Architecture
AnchorPoint has three parts:
- Node plugin on every Paper server. Sends a heartbeat every two seconds with player count, TPS and role.
- Velocity plugin. When a player connects or leaves a game, it asks the coordinator where to send them.
- Coordinator, the AnchorPoint backend (us-east). Keeps the live view of the cluster and runs the balancer.
Balancer
Section titled “Balancer”The default least-loaded strategy picks the lobby with the lowest players / max-players in the
player’s region. A lobby above soft-cap (0.85 by default) is only picked when every lobby in the
region is above it.
| Strategy | Picks |
|---|---|
least-loaded |
Lowest fill ratio |
fill-first |
Highest fill ratio below the soft cap, keeps lobbies lively at low player counts |
sticky |
The lobby the player was on last, if it is up and below the cap |
When the coordinator is down
Section titled “When the coordinator is down”Velocity keeps the last known cluster view for 60 seconds and balances on it. After that it falls back
to the try list in velocity.toml, as if AnchorPoint were not installed.
A node that stops sending heartbeats is marked down after six seconds. Since 3.1.2 a node that restarts quickly is not left stale.