Configure a Load Balancer

Networking Topology Diagram

A load balancer distributes incoming traffic across multiple backend servers, improving availability and scalability. LightYear's managed load balancer handles health checks, SSL termination, and session persistence automatically.

Prerequisites

• At least two running servers in the same region
• A LightYear account with load balancer access

Step 1 — Create a Load Balancer

1. Navigate to Networking → Load Balancers.
2. Click Create Load Balancer.
3. Select the region (must match your backend servers).
4. Choose a protocol: HTTP, HTTPS, or TCP.

Step 2 — Configure the Forwarding Rules

For HTTPS termination, upload your SSL certificate under SSL Certificates before creating the forwarding rule.

Step 3 — Add Backend Instances

1. Under Attached Instances, click Add Instance.
2. Select your backend servers from the dropdown.
3. Repeat for all backend servers.

Step 4 — Configure Health Checks

Health checks determine whether a backend is healthy and should receive traffic.

Create a health check endpoint on your backend servers:

$cat > /var/www/html/health << 'EOF'
$OK
$EOF

Or in your Node.js application:

app.get('/health', (req, res) => {
  res.status(200).json({ status: 'ok', timestamp: Date.now() });
});

Step 5 — Configure Session Persistence (Optional)

If your application requires users to always hit the same backend server, enable sticky sessions:

1. Under Sticky Sessions, select Cookie.
2. Set the cookie name (e.g., LB_SESSION).
3. Set the expiry in seconds (e.g., 3600 for 1 hour).

Step 6 — Verify the Load Balancer

After creation, the load balancer is assigned a public IP. Test it:

$curl -I http://LOAD_BALANCER_IP

HTTP/1.1 200 OK
Server: nginx/1.24.0
Content-Type: text/html; charset=utf-8

Configure via API

$curl -X POST https://api.lightyear.host/v1/load-balancers \
$  -H "Authorization: Bearer YOUR_API_KEY" \
$  -H "Content-Type: application/json" \
$  -d '{
$    "region": "sgp-01",
$    "label": "web-lb-01",
$    "forwarding_rules": [
$      {"frontend_protocol": "HTTP", "frontend_port": 80, "backend_protocol": "HTTP", "backend_port": 80}
$    ],
$    "health_check": {
$      "protocol": "HTTP",
$      "port": 80,
$      "path": "/health",
$      "check_interval": 15,
$      "response_timeout": 5,
$      "unhealthy_threshold": 3,
$      "healthy_threshold": 2
$    }
$  }'

[!TIP] Point your domain's DNS A record to the load balancer IP, not to individual server IPs. This allows you to add or remove backend servers without changing DNS.