Optimizing LocalTunnel Performance

While LocalTunnel is generally fast, there are several techniques you can use to optimize performance and reliability.

Understanding Performance Factors

Network Latency

• Distance to LocalTunnel servers
• Internet connection quality
• ISP routing efficiency

Local Server Performance

• Application response times
• Resource utilization
• Database query optimization

Tunnel Configuration

• Connection settings
• Request handling
• Error recovery

Optimization Techniques

1. Server-Side Optimizations

Enable Compression

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

Optimize Static Assets

// Serve static files efficiently
app.use('/static', express.static('public', {
  maxAge: '1d',
  etag: true
}));

Implement Caching

const mcache = require('memory-cache');

const cache = (duration) => {
  return (req, res, next) => {
    const key = '__express__' + req.originalUrl || req.url;
    const cached = mcache.get(key);

    if (cached) {
      res.send(cached);
      return;
    }

    res.sendResponse = res.send;
    res.send = (body) => {
      mcache.put(key, body, duration * 1000);
      res.sendResponse(body);
    };

    next();
  };
};

// Cache API responses for 5 minutes
app.get('/api/data', cache(300), (req, res) => {
  res.json(getData());
});

2. Connection Optimization

Use Keep-Alive Connections

const http = require('http');

const agent = new http.Agent({
  keepAlive: true,
  keepAliveMsecs: 30000,
  maxSockets: 50
});

Optimize Request Handling

// Increase request timeout
app.use((req, res, next) => {
  req.setTimeout(30000); // 30 seconds
  next();
});

3. LocalTunnel Configuration

Use Persistent Subdomains

# Consistent subdomain reduces DNS lookup time
lt --port 3000 --subdomain myapp-prod

Implement Reconnection Logic

const localtunnel = require('localtunnel');

async function createStableTunnel(options) {
  let tunnel;

  const connect = async () => {
    try {
      tunnel = await localtunnel(options);
      console.log('Tunnel created:', tunnel.url);

      tunnel.on('close', () => {
        console.log('Tunnel closed, reconnecting...');
        setTimeout(connect, 1000);
      });

      tunnel.on('error', (err) => {
        console.error('Tunnel error:', err);
        setTimeout(connect, 5000);
      });

    } catch (err) {
      console.error('Failed to create tunnel:', err);
      setTimeout(connect, 5000);
    }
  };

  await connect();
  return tunnel;
}

Monitoring Performance

1. Response Time Monitoring

app.use((req, res, next) => {
  const start = Date.now();

  res.on('finish', () => {
    const duration = Date.now() - start;
    console.log(`${req.method} ${req.url} - ${duration}ms`);

    // Alert on slow responses
    if (duration > 5000) {
      console.warn(`Slow response: ${req.url} took ${duration}ms`);
    }
  });

  next();
});

2. Request Volume Tracking

let requestCount = 0;
let lastReset = Date.now();

app.use((req, res, next) => {
  requestCount++;

  // Reset counter every minute
  if (Date.now() - lastReset > 60000) {
    console.log(`Requests per minute: ${requestCount}`);
    requestCount = 0;
    lastReset = Date.now();
  }

  next();
});

3. Memory Usage Monitoring

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

Database Optimization

Connection Pooling

const { Pool } = require('pg');

const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
  max: 20,
  idleTimeoutMillis: 30000,
  connectionTimeoutMillis: 2000,
});

Query Optimization

// Use prepared statements
const query = 'SELECT * FROM users WHERE id = $1';
const values = [userId];
const result = await pool.query(query, values);

Load Testing

Using Artillery

# artillery-config.yml
config:
  target: 'https://myapp.loca.lt'
  phases:
    - duration: 60
      arrivalRate: 10
scenarios:
  - name: "API Load Test"
    requests:
      - get:
          url: "/api/users"
      - post:
          url: "/api/users"
          json:
            name: "Test User"

Using curl for Quick Tests

# Test response time
time curl https://myapp.loca.lt/api/health

# Parallel requests
for i in {1..10}; do
  curl -s https://myapp.loca.lt/api/users &
done
wait

Performance Checklist

• [ ] Compression enabled
• [ ] Static assets optimized
• [ ] Database queries optimized
• [ ] Caching implemented
• [ ] Keep-alive connections used
• [ ] Response time monitoring active
• [ ] Memory usage tracked
• [ ] Load testing performed
• [ ] Reconnection logic implemented
• [ ] Error handling optimized

Common Performance Issues

1. Memory Leaks

• Use process managers like PM2
• Monitor memory usage
• Implement garbage collection tuning

2. Database Bottlenecks

• Add proper indexes
• Use connection pooling
• Implement query caching

3. Network Issues

• Test with different ISPs
• Use CDNs for static assets
• Implement retry logic

With these optimizations, your LocalTunnel setup will be fast and reliable!