Comment by cek | Hacker News Reader

Comment by cek | Hacker News Reader

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I can confirm Paul helped drive MS's adoption of OSF DCE RPC.

Once he convinced me of the uniqueness of correctly generated UUIDs I coined the phrase "the likelihood of a UUID collision is the same as an avocado spontaneously turning into a grapefruit."

A fun tid-bit: At one point I was the maintainer of the list of static UUIDs with the Microsoft bit set. It was a flat text file checked into the windows source. I reserved a chunk of them for my own projects because having all those zeros was useful in debugging. E.g. "00000000-0000-0000-c000-000000000046" (the c000 indicates MS reserved).

In '97 I wrote the internet-draft [1] that Paul & Rich Salz finally turned into RFC 4122 in 2005 [2].

[1] https://www.ietf.org/archive/id/draft-kindel-uuid-uri-00.txt [2] https://datatracker.ietf.org/doc/rfc4122/

I am not sure how other people feel but despite me using the Internet for a good 24 years now I am still astonished at the connection possibilities it gives to us little people. Here I am, a man of little acclaim and communicate with people who wrote e2fsprogs and the uuid RFC and whatnot. This is still a wonder and I doubt it'll ever become an everyday feeling.

If a UUIDv4 is used, then yes, I'm convinced it will be random to within the amount of entropy the system provides.

If another UUID version is used, I'm extremely wary. MAC addresses are explicitly not unique. Worse, there are plenty of bargain mfgs that make cards all with the same MAC. There's a story of a local college that ordered several hundred cards for workstations and discovered every single one had the exact same hardware MAC. Large orgs will spot this easily, but there could be hundreds or thousands of individuals that never tried connecting the same bad cards on the same network segment.

In practice, you can usually depend on it to be truly unique. But there are several failure modes that you absolutely need to be aware of if you plan on using this in production.

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