[gregw2]

I recall this hitting our startup’s various MySQL Linux servers in 2012.

They were slow/maxed out for a while till we figured it out. The DBA rebooted a few but didn’t know why and it kept cropping up on others; I drilled into root cause with some google-fu.

Not mentioned in the article is that I think this issue occurred again in 2015. I don’t recall if it hit us because we hadn’t patched/upgraded some servers since 2012 (!) and had just relied on resetting the clock/rebooting, or there were more Linux bugs (see LWN below).

Good technical writeup from Linux weekly news: https://lwn.net/Articles/504744/

And more on Linux patching in 2015: https://lwn.net/Articles/648313/

IANA canonical list of leap seconds: https://data.iana.org/time-zones/tzdb-2018a/leap-seconds.lis...