[LEAPSECS] [time-nuts] Leap Quirks

[Rob Seaman]

Tony Finch wrote:


> On Mon, 5 Jan 2009, Rob Seaman wrote:

>>

>> The recent leap second passed (yet again) with no major issues.

>

> Wrong.

>

> Loads of Oracle RAC servers crashed because of a bug triggered by the

> clock going backwards.

>

> http://www.merit.edu/mail.archives/nanog/msg13857.html


Where the statement is:

	"I had a couple of Oracle servers (Solaris 10) reboot a couple of  
minutes just before the leap second. All my other Solaris 10 boxes  
appear to have stayed up fine."

The phrasing doesn't even make it clear that this was causally  
connected to the leap second.  I assume that later messages in the  
thread clarify this.

It might help to standardize a definition of "major issue".  Our group  
uses JIRA to track issues.  We have two levels above major issue,  
namely "critical" and "blocker".  Leap seconds are clearly not a  
blocker, since we have moved past this one just like the previous  
ones.  Given that the current standard is viable for hundreds of  
years, it is also hard to rate them as critical.


> Many time dissemination systems got it wrong, as usual.

>

> I wonder why OS vendors don't ship ntpd preconfigured with a  

> leapseconds

> table that is updated as part of the OS's normal patching process. I  

> hope

> that would reduce the amount of manual maintenance required for  

> stratum 1

> servers and increase the reliability of NTP's leap second handling.


Sound like good ideas.  Fix the bug.  Improve the processes.


> Obviously leap seconds are so important that we can't do without them,

> but so unimportant that it doesn't matter that we can't get them to

> work properly.


Stabilizing civil time with respect to the slowly evolving diurnal  
rate is important.  You say so yourself:

	http://catless.ncl.ac.uk/Risks/25.50.html#subj1

If leap seconds are truly failing to satisfy a requirement for  
ignorability, we have mentioned many different possibilities over the  
years for stabilizing civil timekeeping.

The ITU proposal to simply ignore the whole thing for a thousand years  
is not one of these.

Rob