[172708] in North American Network Operators' Group
Re: Erroneous Leap Second Introduced at 2014-06-30 23:59:59 UTC
daemon@ATHENA.MIT.EDU (Tim Heckman)
Tue Jul 1 22:19:47 2014
X-Original-To: nanog@nanog.org
In-Reply-To: <20140701193542.GA30902@puck.nether.net>
Date: Tue, 1 Jul 2014 19:19:37 -0700
From: Tim Heckman <t@heckman.io>
To: "Majdi S. Abbas" <msa@latt.net>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
On Tue, Jul 1, 2014 at 12:35 PM, Majdi S. Abbas <msa@latt.net> wrote:
> On Tue, Jul 01, 2014 at 12:20:12PM -0700, Tim Heckman wrote:
>> Our systems all have loopstats and peerstats logging enabled. I have
>> those log files available if interested. However, when I searched over
>> the files I wasn't able to find anything that seemed to indicate this
>> was the peer who told the system to introduce a leap second. That
>> said, I might just not know what to look for in the logs.
>
> Look at the status word in peerstats; if the high bit is
> set, that's your huckleberry.
>
> See: http://www.eecis.udel.edu/~mills/ntp/html/decode.html
I've taken a look at all of the peerstats available for this host, and
surprisingly none of them are showing code 09 (leap_armed). I'm also
fairly certain that I know when some of my systems armed the leap
second (within a 60-120s window) based on our monitoring. Around those
times everything seems normal according to peerstats. Looking at
I am running Ubuntu 10.04 on this box, which is ntp v4.2.4p8. I'll
need to looking to see if the printing of this flag was added later;
otherwise, it would seem some of my systems picked up a phantom leap
second from an unknown source with one of them actually executing it.
Thanks for the decoder ring. My Google-fu wasn't hitting the right keywords.
>> Correct, I was hoping to determine which peer it was so I can reach
>> out to them to make sure this doesn't bleed in to the pool at the end
>> of the year. I was also more-or-less curious how wide-spread of an
>> issue this was, but I'm starting to think I may have been the only
>> person to catch it in the act. :)
>
> You might want to upgrade to current 4.2.7 development code,
> wherein a majority rule is used to qualify the leap indicator.
We're going to be doing some system refreshes coming soon, so that may
be something we'll need to look at. I didn't realize this was
happening as part of the 4.2.7 development branch. Definitely an
interesting feature, especially after this. :p
> Cheers,
>
> --msa
Thanks again, Majdi.
Cheers!
-Tim
