[ntp:questions] Re: Y2038 bug strikes early

David L. Mills mills at udel.edu
Tue Aug 1 19:40:23 UTC 2006


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 


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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