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This question suggests that the servers used in the SO rack are not properly time sync'd:

Was a question asked in the future?

  • How are the servers clocks set? (ie, NTP, or otherwise?)
  • Are they synchronized to the same source, each other, or what configuration do you use?
  • Do you have a single source you use, and what stratum level is it?
  • Who assigns a timestamp to a given post - the Database, or HTTP server?

I'm not so concerned about keeping time exact with the rest of the world, this is primarily due to the possibility of gaming the system.

I can imagine a scenario where the web-facing servers are tested to find out which one is 'slowest' - several seconds behind the other servers - and then using that very slight advantage to exploit the FGITW issue.

This would only work if

  • The servers are not adequately time synchronized (ie, to within a second)
  • The HTTP servers assign the official post time to the post

Granted, it's a small advantage, and possibly not worth worrying about, but you may find that over time other interesting problems crop up if the systems are not properly time synchronized. A good configuration using NTP should yield a server to server difference of less than 10mS - certainly enough to eliminate concerns over gaming, and to avoid other problems.

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So .. when do the friday posts start? –  Tyler Carter Jan 22 '10 at 15:38
    
Please, please, please don't tell me you're using the built-in windows time service... blogs.technet.com/askds/archive/2007/10/23/… –  Adam Davis Jan 22 '10 at 15:39
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@Chacha102 - Next Friday's posts start yesterday... meta.stackexchange.com/questions/36557/… –  Adam Davis Jan 22 '10 at 15:40

1 Answer 1

up vote 3 down vote accepted
+550

The database servers didn't have access to the internet any more, so their NTP calls to pool.ntp.org were failing. We set up an internal NTP source for them.

edit: this time, the Windows Time service was mysteriously stopped on 5 of 6 web tier servers, even though it's set to "Autostart". I restarted it. Event log shows nothing relevant. Who knew NTP was so freakin' complicated?

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But you're still using the windows time service? Does the database or the webserver "record" the time when the post is submitted? –  Adam Davis Jan 22 '10 at 19:59

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