Tech giants like Meta, Google, Amazon and Microsoft have declared war on so-called leap seconds. This insignificant measure of time serves to synchronize the time with variations in the earth’s rotation from time to time, but brings down the street of bitterness to the technology industrydestabilizing computers and causing crashes suffered by users in Spain and many other countries.
[Gran parte de Internet caída una hora: así ha sido el fallo que ha afectado a Google y otras webs]
Over the years, the Internet has become a well-oiled machine that seems to tackle everything and everyone, so it may seem unlikely that a single second too many can put it in check. Years ago leap seconds or leap seconds they are the center of a battle between detractors and defenders. It is time to settle this debate.
Representatives from around the world at the World Radiocommunication Conference in Geneva in 2015 could not agree and decided to postpone this resolution until 2023 to have more information. A few months before that date, the most important internet companies send a clear message, they want to forget about this practice and they have the support of French and American institutions.
The leap second
In 1972, the authorities that regulate the measurement of time introduced for the first time a leap second to the standard clock governed by TAI (International Atomic Time). To add that troublesome second instead of ending the day going from 23:59:59 to 00:00:00, the clock reads 23:59:60.
this trick It has been used up to 27 times since then, being a headache for the many computers that have been created over these decades and on which servers, computer programs and internet pages depend. When it is applied, it is announced by the International Service for Earth Rotation and Reference Systems and is usually applied on June 31 or December 31, but not every year.
Time on a Mac
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Advocates of this practice say it remains essential to maintain the link between human timekeeping and the sun’s natural cycle that are closely linked across the planet. This is because the Earth’s rotation time is not absolute like clocks are, and the speed at which it rotates depends on different geological events.
the movement of the poles, the production of earthquakes, tsunamis, large air masses or the melting of ice It affects the speed with which the Earth rotates on itself, sometimes speeding up and sometimes slowing down. ANDSW yes, said speed barely at the level of milliseconds.
Earth’s rotation
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Researchers have previously revealed that changes in the climate and the abrupt weather events that are taking place affect the Earth’s axis of rotation. It is very likely that this rotation, in addition to tilting, will continue to slow down, since since the origin of the planet, the speed of the Earth has been slowing down by about 6 km/h every 10 million yearsmainly due to the gravitational attraction produced by the Moon on this planet.
However, the change is so slow that critics of the leap second denounce that the measure remains in force only by tradition and criticize that, currently, that extra second causes more problems than benefits.
alarm clock on mobile
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In its statement, Meta even considers the headaches it could give a negative leap second, that is, remove it instead of adding it. A possibility that has been raised but has never been applied. The time jump would look like this from 23:59:58 to 00:00:00. “The impact of a negative leap second has never been tested on a large scale; it could have a devastating effect on software that relies on timers or schedulers,” they explain.
system crashes
Those who criticize the use of that extra second list the interruptions that this measure has already caused on the internet. Meta remembers that the social network Reddit suffered a massive crash in 2012 that prevented users from accessing the platform for 30 or 40 minutes. “The time change confused the high resolution timer (hrtimer), which caused hyperactivity in the servers and locked up the CPUs of the machines,” they say.
Also in 2017, Cloudflare saw its DNS (Domain Name System) service that associate IP addresses of networks on the internet affected. Leap second was the basis of the problem that the company itself explained at the time as follows: “The cause of the error that affected our DNS service was the belief that time cannot go back.”
Similar problems have been reported on Mozilla, Linkedin or the airline reservation service. Although bugs or crashes always end up being fixed within a few hours with the help of the developers in charge of each system, the tech giants are fed up with having to put out these fires from time to time and propose alternatives so as not to use the second one again. insert.
Alternatives
“As an industry, we run into problems every time a leap second is introduced,” Meta denounces, assuring that “it devastates the community every time it happens.” For the company that owns Facebook, Instagram and WhatsApp, the solution is simple, that the leap second becomes part of the past and will not be used again. For this technology heavyweight it is enough to use the TAI system with highly stable atomic clocks.
Ahmad Byagowi, a researcher at this company, assures CNET that the use of TAI avoids the problem for many years: “we anticipate that if we stick to TAI without observing leap seconds, we should be fine for at least 2,000 years.”
While some propose not to touch anything, others went ahead years ago and devised a mechanism to make the transition even more subtle, using milliseconds. In 2011, Google was already clearly talking about the headaches caused by the leap second, at which time it invented the “leap smear” technique.
[“Nos mataríamos antes de involucionar”: las teorías sobre el apocalipsis de una caída total de Internet]
Instead of adding a whole second to the clock all at once, so you don’t have to audit every line of code that depends on the time, (“That’s a lot of code!” they complained) decided to gradually add a couple of milliseconds to each update, applying the change smoothly before the end of the day was set.
That December 31, with the drop of sweat rolling down their foreheads, Google engineers were relieved as the servers continued as normal as they entered the new year. “We plan to use this technique again in the future, when new leap seconds are announced by IERS,” they concluded.
The Earth as seen from the International Space Station.
Another alternative that is gaining strength is the one proposed by the International Telecommunications Union. Consists in add an hour to atomic clocks every 600 years to avoid desynchronization. But while some prefer to advance the clock, others want to put it back an hour as well, but only when the variation has accumulated a delay of half an hour. Bon University calculated that with this system an adjustment would not be necessary until the year 2600.
A little less than 5 months from 2023, the technological community has to convince a good part of the actors that regulate time. The United Kingdom was in favor of keeping it the last time they met in Geneva, but the US NIST (National Institute of Standards and Technology) and the French BIPM (Bureau International de Poids et Mesures) are in favor of saying goodbye to leap second . It may be one less problem, but it sure isn’t the end of server crashes.