[CentOS] leap second and Centos

Chris Adams linux at cmadams.net
Fri Mar 6 21:15:55 UTC 2015


Once upon a time, Les Mikesell <lesmikesell at gmail.com> said:
> On Fri, Mar 6, 2015 at 2:45 PM, Chris Adams <linux at cmadams.net> wrote:
> > So again, if you want to make sure there's no new issue, you'll have to
> > set up a test yourself.  I doubt the 2008 or 2012 issues will happen
> > again, but there's plenty of room for new issues.
> 
> So are you saying that you think no one upstream has done any testing
> yet?  Or that I should have better resources for testing than they do?
>    I was hoping things weren't really that bad and that I just hadn't
> found the simple summary of results yet.

Like I said, probably someone that had an issue in 2012 has tested for
the 2012 issue, so that probably won't re-occur.  But that doesn't mean
that someone has tested every piece of software in every combination in
use.

Again, using the 2012 leap second as an example, I (and I expect others)
had experienced an issue in 2008, so I ran tests for that issue.  I
didn't even think about thread scheduling being a problem (and my
servers weren't hit by that anyway), so I didn't test for that, nor did
I do a "full up" test like I described initially.

So, it is possible that everything will be fine (there's been more
attention to leap second cases after the 2012 issue had wider impact
than the 2008 issue).  It is also possible that some _new_ type of issue
has been introduced in the last 2.5 years that won't appear until this
leap second, but if nobody tests for it, we won't know until the clock
ticks 2015-06-30 23:59:60.

Short answer: last time it was threaded stuff like Java, the time before
it was systems under heavy kernel loads.  Who knows, this time Postfix
could hang, or MySQL could corrupt databases, or something else.
Probably nothing will happen, but if you want a "cover your ass" report,
I don't think anybody has done that.

-- 
Chris Adams <linux at cmadams.net>



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