server-selection

This attribute determines how Radiator selects a RADIUS backend server when multiple server blocks are configured. Possible values are:

• fallback: Servers are tried in priority order. The highest-priority available server receives every request. Lower-priority servers are used only when higher-priority servers are unavailable or degraded.
• round-robin: Requests are distributed across all available servers in rotation. If a server fails, the next available server in the rotation is used.
• no-fallback: Only the highest-priority available server is tried for each request. If the operation fails on that server, the request fails without retrying on other servers.
• least-connections: Not currently supported for RADIUS backends. If configured, falls back to round-robin.

Default: fallback

Example configuration:

radius "EXAMPLE-SERVER" {
    server-selection round-robin;

    server "PRIMARY" {
        secret "mysecret";
        connect { protocol udp; host "192.168.1.10"; port 1812; }
    }

    server "SECONDARY" {
        secret "mysecret";
        connect { protocol udp; host "192.168.1.11"; port 1812; }
    }
}

See Backend Load Balancing for more details and examples.