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Comment by 8cvor6j844qw_d6 | Hacker News Reader

I'll be interested in the incident writeup since DNS is mentioned. It will be interesting in a way if it is similar to what happened at AWS.

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It's pretty unlikely. AWS published a public 'RCA' https://aws.amazon.com/message/101925/. A race condition in a DNS 'record allocator' causing all DNS records for DDB to be wiped out.

I'm simplifying a bit, but I don't think it's likely that Azure has a similar race condition wiping out DNS records on _one_ system than then propagates to all others. The similarity might just end at "it was DNS".

https://isitdns.com/

That RCA was fun. A distributed system with members that don't know about each other, don't bother with leader elections, and basically all stomp all over each other updating the records. It "worked fine" until one of the members had slightly increased latency and everything cascade-failed down from there. I'm sure there was missing (internal) context but it did not sound like a well-architected system at all.

Needs STONITH

>slightly increased latency

They didn't provide any details on latency. It could have been delayed an hour or a day and no one noticed

It's always DNS

It is a coin flip, heads DNS, tails BGP

THIS is the real deal. Some say it's always DNS but many times it's some routing fuckup with BGP. two most cursed 3 letter acronym technologies out there

when a service goes down it's DNS when an entire nation or group of nations vanish it's BGP.

DNS has both naming and cache invalidation, so no surprise it’s among the hardest things to get right. ;)

That's three of the hardest problems in CS ))

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