rinha2-back-end-rust

Rust/Actix-web 4 implementation for the Rinha de Backend 2024/Q1 challenge with SQLx async driver and PostgreSQL stored procedures

Live demo → | Documentation →

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About

A Rust implementation of the Brazilian backend challenge Rinha de Backend 2024/Q1, where a fictional bank API must handle concurrent transactions under strict resource constraints (1.5 CPU, 550MB RAM total). Built as a minimal single-file API (~140 lines) using Actix-web 4 with Tokio async runtime and SQLx 0.8 for compile-time checked PostgreSQL queries.

Tech Stack

Technology	Version	Purpose
Rust	1.94	API implementation
Actix-web	4	Async HTTP framework
SQLx	0.8	Compile-time checked PostgreSQL driver
Tokio	1	Async runtime
PostgreSQL	16.7	Database with stored procedures
NGINX	1.27	Reverse proxy and load balancer (least_conn)
Docker	-	Multi-stage build and orchestration
k6	-	Stress testing

Architecture

NGINX (:9999, least_conn)
├── webapi1-rust (:8080, 0.4 CPU, 100MB)
├── webapi2-rust (:8080, 0.4 CPU, 100MB)
└── PostgreSQL (0.5 CPU, 330MB)
    ├── InsertTransacao() — atomic balance update + validation
    └── GetSaldoClienteById() — statement with JSONB aggregation

Service	CPU	RAM
webapi1/2	0.4 each	100MB each
PostgreSQL	0.5	330MB
NGINX	0.2	20MB
Total	1.5	550MB

Features

• Minimal single-file API implementation (~140 lines of Rust)
• Zero-cost async with Tokio runtime and Actix-web
• SQLx compile-time query validation with offline cache (.sqlx/)
• PostgreSQL stored procedures for atomic server-side business logic
• UNLOGGED tables for maximum write throughput (no WAL)
• Lazy static HashMap for client validation (no DB round-trip)
• PostgreSQL tuned: synchronous_commit=0, fsync=0, full_page_writes=0
• Multi-platform Docker image (amd64/arm64) published to GHCR
• Observability stack with Prometheus, Grafana, and InfluxDB
• All requests under 800ms at 250MB RAM usage (60% below limit)

Getting Started

Prerequisites

• Docker with Docker Compose

Quick Start

git clone https://github.com/jonathanperis/rinha2-back-end-rust.git
cd rinha2-back-end-rust
docker compose up nginx -d --build

API available at http://localhost:9999

API Endpoints

Method	Path	Status Codes	Description
POST	/clientes/{id}/transacoes	200, 404, 422	Submit debit or credit transaction
GET	/clientes/{id}/extrato	200, 404	Get account balance statement
GET	/healthz	200	Health check

Run Stress Tests

docker compose up k6 --build --force-recreate

Project Structure

rinha2-back-end-rust/
├── src/WebApi/
│   ├── main.rs              # Complete API (~140 lines)
│   ├── Cargo.toml           # Dependencies
│   ├── Dockerfile           # Multi-stage: rust:1.94 → debian:bookworm-slim
│   └── .sqlx/               # SQLx offline query cache
├── docker-entrypoint-initdb.d/
│   └── rinha.dump.sql       # Schema + stored procedures + seed data
├── docker-compose.yml       # Dev stack with observability
├── prod/docker-compose.yml  # Prod stack with GHCR images
├── nginx.conf               # Load balancer config
└── .github/workflows/       # CI/CD (build-check, main-release, codeql)

CI/CD

Workflow	Trigger	Description
Build Check	Pull requests	Cargo build (release) + Docker health check
Main Release	Push to main	Build + Multi-platform Docker push (amd64/arm64) to GHCR + k6 load test + GitHub Pages report
CodeQL	Push/PR + weekly	Security and quality analysis for Rust
Deploy	Push to main	Deploy documentation to GitHub Pages

Docker image: ghcr.io/jonathanperis/rinha2-back-end-rust:latest

License

MIT — see LICENSE