Machine Gun

A performance-focused load testing tool and event simulator for RabbitMQ and Kafka. It lets you define message schemas, generate realistic payloads at high velocity, and orchestrate complex testing flows.

What it does

• Define and store nested message schemas.
• High-velocity generation (100k+ msg/s) using worker threads.
• Supports RabbitMQ and Kafka with drift-corrected rate limiting.
• Automatic infrastructure setup for RabbitMQ (queues/exchanges).
• Graph-based orchestration for complex simulation flows.
• Real-time activity monitoring and RPC response tracking via the Live Hub.

Architecture

Monorepo structure

• apps/backend — NestJS + Fastify API/WebSocket server with multi-threaded generation and flow orchestration.
• apps/frontend — Angular 21 dashboard with signal-based state and premium orchestration controls.
• apps/test-consumer — High-coverage test app for RabbitMQ (RPC, TTL, Priority, Auto-delete) and Kafka verification.
• packages/common — Shared TypeScript contracts and utilities (@machine-gun/common).

Prerequisites

• Node.js 22+
• pnpm 10+
• RabbitMQ reachable from backend (RABBIT)
• Kafka optional (KAFKA)

Quick start

pnpm install
pnpm dev

pnpm dev now starts the backend, frontend, and the test-consumer app through Turborepo.

Useful scoped commands:

• Frontend only: pnpm dev:ui
• Backend only: pnpm dev:api
• Test consumer only: pnpm dev:test-consumer
• Full build: pnpm build
• Full test suite: pnpm test

Docker compose

The root compose file runs the full local stack:

docker compose up --build

Services exposed on the host:

🐳 Docker (Quick Start)

The easiest way to run Machine Gun is using the unified Docker image which contains both the UI and the API.

docker compose up --build -d

Access the UI at http://localhost:3000.

🛠 Local Development

1. Start backend and frontend.
2. Open the UI at http://localhost:4200.
3. Create or import schemas.
4. Run burst/continuous tests or start a flow from the canvas.
5. Monitor transport health, throughput, node states, and RPC responses in real time.

Testing

• Backend tests: pnpm --filter backend test
• Frontend tests: pnpm --filter frontend test
• Workspace tests: pnpm test
• Coverage (All apps): pnpm test:coverage (Automatically opens HTML reports in your browser)

Tech stack

• Backend: NestJS 11, Fastify, Socket.IO, RabbitMQ, KafkaJS, Piscina.
• Frontend: Angular 21, Signals, Tailwind CSS 4, Chart.js, Dagre.
• Performance: Multi-threaded generation with drift correction.
• Tooling: pnpm, Turborepo, Vitest, TypeScript.

Internal Documentation

• Backend details: apps/backend/README.md
• Frontend details: apps/frontend/README.md
• Test Consumer details: apps/test-consumer/README.md

License

Apache 2.0 — see LICENSE.