CYcyanf·Jan 7, 2026Submission
Madsim: Deterministic Simulator for Distributed Systems in Rust
1 points · Open discussionmadsim-rs
madsim
Rust2023–2026
madsim-rs / madsim
madsim
Magical Deterministic Simulator for distributed systems in Rust.
4Distinct people
4Mentions
0Explicit recommenders
1.2KGitHub stars
What to know before exploring
What it is
Magical Deterministic Simulator for distributed systems in Rust.
GitHub
Where it is used
No documented product use has been verified yet.
What people are saying
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This week on Hacker News
Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 5:04:57 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by year4 dated mentions
Observed mentions: 2023-04-16 22:15:57 UTC to 2026-01-07 13:18:51 UTC.
* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 1 | 1 | 0 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 2 | 1 | 1 |
| 2025 | 2025-01-01 00:00:00 UTC | 2026-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2026 (partial) | 2026-01-01 00:00:00 UTC | 2027-01-01 00:00:00 UTC | 1 | 1 | 0 |
What Hacker News says
4 sourcesMadSim: Deterministic Simulator for Distributed Systems
1 points · Open discussionI've been super interested in this field since finding out about it from the `sled` simulation guide [0] (which outlines how FoundationDB does what they do).
Currently bringing a similar kind of testing in to our workplace by writing our services to run on top of `madsim` [1]. This lets us continue writing async/await-style services in tokio but then (in tests) replace them with a deterministic executor that patches all sources of non-determinism (including dependencies that call out to the OS). It's pretty seamless.
The author of this article isn't joking when they say that the startup cost of this effort is monumental. Dealing with every possible source of non-determinism, re-writing services to be testable/sans-IO [2], etc. takes a lot of engineering effort.
Once the system is in place though, it's hard to describe just how confident y
Read the rest
ou feel in your code. Combined with tools like quickcheck [3], you can test hundreds of thousands of subtle failure cases in I/O, event ordering, timeouts, dropped packets, filesystem failures, etc.
This kind of testing is an incredibly powerful tool to have in your toolbelt, if you have the patience and fortitude to invest in it.
As for Antithesis itself, it looks very very cool. Bringing the deterministic testing down the stack to below the OS is awesome. Should make it possible to test entire systems without wiring up a harness manually every time. Can’t wait to try it out!
[0]: https://sled.rs/simulation.html
[1]: https://github.com/madsim-rs/madsim?tab=readme-ov-file#madsi...
[2]: https://sans-io.readthedocs.io/
[3]: https://github.com/BurntSushi/quickcheck?tab=readme-ov-file#...
Madsim: Magical Deterministic Simulator for distributed systems in Rust
2 points · Open discussion