Request
Route a client to the least-loaded healthy instance for a service.
Redirect mode (default)
curl -v http://localhost:8080/ms.auth/login
# HTTP/1.1 302 Found
# Location: http://10.0.0.5:3001/loginProxy mode (PROXY_MODE=true)
curl -v http://localhost:8080/ms.auth/login
# HTTP/1.1 200 OK
# <response from backend>Path
| Segment | Description |
|---|---|
ms.auth | Service name to discover |
/login | Path forwarded to the backend |
Response
| Mode | Status | Behaviour |
|---|---|---|
| Redirect (default) | 302 Found | Returns Location header pointing to the best instance |
Proxy (PROXY_MODE=true) | 200 OK (from backend) | Proxies the request and returns the backend response directly |
In proxy mode, flux adds X-Forwarded-For, X-Forwarded-Host, X-Forwarded-Proto, and X-Real-IP headers to the proxied request.
Selection Algorithm
flux selects the instance with the lowest active_connections among healthy instances (those whose TTL hasn’t expired).