The Leap Second That Froze the Web
In June twenty twelve, a single extra second added to global clocks exposed a latent defect in the Linux kernel, triggering a cascade of server failures that took down major websites and airline booking systems. This is the story of how a rare astronomical adjustment revealed the fragile assumptions buried in the code that runs the modern world.
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Atomic clocks drift from solar days because planetary wobbles make Earth's rotation inconsistent.
A Linux kernel bug caused CPUs to reach one hundred percent utilization processing millions of overdue alarms.
Reddit suffered a ninety minute outage because servers entered a livelock state during the leap second.
Australian Ethernet switches seized during the time shift, causing localized internet blackouts for two hours.
The POSIX standard ignores leap seconds by assuming every day contains exactly eighty-six thousand four hundred seconds.
Time smearing prevents system crashes by stretching the extra second over several hours instead of one moment.
- 01Intro1 min
- 02The Sixty-One Second Minute2 min
- 03The Livelock in the Kernel2 min
- 04The Infrastructure Cascade2 min
- 05The POSIX Problem and the Future of Time2 min
- 06Outro1 min
- Leap second bug cripples Linux servers at airlines, Reddit ...
- Leap second hits Qantas air bookings, while Reddit and ...
- 'Leap second' wreaks Internet havoc
- The 2012 Leap-Second Outage - CenterConsulting
- September 2012
- IERS Annual Report 2012
- June 30 ‘Leap Second’ Bug Briefly Knocks Out Reddit, Foursquare
- Impact of a Positive Leap Second Introduced In June
- Leap second bedevils Web systems over weekend
- "Leap Second" Becomes Giant Problem for Numerous Websites
- Time
- Fix leap seconds and add tai clock - LWN.net
- Five different ways to handle leap seconds with NTP
- 1.2.16 • leap-second-reference • testland • Registry • Tessl
- chrony.conf(5) - chronyd configuration file
- [PATCH 2/3] time: Fix leapsecond triggered hrtimer/futex load spike issue
- NTP and Clock Discipline - Linux Kernel Internals
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