Actually — yes.
Early Saturday morning Japan time most of the servers in the company where I work now started to act. CPU usage spiked to 100-200% while no load was actually hitting the servers.
Mysql on restart used again insane amount of CPU. At the same time, servers were quite responsive and acting like normal.
After some time later reports started to appear in Google search… Reports were talking about … leap second
At the mid-night GMT time on Jun 30, 2012 extra second was added — leap second. NTP supposed to have been picked up that small change, but it did not. Most of the Linux servers’ CPUs went into timeless cycle: check flag (‘leap second’ flag in NTP protocol), set flag, check flag, reset flag …
The funniest thing about all this story is sequence of commands you’d have to run to fix the issue:
ntp stop ntpdate ntp.pool.org ntp start
Or even this (!!) :
ntp stop date -s "`date`" ntp start