[CentOS] leap second and Centos

Thu Jan 15 17:23:08 UTC 2015
Jason Pyeron <jpyeron at pdinc.us>

> -----Original Message-----
> From: Akemi Yagi
> Sent: Thursday, January 15, 2015 12:05
> 
> On Thu, Jan 15, 2015 at 8:43 AM, G Galitz <geoff at galitz.org> wrote:
> >
> > Hi.
> >
> > We have another leap second coming.  Have past bugs with 
> Centos and leap
> > seconds (specifically high CPU spikes) been resolved? 
> Should we be worried?
> 
> Apparently Red Hat is well aware of the upcoming leap second:
> 
> https://access.redhat.com/solutions/1317263
> 
> Unfortunately all the related bugzilla reports are private so we
> cannot see the status.

It seems to boil down to: https://bugzilla.redhat.com/show_bug.cgi?id=479765 which is closed fixed. The private bugs are "pay attention" tickets, but some do reference KB Article "Leap Seconds in Red Hat Enterprise Linux".

A summary of Leap Seconds in Red Hat Enterprise Linux - https://access.redhat.com/articles/15145 

Issue:

6 different ways of saying "Will my system work?" .

Environment:

EL 4-7

Resolution:

For EL6 see:
* https://access.redhat.com/knowledge/solutions/154713
* https://access.redhat.com/knowledge/solutions/154793
* https://access.redhat.com/knowledge/solutions/173693
* https://access.redhat.com/knowledge/articles/199563

Otherwise if you run NTP resolution A else B

Resolution A:

NTP logging may crash EL 4/5, update your system.

EL4 see http://rhn.redhat.com/errata/RHSA-2009-1024.html
EL5 see http://rhn.redhat.com/errata/RHSA-2009-1243.html
EL6/7 not affected, but EL6 see https://access.redhat.com/site/solutions/154793 CPU usage sucks after leap second*

[*:side bar: see http://rhn.redhat.com/errata/RHBA-2012-1199.html for the patch or do something like "date $(date +someformatthatworks)"]

PPC and IA64 arches will self destruct and should not use NTP

Resolution B:

Your time will be wrong and you should be happy. A new tzdata will come out see bugs: 
EL4: https://bugzilla.redhat.com/show_bug.cgi?id=1181975
EL5: https://bugzilla.redhat.com/show_bug.cgi?id=1181933
EL6: https://bugzilla.redhat.com/show_bug.cgi?id=1180536
EL7: https://bugzilla.redhat.com/show_bug.cgi?id=1181970

Root Cause:

https://what-if.xkcd.com/26/

--
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-                                                               -
- Jason Pyeron                      PD Inc. http://www.pdinc.us -
- Principal Consultant              10 West 24th Street #100    -
- +1 (443) 269-1555 x333            Baltimore, Maryland 21218   -
-                                                               -
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
This message is copyright PD Inc, subject to license 20080407P00.