KoaVM
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Guide · For customers

Load balancers

A load balancer receives traffic on a public address and splits it between your VPSs, checking that they answer: if a VPS stops, traffic goes to the others until it comes back. For websites it requests the HTTPS certificate from Let's Encrypt by itself and renews it.

You find it on the Load balancers page, if your service includes it.

Creating one

New load balancer: name, location (better close to your VPSs), what it receives and the VPSs.

  • Website: HTTPS on port 443 with the certificate for the domains you write; port 80 redirects to HTTPS.
  • HTTP: no certificate, for example behind another proxy.
  • TCP: any service (databases, mail, games…), with the ports you choose.

In 2–4 minutes it's ready and you see its IP. Then point the domains to that IP: the certificate arrives by itself as soon as the panel sees they point there. Meanwhile HTTPS answers with a temporary certificate.

The load balancer page

  • Services: the listening ports. For each one choose port, VPS port, the check (TCP, or an HTTP page that must answer 2xx or 3xx), the certificate (Let's Encrypt or your own, pasted with the private key), whether the same visitor stays on the same VPS and, for TCP, the PROXY protocol. Up to 10 services.
  • VPSs: up to 50. For each VPS you see whether it answers each service and how it's reached: on the private network (better) or on the public IP. To go over the private network, connect the VPS to the same network as the load balancer (VPS page › Private networks).
  • Name and algorithm: round robin fits almost always; fewest connections for long connections; same visitor, same VPS keeps each IP on the same VPS.
  • Delete: confirm by typing the name. The IP is released, the VPSs stay.

Your VPSs see the visitor's IP in the X-Forwarded-For header (HTTP and HTTPS) or with the PROXY protocol (TCP, if you turn it on). If a VPS has the firewall on and is reached on the public IP, open the port for the load balancer IP.

Team and API

The owner and the team administrators create and delete load balancers; technicians edit them. With an API key: GET/POST /load-balancers and GET/PUT/DELETE /load-balancers/{id} (see Team and API).