Outage case study9 min
Staying up and correct when parts of the system fail.Metrics, logs and traces that show what a system is doing.Authentication, authorization and protecting data from abuse.
PremiumFacebook: the day the DNS servers hid
October 2021. One command cut every Facebook data centre off, and its DNS servers, as designed, withdrew themselves from the internet.
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What’s inside
- At a glance
- What users saw
- Timeline
- The root cause
- Why it spread
- How it was fixed
- Design lessons
- The interview angle
- Sources