[ntp:questions] Re: Y2038 bug strikes early
David L. Mills
mills at udel.edu
Tue Aug 1 19:40:23 UTC 2006
Marc,
Unix doesn't have to have a 2038 rollover problem, just as NTP doesn't
have a 2036 rollover problem. Evidence to this assertion has been
reported in recent messages to this list and the hackers at ntp.org support
group. It's all in the carefully designed 64-bit twos complement
calculations that determine the relative date and time, as long as the
clock is set first within 68 years of the actual calendar date. See
http://www.eecis.udel.edu/~mills/y2k.html.
Dave
Marc Brett wrote:
> From the latest RISKS Digest:
>
>
> Date: Thu, 29 Jun 2006 13:38:25 -0700
> From: Conrad Heiney <conrad at fringehead.org>
> Subject: Y2038 bug strikes early
>
> Starting on May 12, 2006, many installations of the AOLServer web server
> failed. Not all versions or all configurations failed, but the ones that did
> became unusable. On start, the server would eat virtual memory and then
> terminate with a memory allocation error. Discussion on the mailing list
> revealed the starting date of the problem, indicating that some part of the
> software had a clock issue. On careful inspection it was discovered that
> database threads were a common factor. It was then noted by a perceptive
> person that the servers all failed on or before exactly one billion seconds
> before the end of the Unix epoch in 2038. Many installations had very long
> database timeouts, which caused the software to look ahead and see the End
> of Time. Adjusting the timeouts stopped the crashes.
>
> The risk of the known clock bug striking 32 years early indicates there may
> be other "pre-problems" lurking in software that will show up long before
> the date we have comfortably set as the deadline.
>
> The thread discussing the problem and its resolution is here:
> http://www.mail-archive.com/aolserver@listserv.aol.com/msg09812.html
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