[CentOS] leap second and Centos

Fri Mar 6 20:26:27 UTC 2015
m.roth at 5-cent.us <m.roth at 5-cent.us>

Les Mikesell wrote:
> On Fri, Mar 6, 2015 at 1:50 PM,  <m.roth at 5-cent.us> wrote:
>>>
>>> I don't think I need to 'prove' that computer programs do repeatable
>>> things.  I just want to know the version numbers that need to be
>>> installed - something relatively easy to check.
>> <snip>
>> Two other thoughts: first, that it worked perfectly fine the last leap
>> second, and second, that ntpd, according to the manpage, can and will
>> adjust for seconds of difference with no problem at all, since that's
>> it's job.
>
> Errr, no. It did _not_ work fine in the last leap second.  If you run
> threaded applications (including, but not exclusively, java) or
> applications that called usleep the kernel would spin with 100% CPU
> use until you reset the date with some means other than ntp.   How
> could you have missed that:
> http://www.wired.com/2012/07/leap-second-bug-wreaks-havoc-with-java-linux/.
>
> Every other sysadmin in the world got calls in the middle of the night
> to fix their servers.

Ah, the system was fine, it was java that failed. And we've got a few
tomcat apps... but IIRC, we fixed them the next day - we're "tier 3", and
so "not critical", and could do that.

         mark