable spikes every minute on the minute. You can find the picture (aggregate of data collected from 2009-10-01 00:00:00 through 2009-10-13 23:59:50 - my sampling granularity is ten seconds) at ftp.rodents-montreal.org:/mouse/misc/ntp.10sec.gif if you're curious. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML [email protected] / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
