#incident-response

On 2 July 2019 a single new firewall rule took Cloudflare, and a large part of the web with it, offline for 27 minutes. Not an attack, not a hardware failure. How does one rule do that to every server at once?

Something's on fire in production and you're the one holding it. Your job for the next fifteen minutes is to shrink the impact and coordinate the response, not to find the root cause.