Let me share a war story with you (one that I swear is true).
In the year 2000 an Ansett passenger jet, loaded with passengers, was preparing to push back from the terminal in Sydney. But there was a timing problem… the control tower insisted they were trying to depart too early… three minutes too early.
What resulted was a dispute about the actual time, which concluded with the control tower politely suggesting Ansett ring 1194 (the phone number in Australia to get the talking clock). One phone call later and Ansett could see the problem: Their mainframe was 3 minutes fast. Seriously!
The root cause of this problem was simple: while Ansett used sysplex timers (Mainframe timing devices) to co-ordinate time between their mainframes, nothing had been setup to co-ordinate the sysplex timer time with an external source. And sadly the time had drifted.
The solution was simple. We attached a modem to the sysplex timer and it began calling the NIST in Boulder Colorado to check for drift (this product had no concept of NTP). Meanwhile the Sysplex Timer had to very slowly (and it took a while) drift it’s reported time back to reality.
So Ansett had broken the first law of the Time Lords: Always sync your clocks. Pretty well every product in your data center can sync with NTP and there is no excuse not to use it.
So given my very strong views on this, I am curious, have I missed something? Are there reasons to NOT use NTP? Have you seen objections? Please share your thoughts.
And Ansett? Sadly no longer with us. The airline failed in September 2001, their planes sold off or broken down for scrap. A sad day for Australian aviation and all the people who worked for that fine airline.