On Mar 22, 2011, at 4:59 PM, Ask Bjørn Hansen wrote: > I don't have any ideas for how to avoid this; but basically a crazy amount of > the SNTP clients sync just at the top of the hour; or close to it. > > Below is a second by second query count on one of the busier DNS servers for > pool.ntp.org. The normal load is as it is just before the top of the hour > and it drops most of the way back to that after a few minutes (and all the > way after ~15 minutes it looks like).
Yes, it seems to be common for people to set up cron jobs sync'ing once an hour, rather than once an hour + random(300) or so seconds. A tenfold increase in query rate doesn't strike me as surprising. Even a T1 or 1.5Mbs symmetric DSL/cable link should be able to handle 1000 NTP queries per second and still have most of its bandwidth left over. Regards, -- -Chuck _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
