Sockudo

A high-performance, scalable WebSocket server implementing the Pusher protocol in Rust.

Star History

Features

• 🚀 High Performance - Handle 100K+ concurrent connections
• 🔄 Pusher Compatible - Drop-in replacement for Pusher services
• 🏗️ Scalable Architecture - Redis, Redis Cluster, NATS adapters
• 🛡️ Production Ready - Rate limiting, SSL/TLS, metrics
• ⚡ Async Cleanup - Non-blocking disconnect handling
• 📊 Real-time Metrics - Prometheus integration
• 🧠 Delta Compression + Conflation - Fossil and Xdelta3 (VCDIFF) with per-channel controls
• 🏷️ Tag Filtering - High-performance server-side filtering with optional tag emission controls
• 🌐 Native WebSocket Engine - sockudo_ws (replacing fastwebsockets) with advanced runtime tuning

What Was Added In This Branch

This branch includes a major realtime pipeline upgrade:

• Delta compression enhancements (including late-subscriber sync, cluster coordination, state cleanup hardening, and sequence/base-index improvements)
• Channel-level and global tag-filtering optimizations
• Conflation key support to isolate delta state per logical stream/key
• Broadcast and adapter path optimizations (lock/contention, batching, buffer controls)
• Expanded benchmark/soak tooling and test assets
• Full WebSocket transport migration from fastwebsockets to sockudo_ws
• Xdelta3 backend migration from xdelta3 crate to oxidelta

Delta Compression, Conflation, and Tag Filtering

Delta Algorithms

• fossil (fast, low overhead)
• xdelta3 (VCDIFF/RFC 3284) powered by oxidelta

Core Delta Options (config/config.json)

{
  "delta_compression": {
    "enabled": true,
    "algorithm": "Fossil",
    "full_message_interval": 10,
    "min_message_size": 100,
    "max_state_age_secs": 300,
    "max_channel_states_per_socket": 100,
    "max_conflation_states_per_channel": 100,
    "conflation_key_path": null,
    "cluster_coordination": true,
    "omit_delta_algorithm": true
  }
}

Tag Filtering (config/config.json)

{
  "tag_filtering": {
    "enabled": true,
    "enable_tags": false
  }
}

Channel-Level Delta Overrides

Per-app/per-channel overrides are available through channel_delta_compression in app config.
Supported modes include:

• Simple: inherit, disabled, fossil, xdelta3
• Full object settings: enabled, algorithm, conflation_key, max_messages_per_key, max_conflation_keys, enable_tags

Delta + Conflation Behavior

• Delta state is tracked per socket and channel
• Conflation key extraction isolates independent state streams (for example per asset, symbol, token id, etc.)
• Cluster coordination can synchronize full-message intervals across nodes (Redis/NATS)
• Cache-sync and late subscriber behavior were improved for reduced warm-up overhead

Detailed Docs

• DELTA_COMPRESSION.md
• docs/DELTA_COMPRESSION_BANDWIDTH_OPTIMIZATION.md
• docs/DELTA_COMPRESSION_CLUSTER_COORDINATION.md
• docs/DELTA_COMPRESSION_HORIZONTAL_IMPLEMENTATION.md
• docs/DELTA_COMPRESSION_LATE_SUBSCRIBERS.md
• docs/TAG_FILTERING.md
• docs/TAG_FILTERING_QUICKSTART.md

WebSocket Engine (sockudo_ws)

fastwebsockets was fully replaced with native sockudo_ws APIs:

• Axum integration via sockudo_ws::axum_integration::WebSocketUpgrade
• Split reader/writer model via sockudo_ws::axum_integration::WebSocket::{split}
• Message-based send/receive model (Text, Binary, Close, control handling)
• Native websocket runtime tuning mapped into websocket config

WebSocket Runtime Options (config/config.json)

{
  "websocket": {
    "max_messages": 1000,
    "max_bytes": 1048576,
    "disconnect_on_buffer_full": false,
    "max_message_size": 67108864,
    "max_frame_size": 16777216,
    "write_buffer_size": 16384,
    "max_backpressure": 1048576,
    "auto_ping": true,
    "ping_interval": 30,
    "idle_timeout": 120,
    "compression": "disabled"
  }
}

WebSocket Environment Variables

WEBSOCKET_MAX_MESSAGES=1000
WEBSOCKET_MAX_BYTES=1048576
WEBSOCKET_DISCONNECT_ON_BUFFER_FULL=false
WEBSOCKET_MAX_MESSAGE_SIZE=67108864
WEBSOCKET_MAX_FRAME_SIZE=16777216
WEBSOCKET_WRITE_BUFFER_SIZE=16384
WEBSOCKET_MAX_BACKPRESSURE=1048576
WEBSOCKET_AUTO_PING=true
WEBSOCKET_PING_INTERVAL=30
WEBSOCKET_IDLE_TIMEOUT=120
WEBSOCKET_COMPRESSION=disabled

Compression values for WEBSOCKET_COMPRESSION / websocket.compression:

• disabled
• dedicated
• shared
• window256b
• window1kb
• window2kb
• window4kb
• window8kb
• window16kb
• window32kb

Quick Start

Docker (Recommended)

# Clone and start with Docker Compose
git clone https://github.com/sockudo/sockudo.git
cd sockudo
make up

# Server runs on http://localhost:6001
# Metrics on http://localhost:9601/metrics

From Source

# Install Rust (if not already installed)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Build and run
git clone https://github.com/sockudo/sockudo.git
cd sockudo

# Fast local development build (default - no external dependencies)
cargo run --release

# Production build with all features
cargo run --release --features full

Feature Flags

Sockudo supports optional compilation of backends to speed up local development:

# Local development (fastest - default)
cargo build                                    # ~30-50% faster compile

# With specific backends
cargo build --features "redis,postgres"        # Redis + PostgreSQL
cargo build --features "redis-cluster,mysql"   # Redis Cluster + MySQL

# Full production build
cargo build --release --features full          # All backends

Available Features:

• local (default) - In-memory implementations only
• redis - Redis adapter, cache, queue, rate limiter
• redis-cluster - Redis Cluster support
• nats - NATS adapter
• mysql / postgres / dynamodb - Database backends
• sqs / lambda - AWS integrations
• full - All features enabled

Basic Usage

Connect using any Pusher-compatible client:

import Pusher from 'pusher-js';

const pusher = new Pusher('app-key', {
    wsHost: 'localhost',
    wsPort: 6001,
    cluster: '',
    forceTLS: false
});

const channel = pusher.subscribe('my-channel');
channel.bind('my-event', (data) => {
    console.log('Received:', data);
});

Configuration

Environment Variables

# Basic settings
PORT=6001
HOST=0.0.0.0
DEBUG=false

# Default app credentials
SOCKUDO_DEFAULT_APP_ID=app-id
SOCKUDO_DEFAULT_APP_KEY=app-key
SOCKUDO_DEFAULT_APP_SECRET=app-secret

# Scaling drivers
ADAPTER_DRIVER=redis          # local, redis, redis-cluster, nats
CACHE_DRIVER=redis           # memory, redis, redis-cluster, none
QUEUE_DRIVER=redis           # memory, redis, redis-cluster, sqs, none

Performance Tuning

# Connection limits
SOCKUDO_DEFAULT_APP_MAX_CONNECTIONS=100000
SOCKUDO_DEFAULT_APP_MAX_CLIENT_EVENTS_PER_SECOND=10000

# Cleanup performance (for handling mass disconnects)
CLEANUP_QUEUE_BUFFER_SIZE=50000
CLEANUP_BATCH_SIZE=25
CLEANUP_WORKER_THREADS=auto

# CPU scaling
ADAPTER_BUFFER_MULTIPLIER_PER_CPU=128

Database Pooling

• Global defaults (apply to all SQL DBs unless overridden):

DATABASE_POOLING_ENABLED=true
DATABASE_POOL_MIN=2
DATABASE_POOL_MAX=10
# Legacy cap if pooling disabled
DATABASE_CONNECTION_POOL_SIZE=10

• Per‑database overrides (take precedence over global when set):

# MySQL
DATABASE_MYSQL_POOL_MIN=4
DATABASE_MYSQL_POOL_MAX=32

# PostgreSQL
DATABASE_POSTGRES_POOL_MIN=2
DATABASE_POSTGRES_POOL_MAX=16

• config/config.json keys:

{
  "database_pooling": { "enabled": true, "min": 2, "max": 10 },
  "database": {
    "mysql": { "pool_min": 2, "pool_max": 10, "connection_pool_size": 10 },
    "postgres": { "pool_min": 2, "pool_max": 10, "connection_pool_size": 10 }
  }
}

Behavior:

• When database_pooling.enabled is true, managers use per‑DB pool_min/pool_max if provided; otherwise they fall back to the global database_pooling.min/max.
• When disabled, managers use connection_pool_size as the max connections for backward compatibility.

Deployment Scenarios

Scenario	CPU/RAM	Adapter	Cache	Queue	Max Connections
Development	1vCPU/1GB	local	memory	memory	1K
Small Production	2vCPU/2GB	redis	redis	redis	10K
High Traffic	4vCPU/4GB+	redis	redis	redis	50K+
Multi-Region	8vCPU/8GB+	redis-cluster	redis-cluster	redis-cluster	100K+

Architecture

┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
│   Load Balancer │────│   Sockudo Node  │────│   Redis Cluster │
│    (Nginx)      │    │    (Rust/Tokio) │    │  (State Store)  │
└─────────────────┘    └─────────────────┘    └─────────────────┘
         │                       │                       │
         │              ┌─────────────────┐             │
         └──────────────│   Sockudo Node  │─────────────┘
                        │    (Rust/Tokio) │
                        └─────────────────┘

Documentation

• Full Documentation - Complete setup and configuration guide
• Performance Tuning - Optimize for your workload
• Docker Deployment - Production-ready containers
• API Reference - WebSocket and HTTP API details

Testing

# Run all tests
make test

# Interactive WebSocket testing
cd test/interactive && npm install && npm start
# Open http://localhost:3000

# Load testing
make benchmark

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

Licensed under the MIT License.

Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Documentation: sockudo.io
• Discord: Join our Discord
• X: @sockudorealtime
• Email: sockudorealtime