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Leap second causing Linux server crashes?

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Re: Leap second causing Linux server crashes?

#111

Post by moe »

rplnt wrote: post #109
moe wrote: post #97

Earlier quoted context omitted.

Where was it published? Almost all of my machines run the Debian stable kernel and were still affected.

The leap second was scheduled in January. That event is so unusual you might get worried. So you do a simple google search and find out that there was a critical bug[1] in Linux kernel last time leap second was inserted. People got worried rightfully[2][3]. I don't know about debian, if it was known prior, if it is the same bug as before, ... But I don't run Debian, you do. 1. https://bugzilla.redhat.com/show_bug.cgi…

No need to be a smart-ass about it.

Even if I had googled (which I didn't) then I'd probably have assumed the fixes for bugs from 2009 to have long made it into the current distro kernels.

I just didn't expect something so basic to be still (or again) broken.

Re: Leap second causing Linux server crashes?

#112

Post by ChuckMcM »

jerf wrote: post #53
noselasd wrote: post #38

Earlier quoted context omitted.

Why does everyone always say Y2K wasn't an issue ? I'm sure there were a lot of consultant making too much money with little work - however _alot_ of bug fixes were done, that would have caused problems. So because it was taken seriously , stuff were fixed and issues didn't happen because of that. Personally, I fixed 3 Y2K bugs back then, 2 of them would have brought down a rather critical business support to simply…

"Why does everyone always say Y2K wasn't an issue?" From the outsider's perspective, it is indistinguishable from any number of other putative disasters that required lots of money to fix, yet didn't come to pass... in some cases including putative disasters in which the money wasn't spent and the disaster didn't happen anyway. I have the insider's perspective and I agree that it is the more accurate, that Y2K was, i…

This.

Many, if not a majority, of my non-technical friends and acquaintances have expressed at one time or another a reference to the "Y2K disaster" and rolled their eyes to suggest it was somehow not an issue. I was the 'Y2K compliance officer' at my startup at the time (we even got certified, and that actually may have been a scam (the certifying part)) but we identified and fixed a number of issues our box would have suffered had we not done the work.

Re: Leap second causing Linux server crashes?

#113

Post by ajays »

wiredfool wrote: post #107
kristopher wrote: post #96

FYI: Our Debian servers did not kernel panic but system CPU load went through the roof; A quick restart brought levels back to normal.

My Ubuntu 10.04 desktop went to 100% proc and load avg of 20, none of my 10.04 servers or Debian stable servers were affected. This fixed it: date; sudo date `date +"%m%d%H%M%C%y.%S"`; date;

You are a lifesaver. All morning my desktop's load has been pegged at 20. I upgraded FF, Chrome, etc. and no impact. I was dreading a full re-start, as I have lots of windows, tabs, etc. open. The above command knocked the load down to almost nothing in seconds.

Re: Leap second causing Linux server crashes?

#114

Post by [deleted] »

mjschultz wrote: post #17
mkr-hn wrote: post #13

Is this implementation-specific, or could the Windows equivalent to ntp cause the same problem?

Implementation specific. It looks like it is a bug in the Linux kernel with how it adjusts the time. It is possible that Windows, OS X, and other BSDs will be affected by a similar bug, but that would be coincidental as the bug is not due to ntpd but rather how the kernel handles a request that ntpd generates. More specifically, there is a condition in which the kernel tries to insert a leap second and, in doing so,…

[deleted]

Re: Leap second causing Linux server crashes?

#115

Post by pbhjpbhj »

andreasvc wrote: post #102
chimeracoder wrote: post #63

Earlier quoted context omitted.

What is time, other than a state in which net entropy within a closed system increases (which is already a definition abstract enough that it almost misses the point)?

That's not really a definition of time, just a way to postulate its direction. Time as a physical unit has been decreed to be the rate of decay of a certain Cesium atom; i.e., a fixed regular interval, whereas the increase of entropy varies from moment to moment. E.g. right now I'm typing and before I wasn't, that doesn't mean time is going ever so slightly faster because of that ...

>rate [sic] of decay of a certain Cesium atom //

That is time in the same way that leaves moving on a tree is wind.

The instance of the radioactive decay indicates the defined period of time has passed within the local frame of reference. That tells us very little useful about time itself.

Re: Leap second causing Linux server crashes?

#116

Post by andreasvc »

pbhjpbhj wrote: post #115
andreasvc wrote: post #102

Earlier quoted context omitted.

That's not really a definition of time, just a way to postulate its direction. Time as a physical unit has been decreed to be the rate of decay of a certain Cesium atom; i.e., a fixed regular interval, whereas the increase of entropy varies from moment to moment. E.g. right now I'm typing and before I wasn't, that doesn't mean time is going ever so slightly faster because of that ...

> rate [sic] of decay of a certain Cesium atom // That is time in the same way that leaves moving on a tree is wind. The instance of the radioactive decay indicates the defined period of time has passed within the local frame of reference. That tells us very little useful about time itself.

I wasn't making a philosophical statement, I specifically qualified it by saying "as a physical unit." That's still nowhere near precise enough, but I only meant to point out that we typically don't conceive of time as an emergent property of physical processes (i.e., entropy change), but as a local property of a very specific atom, such that time passes at a constant rate, if only because we choose to define it that way. "Telling something about time itself" sounds like a philosophical question which I fear has no definite answer.

Re: Leap second causing Linux server crashes?

#117

Post by rplnt »

moe wrote: post #111
rplnt wrote: post #109

Earlier quoted context omitted.

The leap second was scheduled in January. That event is so unusual you might get worried. So you do a simple google search and find out that there was a critical bug[1] in Linux kernel last time leap second was inserted. People got worried rightfully[2][3]. I don't know about debian, if it was known prior, if it is the same bug as before, ... But I don't run Debian, you do. 1. https://bugzilla.redhat.com/show_bug.cgi…

No need to be a smart-ass about it. Even if I had googled (which I didn't) then I'd probably have assumed the fixes for bugs from 2009 to have long made it into the current distro kernels. I just didn't expect something so basic to be still (or again) broken.

Don't get me wrong, I wouldn't too by default. But do you remember Azure crashing on February 29th? And checking for that date is a matter of three conditions. Leap second is much more complex. I'm not trying to be a smart-ass.. I'm just saying it's something I would worry about and would try to find something about it. And perhaps it wouldn't lead anywhere with Debian.

And still, something in your app stack could crash on this as well, leaving the kernel patching pointless.

Re: Leap second causing Linux server crashes?

#119

Post by infinite8s »

joelhooks wrote: post #60
infinite8s wrote: post #52

Earlier quoted context omitted.

When people say mid-six figures, do they mean 500k? Or 150k?

$100/h approaches $200k, and consultants can definitely make $250/h+.

Yeah, but that rate usually assumes they aren't billing 40hr/weeks for 50 weeks a year.

Re: Leap second causing Linux server crashes?

#120

Post by joelhooks »

infinite8s wrote: post #119
joelhooks wrote: post #60

Earlier quoted context omitted.

$100/h approaches $200k, and consultants can definitely make $250/h+.

Yeah, but that rate usually assumes they aren't billing 40hr/weeks for 50 weeks a year.

Does it? I've had 50 week years as a consultant where it was 40-60hrs a week. Rough years. Profitable though. What would be nice is 25wks at the higher rates.
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