Monthly Archives: July 2010

Not That Pretty to debug (NTP)

Today’s escapade in server administration reminded me of the absolutely most difficult and frustrating job in IT. That would be “Debugging time dependent or time sensitive applications.”

Here is a couple of real world cases to ponder upon:

1) Once I had a predictive dialer based call center stop functioning because of time differences. The asterisk server and the database server had a one minute (yes that is a single 1) time difference between them. After a full hectic hour of reading PERL code in a frenzy I found out that there was a magic stanza that read: if you have more than 30″ time difference in status updates, assume that the agents are off line. Cute uh ?

2) A newly minted SQUID server stopped serving cache hits because that new fangled version does time/date comparisons differently. So it validated the page’s expiration time the web server sent back and decided that it should NOT cache the query because it was expired. Half a workday lost! Cute uh?

So all you admins, don’t be cute, do NOT play loose with a system’s clock , more things than you can imagine might depend on date/time synchronization.

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