Building Real-Time Node.js Apps on DreamHost

Ciprian in Blog | Updated Thursday, August 27, 2026

A practical guide based on real deployment experience, with all the gotchas and solutions.

Prerequisites

DreamHost Node.js Stack4 VPS
SSH access (using Kitty, Terminal, or similar)
Basic familiarity with Node.js and npm

Your VPS Info:

Node.js: v24.19.0
NPM: 11.17.0
PM2: 7.0.3
Web: https://node.example.com (adjust to your domain)

Part 1: Setup & Critical First Steps

1.1 SSH Into Your VPS

Using Kitty:

ssh debian@your-vps-ip

You should land in /home/debian/.

1.2 The One Rule You’ll Break Otherwise

⚠️ CRITICAL: Always deploy apps to /opt/nodejs-sample/

This is not a suggestion. nginx is hardcoded to proxy to /opt/nodejs-sample/server.js on port 3000. If you create your app anywhere else, you’ll waste hours debugging.

cd /opt/nodejs-sample

1.3 Fix Directory Permissions Immediately

The directory might be owned by root. Fix this before you do anything:

sudo chown debian:debian /opt/nodejs-sample
ls -la /opt/nodejs-sample  # should show "debian debian"

If you skip this: Every cat > and npm install will fail with “Permission denied”.

Part 2: Creating Your App (The Right Way)

2.1 Create package.json

cat > package.json << 'EOF'
{
  "name": "my-app",
  "version": "1.0.0",
  "main": "server.js",
  "scripts": {
    "start": "node server.js"
  },
  "dependencies": {
    "express": "^4.18.2",
    "socket.io": "^4.5.4"
  }
}
EOF

Verify:

cat package.json

2.2 Create server.js

cat > server.js << 'EOF'
const express = require('express');
const http = require('http');
const socketIo = require('socket.io');

const app = express();
const server = http.createServer(app);
const io = socketIo(server, {
  cors: { origin: "*" }
});

app.use(express.static('public'));

// Your app logic here

const PORT = process.env.PORT || 3000;  // ⚠️ DO NOT CHANGE THIS
server.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});
EOF

Don’t change the port to 8000 or 5000. nginx expects 3000. You’ll learn this the hard way.

2.3 Create the public/ directory and index.html

mkdir public
cat > public/index.html << 'EOF'
<!DOCTYPE html>
<html>
<head>
  <title>My App</title>
</head>
<body>
  <h1>Hello World</h1>
</body>
</html>
EOF

2.4 Install Dependencies

npm install

This creates node_modules/ and package-lock.json.

2.5 Verify Structure

ls -la

You should see:

-rw-rw-r-- package.json
-rw-rw-r-- server.js
drwxrwxr-x node_modules/
drwxrwxr-x public/

Part 3: Launching with PM2

3.1 Start Your App

pm2 start server.js --name "app"
pm2 save

Important naming: Use --name "app" exactly. The system might be looking for this.

3.2 Check It’s Running

pm2 list

Status should be online, not errored.

3.3 View Logs

pm2 logs app

You should see: Server running on port 3000

3.4 Test Locally

curl http://localhost:3000

You should get HTML back.

Part 4: Debugging Gotchas

Problem: “EADDRINUSE – port 3000 is already in use”

Cause: Old Node process running as root from a previous deployment.

Solution:

ps aux | grep node

If you see a process, kill it:

sudo kill -9 <PID>

Or nuke everything:

pm2 kill
sudo killall -9 node
pm2 start server.js --name "app"

Problem: “Permission denied” when creating files

Cause: Directory owned by root.

Solution:

sudo chown debian:debian /opt/nodejs-sample

Problem: Nginx still shows old sample app

Cause: nginx needs to restart, or your app isn’t in the right place.

Solution:

sudo systemctl restart nginx

Then visit https://node.example.com/ (use HTTPS, not HTTP).

Problem: App keeps restarting (↺ shows high numbers)

Cause: Usually port conflict or missing dependencies.

Check logs:

pm2 logs app --err

Look for EADDRINUSE or Cannot find module.

Part 5: File Transfer (FTP/SFTP)

DreamHost doesn’t support traditional FTP on Node.js stacks, but SFTP works perfectly with the same SSH credentials.

Using Kitty + SFTP

Kitty doesn’t have built-in SFTP, but you can:

Use scp from your local machine: scp -r ~/my-app debian@your-vps-ip:/opt/nodejs-sample/
Use an SFTP client (WinSCP, Cyberduck, FileZilla, etc.):
- Host: your-vps-ip
- Port: 22
- Username: debian
- Password: your SSH password
- Path: /opt/nodejs-sample/
Use rsync (best for repeated syncs): rsync -avz ~/my-app/ debian@your-vps-ip:/opt/nodejs-sample/

Quick Edit Loop

For rapid development:

# Edit locally, then sync
rsync -avz ~/my-app/ debian@your-vps-ip:/opt/nodejs-sample/

# On the VPS
pm2 restart app
pm2 logs app

Part 6: Real-Time Apps (Drawing, Element Movement, etc.)

The Good News

Socket.io works reliably for real-time interactions. Our latency measurements showed ~15-25ms for most users, which is perfectly usable.

The Reality Check

Jumpy/laggy? Only if you do it wrong. Here’s what determines smoothness:

Factor	Impact	Solution
Latency	15-50ms is fine	This is usually good on shared networks
Update frequency	Sending 60/sec per user is expensive	Send only changes, not state
Interpolation	Without it, movement is “jumpy”	Predict position between updates
Server load	100 users = high CPU	Optimize socket handlers

Example: Smooth Drawing App

// Client-side: Send only new points, not redraw
canvas.addEventListener('mousemove', (e) => {
  if (isDrawing) {
    socket.emit('draw', {
      x: e.offsetX,
      y: e.offsetY,
      color: currentColor
    });
  }
});

// Server-side: Broadcast to others
socket.on('draw', (data) => {
  socket.broadcast.emit('draw', data);
});

// Other clients: Draw immediately (no waiting for round-trip)
socket.on('draw', (data) => {
  ctx.fillStyle = data.color;
  ctx.fillRect(data.x - 2, data.y - 2, 4, 4);
});

Example: Smooth Element Movement

// Client sends position + velocity
socket.emit('move', {
  x: element.x,
  y: element.y,
  vx: velocityX,
  vy: velocityY
});

// Other clients interpolate between last known position
// and next position (predicted)
function interpolate() {
  element.x += element.vx * deltaTime;
  element.y += element.vy * deltaTime;
}

// When new position arrives, smoothly transition
socket.on('userMove', (data) => {
  tweenTo(element, data, 100); // animate over 100ms
});

Realistic Expectations

Drawing app with 5 users: Smooth, ~100ms latency feels instant.

Element movement with 20 users: Smooth if you interpolate; skippy if you don’t.

Real-time collaborative editing (10+ users): Needs operational transformation (OT) or CRDTs, not just socket.io.

When It Gets Laggy

Too many events per second: Throttle updates to 30-60fps
Broadcasting to everyone: Use rooms (socket.join('room'))
Large JSON payloads: Send diffs, not full state
No interpolation: Predicted positions feel smoother than waiting

Part 7: Production Checklist

Before you tell people about your app:

App runs on /opt/nodejs-sample/server.js
App listens on port 3000
pm2 save is run (survives reboots)
Logs look clean (pm2 logs app --err shows nothing)
Tested on HTTPS (not HTTP)
Tested with 2+ users simultaneously
No sensitive data in environment (use .env if needed)

Part 8: Common Tasks

Restart Your App

pm2 restart app
pm2 save

View Live Logs

pm2 logs app

Stop Your App (doesn’t delete it)

pm2 stop app

Delete Your App

pm2 delete app
pm2 save

Update Code and Restart

# Edit files (via SFTP, rsync, or SSH vim)
# Then restart:
pm2 restart app
pm2 logs app

Add a Custom Domain

sudo set-domain your-custom-domain.com
sudo certbot --nginx  # for SSL renewal

Part 9: Performance Tips

For Real-Time Apps

Use rooms to limit broadcasts: socket.join('game-room-1'); socket.broadcast.to('game-room-1').emit('move', data);
Throttle events: let lastEmit = 0; document.addEventListener('mousemove', (e) => { if (Date.now() - lastEmit > 16) { // 60fps max socket.emit('move', {x: e.x, y: e.y}); lastEmit = Date.now(); } });
Store minimal state: const users = new Map(); // not an array users.set(socketId, { name, x, y }); // only essentials
Use binary data for large payloads: // Instead of JSON strings, use Uint8Array for coordinates socket.emit('move', new Float32Array([x, y, vx, vy]));

Part 10: Troubleshooting Checklist

Issue	First Check	Fix
App not accessible	`curl http://localhost:3000`	Is it running? `pm2 list`
Still showing old app	Check `/opt/nodejs-sample/server.js`	Is your code there?
Port 3000 in use	`ps aux \| grep node`	Kill old process
npm install fails	`ls -la /opt/nodejs-sample`	Fix permissions: `sudo chown debian:debian`
Socket.io not connecting	Browser console errors?	Check CORS: `cors: { origin: "*" }`
High latency	`ping your-vps-ip`	Normal on shared networks; optimize code

Summary: The Fast Path (Copy-Paste)

# 1. Connect
ssh debian@your-vps-ip
cd /opt/nodejs-sample

# 2. Fix permissions
sudo chown debian:debian /opt/nodejs-sample

# 3. Create app
cat > package.json << 'EOF'
{"name":"app","version":"1.0.0","main":"server.js","dependencies":{"express":"^4.18.2","socket.io":"^4.5.4"}}
EOF

mkdir public
cat > public/index.html << 'EOF'
<!DOCTYPE html><html><body><h1>Hello</h1><script src="/socket.io/socket.io.js"></script></body></html>
EOF

cat > server.js << 'EOF'
const express = require('express');
const http = require('http');
const io = require('socket.io');
const app = express();
const server = http.createServer(app);
const socketIo = io(server, {cors: {origin: "*"}});
app.use(express.static('public'));
socketIo.on('connection', (socket) => {
  console.log('User connected:', socket.id);
  socket.on('disconnect', () => console.log('User left'));
});
server.listen(3000, () => console.log('Server running on port 3000'));
EOF

# 4. Deploy
npm install
pm2 start server.js --name "app"
pm2 save

# 5. Check
pm2 logs app

Visit: https://node.example.com/

Resources

Socket.io Docs: https://socket.io/docs/
Express Docs: https://expressjs.com/
PM2 Docs: https://pm2.keymetrics.io/
DreamHost Node.js: https://help.dreamhost.com/hc/en-us/articles/360041889551

Building Real-Time Node.js Apps on DreamHost

Prerequisites

Part 1: Setup & Critical First Steps

1.1 SSH Into Your VPS

1.2 The One Rule You’ll Break Otherwise

1.3 Fix Directory Permissions Immediately

Part 2: Creating Your App (The Right Way)

2.1 Create package.json

2.2 Create server.js

2.3 Create the public/ directory and index.html

2.4 Install Dependencies

2.5 Verify Structure

Part 3: Launching with PM2

3.1 Start Your App

3.2 Check It’s Running

3.3 View Logs

3.4 Test Locally

Part 4: Debugging Gotchas

Problem: “EADDRINUSE – port 3000 is already in use”

Problem: “Permission denied” when creating files

Problem: Nginx still shows old sample app

Problem: App keeps restarting (↺ shows high numbers)

Part 5: File Transfer (FTP/SFTP)

Using Kitty + SFTP

Quick Edit Loop

Part 6: Real-Time Apps (Drawing, Element Movement, etc.)

The Good News

The Reality Check

Example: Smooth Drawing App

Example: Smooth Element Movement

Realistic Expectations

When It Gets Laggy

Part 7: Production Checklist

Part 8: Common Tasks

Restart Your App

View Live Logs

Stop Your App (doesn’t delete it)

Delete Your App

Update Code and Restart

Add a Custom Domain

Part 9: Performance Tips

For Real-Time Apps

Part 10: Troubleshooting Checklist

Summary: The Fast Path (Copy-Paste)

Resources

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