I’ve just got the Bulletin C from the IERS, and with good news: there won’t be a leap second in December. The next leapocalypse will have to wait at least until June 2014.

For your reference, here’s the full bulletin:

     INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS) 

SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE

SERVICE DE LA ROTATION TERRESTRE
OBSERVATOIRE DE PARIS
61, Av. de l'Observatoire 75014 PARIS (France)
Tel.      : 33 (0) 1 40 51 22 29
FAX       : 33 (0) 1 40 51 22 91
Internet  : services.iers@obspm.fr

                                             Paris, 8 July 2013

                                             Bulletin C 46

                                             To authorities responsible
                                             for the measurement and 
                                             distribution of time             

                          INFORMATION ON UTC - TAI

 NO leap second will be introduced at the end of December 2013.
 The difference between Coordinated Universal Time UTC and the 
 International Atomic Time TAI is :		

     from 2012 July 1, 0h UTC, until further notice : UTC-TAI = -35 s

 Leap seconds can be introduced in UTC at the end of the months of December 
 or June,  depending on the evolution of UT1-TAI. Bulletin C is mailed every  
 six months, either to announce a time step in UTC, or to confirm that there 
 will be no time step at the next possible date.
                                            Daniel GAMBIS
                                            Director			
                                            Earth Orientation Center of IERS
					    Observatoire de Paris, France
__________________________________________

I still remember very well the first (and only, for now) time I held a seminar for my colleagues in Opera: “NTP, a misunderstood protocol” in February 2011. Now fast forward to 2012. We had one leapocalypse between June and July, one bogus leap second one month later, and a bit of disaster about one week ago: nearly two years have passed since I held that seminar, and NTP is still a misunderstood protocol. … Continue reading →

I think it's quite ironic that someone considers me an NTP guru. Because I am not. I am just a sysadmin who, once upon a time, had an NTP service to rebuild and wanted to get it right.

What happened then is: instead of doing what a bunch of the sysadmins out there did and still do (use the default configurations of the OS, or trust one of the misleading sources you can find with google), I downloaded the RFC and read most of it. And then, I downloaded the (then) two Sun blueprints about NTP and read them too. Only when I understood how a good architecture ought to be, I started with the design and the implementation.

I must say that I didn't get the architecture right the first time, but at least I learnt what was wrong with it. I kept studying on the subject, doing experiments, and discussing with people who had a much better understanding of the internals (how ntpd really works) and… externals 🙂 (all the electronics engineering theory behind the algorithms used in ntpd). And I ended up building a (hopefully) decent NTP infrastructure for all the employers I worked for.

As you see, I am just a person who tackled a problem more seriously than the average. That was enough to stand out compared to "the mass" and make me look like a guru… not being it!

When Cosimo asked for a photo of mine for his talk at Velocity Europe 2012, and he was going to talk about last July's leapocalypse, I spent one hour with my wife to get some nice photos with the right amount of irony in them. In the end, we selected two photos and sent them to Cosimo.

Of course, Cosimo chose for his presentation the one I liked less, that's why I'm doing justice to my favourite by publishing it here:

If there is as much irony as clocks in the photos, the goal is achieved 😉

It's this morning news that there is still a number of servers in the NTP pool that are advertising a bogus leap second. If you are using the NTP pool, you may want to check your configurations and ensure you're not getting a bogus leap advertisment. If you are, well: change your configurations with some good servers, and restart ntpd.

Good luck

…my friend and ex-colleague Giovanni pointed me to an interesting post regarding an interesting Oracle crash in the occasion of the leap second we had in 2008. Enjoy the post.

Summary

We'll have a leap second insertion at the end of June this year. My tests and other evidence shows that the Linux kernel in Debian Squeeze (but possibly in newer versions of the Kernel, too, I didn't check the sources) doesn't handle the leap second in the best way, and steps back one second around midnight between June 30th and July 1st. This is a big pain in the… grass 🙂 for time-sensitive applications (e.g.: clusters), or those that rely on a monotonic clock (usually RDBMSs; e.g. older versions of Oracle crashed badly, dunno about newer).

I am trying to find feasible workarounds for this, and I'll keep you posted. … Continue reading →