Docs: Add caveat about madsim reproducibility
kwannoel opened this issue · comments
Initially observed here: risingwavelabs/risingwave#7901
Across various build environments the behaviour of RNG in a system may change, if they use from_entropy for instance.
Or even just compilation might produce different ordering of rng writes and reads.
It should behave the same only with the same build.
For example: we can run the original binary, it should yield the same result with the same SEED.
Alternatively: Ensure build environment is the same (compiler, os, commit).
Should add some caveat about this in docs + output on how to reproduce when madsim cluster crashes.
may /assign me 😆
Sure, it would be great to have such documents for developers. Please feel free to add them. Thanks in advance!
More specific details:
- OS must be same.
- Commit must be same.
- Compiler toolchain must be same.
We can list these as some examples. I'm not sure if it's enough, maybe we can write some tests to verify 🤔