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This is true if you're working with documents edited by different devices, but many CRDTs do not and can indeed be not only "convergent" but also "correct". Ho
by ErikBjare 2y ago
This is true if you're working with documents edited by different devices, but many CRDTs do not and can indeed be not only "convergent" but also "correct".
How SSB works is a good example.
- vlovich123 2y agoCan’t find what SSB is. Can you clarify? But yes, it’s possible there are applications that can constrain the set of operations such that the merged result is also correct. I was just highlighting that CRDTs are trotted out as a catch all when a) it’s just a way of thinking about the problem rather than an actual algorithm (eg while there’s a lot of CRDT work for document editing, that work has to be done for scratch for any other problem domain) b) you have to modify your problem constrains and solution such that merge results are correct. B is a very very hard problem in a distributed system even if you ignore the challenge of a which itself is quite hard. I wouldn’t trust anything in this space too much without a TLA+ proof that it’s correct (unless it’s something low stakes like document editing).
- endgame 2y agoI think SSB is "Secure Scuttlebutt": http://ssbc.github.io/ssb-db/ http://ssbc.github.io/ssb-db/
- threatofrain 2y agoSome of our most important DB sync'ing algorithms were only very recently verified. It was okay to run the whole world's systems, including hospitals and armed forces this way. Very very few industry algos receive formal verification.