Comment by lucb1e | Hacker News Reader

Comment by lucb1e | Hacker News Reader

This sounds rather exaggerated to me. 10% of the systems will have trouble with it? Perhaps during the leap second something will bug or look weird, but outside of that second I doubt it's even 1% that will have trouble recovering. Also, many systems don't even support the leap second, nothing will happen at all until they sync with time servers the next time and correct for the second. Many systems are off a second or so anyway.

As a quick example, Javascript is not designed to handle leap seconds correctly, so I doubt we'll ever see the value 60 out of new Date().getSeconds(). Things will just be off by 1 second for a second.

Edit: Another example from the Windows Time service:

> The Windows Time service does not indicate the value of the Leap Indicator when the Windows Time service receives a packet that includes a leap second. [...] Therefore, after the leap second occurs, the NTP client that is running Windows Time service is one second faster than the actual time. This time difference is resolved at the next time synchronization.

It will just be a second off and resynchronize next time.

If your system is one of those 10% and if your trading algo is executing fucked up trades because of timing issues and you lose real money - I wouldn't call that exaggerated.

Also, not sure if any of the systems mentioned in the article run JS for critical server side code.

High-frequency trading and other important realtime processes that handle money should of course be tested for this scenario (either by simply not trading for a few seconds before and after, or by properly handling it). The vast majority of the computer systems around the world are however not HFT systems and the world will continue to work normally. No Y2K-like doom scenarios needed like the article suggests.

We've been here before, June 30th 2012 also contained a leap second (see Wikipedia). The article only forecasts doom without looking back at previous leap seconds and evaluating its effect.

> We've been here before, June 30th 2012 also contained a leap second (see Wikipedia). The article only forecasts doom without looking back at previous leap seconds and evaluating its effect.

Clearly you didn't read the article.

If you had you would have seen that they noted that last time it was on a weekend when all the markets were closed.

I did know that. I just don't consider HFT to be so important compared to, say, traffic lights and apache servers continuing to function.

> I did know that. I just don't consider

That isn't what you said in your post, now is it? You said "We've been here before", but as the article points out, we have not.

In any case,

Traffic lights and apache for the most part do not care what time it is - and certainly not to the second. Market orders are timed to the millisecond, they care very much.

Slewing vs stepping or any other de-synchronization could cause chaos with them, not so with most other fields. You might not care about HFT, but this applies to all orders, not just HFT. And like it or not the stock market plays a large role in everyday life.

Unless you are someone who keeps all your money in physical cash and drives cars for a living, there is no way HFT is less important than traffic lights; one keeps the economy of the world flowing, the other stops people getting driving tickets.

"Being a second off and resynchronizing next time" could be a million dollar difference, there is no way that you can shrug that off.

As a developer for a financial firm, this leap second is an extremely big deal; the fact that this is the first time in history that financial markets (which are normally millisecond accurate) have had to deal with this phenomenon will absolutely result in something somewhere going wrong.

This article isn't exaggerated; it's there to highlight what's going on for the traders and brokers who aren't technologically advanced.

> ah yes, the usual "HFT is the best invetion since wheel and fire" mantra...

again, same question - who cares? apart from some already super rich HTF guys.

> "something somewhere going wrong" - um, this is practically constant situation for quite some time, in or out of markets. But don't let my relaxed monday mood disturb your doomsday freaking out :)

> This article isn't exaggerated; it's there to highlight what's going on for the traders and brokers who aren't technologically advanced.

traders and brokers who do actual trading and not HFT will not be affected directly by that (ie their books), it's more like a sidenote that "if you see some blip in feeds during that time, this might explain it"

  there is no way HFT is less important than traffic lights
  one keeps the economy of the world flowing, the other 
  stops people getting driving tickets.

The New York Stock Exchange is closed for 17.5 hours each day, and the entire weekend. I doubt the world economy is going to stop flowing if they're closed for an extra second - or even if a few people take their systems offline for several minutes to restart them.

Stocks are a very, very small part of the financial markets. Forex and futures markets are open most of the week and a lot more money flows through them. Forex alone accounts for about five trillion USD per DAY of money movement. Stocks are barely a blip on the radar in comparison.

And yet all of the major exchanges have mandated down times that even small e-retail operators would kill for.

This thread has reached sort of silly proportions. Of course electronic trading impacts most people's lives even if they don't want it to, but in reality the markets are largely self correcting at this level, so even if there is some oddity associated with the leap second it likely won't have long term (or maybe even observable) impact on the wider world.

Agreed on all points!

That leap second pinned loads of Linux boxes at 100% CPU. I'm a customer of Hetzner, they sent out a mail asking the customers to check their machines as their power draw increased by a megawatt in an instant.

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