High-Performance Print Server

A robust Node.js/TypeScript print server designed for Windows Server environments, optimized to handle thousands of label print jobs across multiple printers with high throughput and reliability.

Features

• High Performance: Multi-worker clustering and concurrent job processing
• Queue Management: Priority-based job queue with automatic retry logic
• Printer Monitoring: Real-time printer health checks and status monitoring
• Windows Integration: Native Windows printer discovery and printing
• Type Safety: Full TypeScript implementation with strict typing
• Production Ready: Windows Service installation, logging, and monitoring

Architecture

┌─────────────────┐    ┌──────────────────┐    ┌─────────────────┐
│   API Layer     │────│   Print Service  │────│ Printer Service │
│ (Express/Routes)│    │   (Orchestrator) │    │ (Win Integration)│
└─────────────────┘    └──────────────────┘    └─────────────────┘
                              │
                        ┌──────────────────┐
                        │  Queue Service   │
                        │ (Priority Queue) │
                        └──────────────────┘

Quick Start

Prerequisites

• Node.js 18+
• Windows Server 2016+ or Windows 10+
• PowerShell 5.1+
• Administrator privileges for service installation

Installation

1. Clone and setup project:

   git clone <repository-url>
   cd high-performance-print-server
   npm install

2. Build the project:

   npm run build

3. Install as Windows Service (run as Administrator):

   .\scripts\install-service.ps1

4. Verify installation:

   # Check service status
   Get-Service PrintServer
   
   # Test health endpoint
   curl http://localhost:3000/health

Configuration

Environment variables can be set in the system or through the service configuration:

# Server Configuration
PORT=3000
HOST=0.0.0.0
WORKERS=4

# Security
ALLOWED_ORIGINS=http://localhost:3000,https://your-domain.com

# Logging
LOG_LEVEL=info

API Reference

Submit Print Job

POST /api/print/submit
Content-Type: application/json

{
  "printerName": "HP_LaserJet_Pro",
  "htmlContent": "PGh0bWw+PGJvZHk+PGgxPkxhYmVsPC9oMT48L2JvZHk+PC9odG1sPg==",
  "metadata": {
    "ageGroup": "adult",
    "priority": "high",
    "copies": 2,
    "paperSize": "A4",
    "orientation": "portrait"
  }
}

Response:

{
  "success": true,
  "data": {
    "jobId": "550e8400-e29b-41d4-a716-446655440000"
  },
  "message": "Print job submitted successfully"
}

Check Job Status

GET /api/print/status/{jobId}

Response:

{
  "success": true,
  "data": {
    "job": {
      "id": "550e8400-e29b-41d4-a716-446655440000",
      "status": "completed",
      "request": { /* original request */ },
      "startTime": 1640995200000,
      "endTime": 1640995205000
    }
  }
}

Get Server Metrics

GET /api/print/metrics

Response:

{
  "success": true,
  "data": {
    "metrics": {
      "totalJobs": 1250,
      "completedJobs": 1200,
      "failedJobs": 15,
      "averageProcessingTime": 2500,
      "queueLength": 35,
      "activePrinters": 47
    }
  }
}

Get Printer Status

GET /api/print/printers

Response:

{
  "success": true,
  "data": {
    "printers": [
      {
        "name": "HP_LaserJet_Pro",
        "status": "online",
        "jobsInQueue": 3,
        "lastJobTime": 1640995200000,
        "errorCount": 0
      }
    ]
  }
}

Performance Specifications

• Concurrent Jobs: Up to 50 simultaneous print jobs
• Queue Capacity: 10,000 jobs in memory
• Batch Processing: Configurable batch sizes (default: 10)
• Retry Logic: 3 automatic retries with exponential backoff
• Throughput: Designed for thousands of jobs per hour
• Memory Management: Automatic cleanup of completed jobs

Service Management

Start/Stop/Restart Service

# Start service
net start PrintServer

# Stop service
net stop PrintServer

# Restart service
net stop PrintServer && net start PrintServer

# Check status
Get-Service PrintServer

View Logs

# Service logs location
Get-Content "C:\PrintServer\logs\combined.log" -Tail 50

# Error logs
Get-Content "C:\PrintServer\logs\error.log" -Tail 20

Uninstall Service

# Run as Administrator
.\scripts\uninstall-service.ps1

Development

Local Development

# Development mode with hot reload
npm run dev

# Run tests
npm test

# Build TypeScript
npm run build

# Clean build directory
npm run clean

Project Structure

src/
├── config/          # Configuration management
├── middleware/      # Express middleware
├── routes/          # API route handlers
├── services/        # Core business logic
├── types/           # TypeScript type definitions
├── utils/           # Utility functions
└── server.ts        # Main server entry point

scripts/             # PowerShell deployment scripts
logs/               # Application logs
dist/               # Compiled JavaScript (build output)

Troubleshooting

Common Issues

Service won't start:

# Check if port is in use
netstat -ano | findstr :3000

# Check service logs
Get-EventLog -LogName Application -Source "PrintServer" -Newest 10

Printer not detected:

# List all printers
Get-Printer | Select-Object Name, PrinterStatus

# Check printer status
Get-Printer -Name "YourPrinterName"

Performance issues:

• Check server metrics: GET /api/print/metrics
• Monitor queue length and processing times
• Verify adequate system resources (CPU, memory)
• Consider increasing worker count in production

Log Levels

• error: Critical errors and failures
• warn: Warning conditions
• info: General information (default)
• debug: Detailed debugging information

Security Considerations

• Rate Limiting: 1000 requests per 15-minute window
• CORS: Configurable allowed origins
• Input Validation: Strict validation using Joi schemas
• Base64 Encoding: HTML content must be base64 encoded
• Service Account: Runs under Windows service account

License

[Your License Here]

Support

For issues and support:

1. Check the logs in logs/ directory
2. Review this documentation
3. Check Windows Event Logs for service-related issues
4. Verify printer connectivity and drivers