Floating IPs and load balancers
Most apps are reached through a hostname, which the realm’s front door serves over HTTPS (Apps). For anything else, such as a game server, a database you open to the world, or a protocol that isn’t HTTP, give the workload a public address of its own.
You find all three kinds in Networks › Public IPs. They need your operator to have set up gateways and an address pool first; until then the tab says “Not set up here yet”.
Floating IPs
A floating IP is a public address you hold. Point it at one app or machine, and traffic to it reaches the workload, whichever server it runs on. It follows the workload when it moves.
- Choose New floating IP. Velrix takes an address from the pool for you.
- Choose Attach and pick the workload.
- Connect to the address. The workload’s own outbound connections also leave from it, even with internet access off.
Detach takes it off the workload and you keep it. Release gives it back to the pool, where it may go to someone else. How many you may hold is a limit your operator sets.
Security groups still apply: a floating IP only brings traffic to the workload’s network card, and its groups decide what gets in.
Public IPv6
Where your operator has an IPv6 pool, Add public IPv6 gives an app or a machine its own public IPv6 address, routed straight to it with no address translation. The workload is restarted with the address. Remove restarts it without and gives the address back.
Load balancers
A load balancer is one public address in front of an app, spread over the app’s healthy copies.
- Choose New load balancer, give it a name and pick the app. It gets an address of its own.
- It listens on the app’s protocols that are carried by port: add or change them on the app’s page under Settings › Protocols. A balancer with nothing to carry says so.
- Scale the app to several copies. Each copy that runs and isn’t unhealthy takes traffic; Health shows how many are healthy.
A copy that fails its health check stops taking new connections within seconds, and is taken back when it is healthy again. When no copy is healthy, connections are refused. An app that sleeps is woken by the first connection, which waits while it starts.
Rename changes only the name. Delete gives the address back to the pool.
Gateways
Floating IPs and load balancers live on the realm’s gateways: servers your operator picks to hold public addresses. One is active; when it goes silent, the next takes over within seconds and announces the addresses.
At launch, floating IPs and load balancers translate addresses without keeping connection state on the gateway, and each balancer spreads connections with its own consistent-hashing table (Maglev). So established connections survive a gateway failover: the next gateway sends them to the same copy. The gateway also defends balanced apps against SYN floods.