[181701] in North American Network Operators' Group
Re: leap second outage
daemon@ATHENA.MIT.EDU (Mikael Abrahamsson)
Wed Jul 1 01:38:53 2015
X-Original-To: nanog@nanog.org
Date: Wed, 1 Jul 2015 07:38:49 +0200 (CEST)
From: Mikael Abrahamsson <swmike@swm.pp.se>
To: Jean-Francois Mezei <jfmezei_nanog@vaxination.ca>
In-Reply-To: <559375B7.4010908@vaxination.ca>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
On Wed, 1 Jul 2015, Jean-Francois Mezei wrote:
> However, in systems that expect tightly synchronized clocks, they would
> want all the nodes to make the NTP adjustement at the same time.
This is both an operating system and application problem.
http://infiniteundo.com/post/25326999628/falsehoods-programmers-believe-about-time
http://infiniteundo.com/post/25509354022/more-falsehoods-programmers-believe-about-time
This is similar to the jiffycounter wrapping, since this doesn't happen
that often, it's not commonly tested for. Good way is to start the jiffy
counter so it wraps after 10 minutes of uptime. That way you'll run into
any bugs quickly. Either we should abolish the leap second or we should
make leap second adjustments (back and forth) on a monthly basis to
exercise the code.
This is a hard sell though...
--
Mikael Abrahamsson email: swmike@swm.pp.se
