We knew we wanted to build out the election results as part of our usual stack, but we also knew the setup — given its scale and profile — needed to be resilient against the following:
Varnish failure — varnishd, so far, has never crashed on us. But hardware failure, misconfiguration or a strange bug could also put varnish offline.Application errors — no matter how rigorous your testing, live data feeds for live events always invite unexpected quirks. We wanted our readers to be well-insulated from any errors that might crop up.Extreme traffic — historically, election nights bring some of the most intense traffic of the year. Not only did we want to avoid overloads, but we also wanted to make sure response times were consistent and fast.
(Link: Using Flat Files So Elections Don’t Break Your Server – NYTimes.com)