3 ms·

Author here - happy to answer any questions you may have. I originally submitted the post in 2021, but it was (somehow) picked up for a second chance. The wor

Author here - happy to answer any questions you may have. I originally submitted the post in 2021, but it was (somehow) picked up for a second chance. The work has evolved into a Rust project Temper[1], which features a fairly intricate simulation of the Rust/C++11-without-consume memory model, supporting a superset of what Loom's atomics can simulate, but it's much much slower. It also contains the most comprehensive set of C++11 memory model tests that I'm aware of, with test cases sourced from books, blog posts, Stack Overflow and the C++ standard. I'd love to be pointed at something larger, if it exists. [2] [1] https://github.com/reitzensteinm/temper https://github.com/reitzensteinm/temper [2] https://github.com/reitzensteinm/temper/tree/main/memlog/tests https://github.com/reitzensteinm/temper/tree/main/memlog/tes...

elliotpotts 2y ago
I'd like to see a post on fuzzing distributed applications rather than memory models. I understand the underlying principle is the same, but having only seen memory models be tested I can't quite shift my perspective enough to figure out how fuzzing processing communicating over networks would work. The SQL transaction post would be a nice perspective too. Is this still in the works?
- reitzensteinm 2y ago
  Progress is slow, but I've been maintaining the Rust version when I have time. The MVP of fuzzing network communications and disk access is fairly easy, but there is a long tail of very complicated behaviour I'd like to simulate. Dan Luu's site [1] goes into a fair bit of detail on the disk side. I see no reason why you can't emulate a superset of the worst case behaviour, and have a great deal of confidence that you're using file access in a way that won't result in corruption. Networks will have a similar long tail, e.g. asymmetric net splits. The SQL version is a bit trickier, as the API is much wider. The abstraction I was working on was essentially that you get select, insert and update, and write anything more complicated yourself. This works for replicating the skews and other phenomena described in DDIA [2], but it runs into the same core problem that you're simulating a model of your code, not your code itself. The best pathway for temporal fuzzing databases with production loads is probably at the network layer. [1] https://danluu.com/file-consistency/ https://danluu.com/file-consistency/ [2] https://www.amazon.com.au/Designing-Data-Intensive-Applications-Reliable-Maintainable/dp/1449373321 https://www.amazon.com.au/Designing-Data-Intensive-Applicati...
  - elliotpotts 2y ago
    Great, thank you for the reading!

elliotpotts 2y ago

I'd like to see a post on fuzzing distributed applications rather than memory models. I understand the underlying principle is the same, but having only seen memory models be tested I can't quite shift my perspective enough to figure out how fuzzing processing communicating over networks would work. The SQL transaction post would be a nice perspective too. Is this still in the works?

reitzensteinm 2y ago
Progress is slow, but I've been maintaining the Rust version when I have time. The MVP of fuzzing network communications and disk access is fairly easy, but there is a long tail of very complicated behaviour I'd like to simulate. Dan Luu's site [1] goes into a fair bit of detail on the disk side. I see no reason why you can't emulate a superset of the worst case behaviour, and have a great deal of confidence that you're using file access in a way that won't result in corruption. Networks will have a similar long tail, e.g. asymmetric net splits. The SQL version is a bit trickier, as the API is much wider. The abstraction I was working on was essentially that you get select, insert and update, and write anything more complicated yourself. This works for replicating the skews and other phenomena described in DDIA [2], but it runs into the same core problem that you're simulating a model of your code, not your code itself. The best pathway for temporal fuzzing databases with production loads is probably at the network layer. [1] https://danluu.com/file-consistency/ https://danluu.com/file-consistency/ [2] https://www.amazon.com.au/Designing-Data-Intensive-Applications-Reliable-Maintainable/dp/1449373321 https://www.amazon.com.au/Designing-Data-Intensive-Applicati...
- elliotpotts 2y ago
  Great, thank you for the reading!