madsim-rs/madsim

Health v2 · maintenance only

Flags: no_releases

Adoption not part of the score

1150 stars · 71 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

MadSim is a Rust async runtime similar to tokio that enables deterministic simulation testing for distributed systems. It mocks I/O interfaces, eliminates uncertainty, and injects chaos and failures so bugs can be reproduced deterministically.

Use cases

• deterministically test distributed systems in Rust
• reproduce race conditions and hidden bugs reliably
• inject network and node failures into async Rust code
• simulate tokio, tonic, etcd, kafka, and S3 clients in tests
• chaos-test a database or streaming system before deployment

When to choose

• you build distributed systems in Rust and want FoundationDB-style deterministic simulation testing
• you need reproducible failure injection and chaos testing for async Rust code
• you want to swap tokio/tonic/etcd-client/rdkafka with drop-in simulated versions

When to avoid

• your code depends on crates without madsim-compatible replacements or patches
• you only need conventional integration or end-to-end testing without determinism
• you are not writing Rust async applications

Facets

library · maturity active

testing simulation mocking concurrency microservices testing developer-tools rust cross-platform deterministic-simulation chaos-testing async-runtime tokio-alternative fault-injection

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