[patrickmay]

A great example of Hyrum's Law:

"With a sufficient number of users of an API, it does not matter what you promise in the contract: all observable behaviors of your system will be depended on by somebody."

combined with failure to follow Postel's Law:

"Be conservative in what you send, be liberal in what you accept."

[mmastrac]

Postel's law is considered more and more harmful as the industry evolved.

[CodesInChaos]

That depends on how Postel's law is interpreted.

What's reasonable is: "Set reserved fields to 0 when writing and ignore them when reading." (I heard that was the original example). Or "Ignore unknown JSON keys" as a modern equivalent.

What's harmful is: Accept an ill defined superset of the valid syntax and interpret it in undocumented ways.

[n2d4]

Very much so. A better law would be conservative in both sending and accepting, as it turns out that if you are liberal in what you accept, senders will choose to disobey Postel's law and be liberal in what they send, too.

[esafak]

I think it is okay to accept liberally as long as you combine it with warnings for a while to give offenders a chance to fix it.

[ajross]

That's true, but sort of misses the spirit of Hyrum's law (which is that the world is filled with obscure edge cases).

In this case the broken resolver was the one in the GNU C Library, hardly an obscure situation!

The news here is sort of buried in the story. Basically Cloudflare just didn't test this. Literally every datacenter in the world was going to fail on this change, probably including their own.

[black3r]

> Literally every datacenter in the world was going to fail on this change

I would expect most datacenters to use their own local recursive caching DNS servers instead of relying on 1.1.1.1 to minimize latency.

[stevefan1999]

that means you did a leaky abstraction indirectly but it is on the people level

[chrisweekly]

Obligatory xkcd for Hyrum's Law: https://xkcd.com/1172