Struct UpstreamPool 

pub struct UpstreamPool {
    pub backends: Vec<Backend>,
    pub client: Client<HttpsConnector<HttpConnector>, Body>,
    pub healthy: Vec<AtomicBool>,
    pub active_conns: Vec<AtomicUsize>,
    pub max_connections: Option<usize>,
}

Pool of upstream backends with a shared HTTP client, health status, and active-connection counters.

Fields

backends: Vec<Backend>

client: Client<HttpsConnector<HttpConnector>, Body>

healthy: Vec<AtomicBool>

Per-backend health flag. true = healthy, false = unhealthy.

active_conns: Vec<AtomicUsize>

Per-backend active connection count (used by LeastConn).

max_connections: Option<usize>

Optional total connection limit across all backends.

Implementations

impl UpstreamPool

pub fn from_config(config: &ProxyConfig) -> Self

pub fn is_healthy(&self, idx: usize) -> bool

Returns true if the backend at idx is currently marked healthy.

pub fn set_healthy(&self, idx: usize, val: bool)

Mark a backend as healthy or unhealthy.

pub fn acquire_conn(&self, idx: usize) -> ConnGuard<'_>

Increment the active connection count for a backend. Returns a guard that decrements on drop.

pub fn conn_count(&self, idx: usize) -> usize

Get the current active connection count for a backend.

pub fn total_active_conns(&self) -> usize

Total active connections across all backends.

pub fn len(&self) -> usize

Number of backends.

pub fn is_empty(&self) -> bool

Whether the pool has no backends.