REMINDER: LEAP SECOND

Majdi S. Abbas msa at latt.net
Wed Jun 24 16:05:00 UTC 2015


On Wed, Jun 24, 2015 at 08:33:14AM +0200, Tore Anderson wrote:
> Leap years and DST ladjustments have never caused us any major
> issues. It seems these code paths are well tested and work fine.

	I've seen quite a few people that for whatever reason insist
on running systems in local time zones struggle with the DST reverse
step.  It's not nearly as much of a non-issue as you claim.

> The leap second in 2012 however ... total and utter carnage.
> Application servers, databases, etc. falling over like dominoes. All
> hands on deck in the middle of the night to clean up. It took days
> before we stopped finding broken stuff.

	"Total and utter carnage" is a bit of a stretch.  Linux hosts
that ran applications dependant on nanosleeps needed reboots.  Note 
that this wasn't an issue in 2009, because the poorly tested change in
question hadn't yet been made to the Linux kernel.

	(Even in 2012, my personal hosts, running a different operating
system sailed through it just fine.)

	At any time, you might have a bad operational day for any number
of reasons.  Sure, that one was annoying, but to my knowledge nobody
died, and a lot of hosts that probably needed one anyway got a reboot.
Certainly, lately, I've seen a lot of Linux hosts rebooted more than
once for security patching.  #opslife?

	Cheers,

	--msa



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