Performance Optimization

Performance Optimization

Optimize Pocat for better performance, faster downloads, and improved scalability.

Download Performance

Choose the Right Downloader

yt-dlp (Recommended):

• 95%+ success rate
• Fastest downloads
• Best format selection

{
  "youtubeUrl": "URL",
  "downloader": "yt-dlp"
}

Optimize Quality Settings

Balance quality vs speed:

{
  "quality": "720p"  // Good balance
}

Quality performance comparison:

• 144p: ~10MB, fastest download
• 360p: ~25MB, good for mobile
• 720p: ~130MB, recommended default
• 1080p: ~330MB, high quality
• 4K: ~2GB, slowest but best quality

Concurrent Downloads

Limit concurrent downloads:

const maxConcurrent = 3;
const downloadQueue = [];

async function processQueue() {
  const batch = downloadQueue.splice(0, maxConcurrent);
  await Promise.all(batch.map(download));
}

Server Performance

Memory Optimization

Node.js memory settings:

# Increase heap size
node --max-old-space-size=4096 server.js

# Enable garbage collection optimization
node --optimize-for-size server.js

Monitor memory usage:

setInterval(() => {
  const used = process.memoryUsage();
  console.log('Memory usage:', {
    rss: Math.round(used.rss / 1024 / 1024) + 'MB',
    heapUsed: Math.round(used.heapUsed / 1024 / 1024) + 'MB'
  });
}, 30000);

CPU Optimization

Use clustering:

const cluster = require('cluster');
const numCPUs = require('os').cpus().length;

if (cluster.isMaster) {
  for (let i = 0; i < numCPUs; i++) {
    cluster.fork();
  }
} else {
  // Start your app
  require('./server.js');
}

Database Performance

SQLite optimizations:

-- Enable WAL mode
PRAGMA journal_mode=WAL;

-- Increase cache size
PRAGMA cache_size=10000;

-- Optimize for speed
PRAGMA synchronous=NORMAL;

Add database indexes:

CREATE INDEX idx_projects_status ON projects(status);
CREATE INDEX idx_projects_created_at ON projects(created_at);

Network Performance

Enable Compression

const compression = require('compression');
app.use(compression());

Implement Caching

Response caching:

const cache = new Map();

app.get('/api/projects/:id', (req, res) => {
  const cacheKey = `project_${req.params.id}`;

  if (cache.has(cacheKey)) {
    return res.json(cache.get(cacheKey));
  }

  // Fetch data and cache it
  const data = fetchProject(req.params.id);
  cache.set(cacheKey, data);
  res.json(data);
});

Rate Limiting

Implement smart rate limiting:

const rateLimit = require('express-rate-limit');

const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100, // limit each IP to 100 requests per windowMs
  message: 'Too many requests, please try again later'
});

app.use('/api/', limiter);

File System Performance

Storage Optimization

Use SSD storage for better I/O:

• Store downloads on SSD
• Use separate disk for database
• Implement file cleanup policies

File cleanup automation:

const cron = require('node-cron');

// Clean up files older than 7 days
cron.schedule('0 2 * * *', () => {
  const sevenDaysAgo = Date.now() - (7 * 24 * 60 * 60 * 1000);

  fs.readdir('downloads/', (err, files) => {
    files.forEach(file => {
      fs.stat(`downloads/${file}`, (err, stats) => {
        if (stats.mtime.getTime() < sevenDaysAgo) {
          fs.unlink(`downloads/${file}`, () => {});
        }
      });
    });
  });
});

Streaming Downloads

Stream large files:

app.get('/download/:id', (req, res) => {
  const filePath = `downloads/project_${req.params.id}.mp4`;
  const stat = fs.statSync(filePath);

  res.writeHead(200, {
    'Content-Type': 'video/mp4',
    'Content-Length': stat.size,
    'Accept-Ranges': 'bytes'
  });

  const stream = fs.createReadStream(filePath);
  stream.pipe(res);
});

Monitoring & Metrics

Performance Monitoring

const performanceMonitor = {
  downloadTimes: [],
  apiResponseTimes: [],

  recordDownload(duration) {
    this.downloadTimes.push(duration);
    if (this.downloadTimes.length > 100) {
      this.downloadTimes.shift();
    }
  },

  getAverageDownloadTime() {
    return this.downloadTimes.reduce((a, b) => a + b, 0) / this.downloadTimes.length;
  }
};

Health Checks

app.get('/health', (req, res) => {
  const health = {
    status: 'ok',
    timestamp: new Date().toISOString(),
    uptime: process.uptime(),
    memory: process.memoryUsage(),
    downloads: {
      active: getActiveDownloads(),
      completed: getCompletedDownloads(),
      failed: getFailedDownloads()
    }
  };

  res.json(health);
});

Production Optimizations

Environment Configuration

NODE_ENV=production
NODE_OPTIONS="--max-old-space-size=4096"
UV_THREADPOOL_SIZE=16

Process Management

PM2 configuration:

ecosystem.config.js

module.exports = {
  apps: [{
    name: 'pocat',
    script: './server.js',
    instances: 'max',
    exec_mode: 'cluster',
    env: {
      NODE_ENV: 'development'
    },
    env_production: {
      NODE_ENV: 'production',
      PORT: 3333
    }
  }]
};

Load Balancing

Nginx configuration:

upstream pocat_backend {
    server 127.0.0.1:3333;
    server 127.0.0.1:3334;
    server 127.0.0.1:3335;
}

server {
    location / {
        proxy_pass http://pocat_backend;
    }
}

Benchmarking

Performance Testing

# Install Apache Bench
sudo apt install apache2-utils

# Test API performance
ab -n 1000 -c 10 http://localhost:3333/api/health

# Test download endpoint
ab -n 100 -c 5 -p post_data.json -T application/json http://localhost:3333/v2/projects

Monitoring Tools

• PM2 Monitor: pm2 monit
• htop: System resource monitoring
• iotop: Disk I/O monitoring
• New Relic: Application performance monitoring