Whenever we see a major internet outage like this past week's multi-billion dollar Amazon Web Services debacle, I like to come into work and crack wise: "Bumped into a server rack with my big ass and unplugged it this morning, hope nobody notices!" I may have been closer to the mark this time: As reported by Ars Technica, Monday's outage was shockingly caused by a single software glitch whose effects cascaded through AWS' systems, though no one's tuchus appears involved.
The culprit was a software bug in DynamoDB, AWS' DNS management system. DNS or "Domain Name System" is often analogized as the phone book of the internet, translating domain names preferred by human users into the IP addresses required by automated systems. On the modern internet, many services, such as cloud computing or streaming, need to be able to assign the same domain to multiple IP addresses in a network, allowing efficient use of geographically distributed servers.
