# tokio-rs/turmoil

Add hardship to your tests

Repository: https://github.com/tokio-rs/turmoil
Canonical: https://ross.abutalabs.com/products/turmoil
Language: Rust
License: MIT
License Family: permissive
Last push: 2026-07-21T16:26:09+00:00

## Health v2 (maintenance only)
Score: 86/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 93, release rhythm 69, longevity 100
- inputs: {"age_days": 1491, "days_push": 43, "days_rel": 131, "gap_med": 86, "n_releases_24m": 6}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1250, forks 74 (observed 2026-08-28T04:04:07.916054+00:00)

## What it is
Turmoil is a family of Rust crates for deterministic simulation testing of distributed systems, running multiple concurrent hosts on a single thread. It injects hardship such as latency, drops, partitions, crashes, and torn writes into simulated networks and filesystems under manual control or a seeded RNG.

## Use cases
- test distributed systems against network partitions deterministically
- simulate latency and packet drops in Rust integration tests
- reproduce race conditions with seeded RNG simulation testing
- test crash recovery and torn write handling
- simulate a tokio network stack in-process
- test filesystem failure handling with a simulated fs

## When to choose
- you build distributed systems in Rust and need deterministic fault injection
- you want reproducible tests for network partitions and crashes
- you use tokio and want drop-in simulated net/fs replacements

## When to avoid
- you need to test real network behavior against actual hosts
- your code is not written in Rust or not adaptable to simulated IO
- you only need simple unit or property testing without fault injection

## Facets
- artifact type: framework
- maturity: active
- function: testing, simulation, developer-tools
- domain: testing, microservices, developer-tools
- platform: rust, cross-platform
- tags: deterministic-simulation-testing, network-partition-testing, fault-injection, tokio

## Member repositories
- tokio-rs/turmoil (main) score 86

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:07.916054+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T05:07:45.840643+00:00, confidence not recorded.
  - readme: https://github.com/tokio-rs/turmoil (fetched 2026-08-28T04:04:07.916054+00:00, sha 6ddf26224596)
  - registry_crates: https://crates.io/api/v1/crates/turmoil (fetched 2026-08-29T12:18:36.755842+00:00, sha 98abff9d1825)
- Data as of 2026-08-30T08:39:29.467469+00:00.