Struct PeerLoadBalancer 

pub struct PeerLoadBalancer { /* private fields */ }

Peer-aware load balancer.

Distributes requests across known peers using a configurable PlbStrategy. Tracks health, latency, and in-flight requests per peer and recomputes normalised weights after every completed request.

Implementations

impl PeerLoadBalancer

pub fn new(config: PlbBalancerConfig) -> Self

Create a new balancer with the given configuration.

pub fn default_config() -> Self

Create a balancer with default configuration.

pub fn add_peer(&mut self, id: PlbPeerId, capacity: u32)

Register a new peer with the given capacity. If the peer already exists its capacity is updated.

pub fn remove_peer(&mut self, id: &PlbPeerId) -> Option<PlbPeerState>

Remove a peer from the balancer.

pub fn set_healthy( &mut self, id: &PlbPeerId, healthy: bool, ) -> Result<(), PlbError>

Manually override the health state of a peer.

pub fn cooldown_peer(&mut self, id: &PlbPeerId) -> Result<(), PlbError>

Put a peer in cooldown for config.cooldown_ms milliseconds.

pub fn select_peer(&mut self, key: &[u8]) -> Result<PlbPeerId, PlbError>

Select a peer for the next request.

key is used only by PlbStrategy::ConsistentHash; other strategies ignore it.

pub fn record_result( &mut self, peer_id: &PlbPeerId, latency_ms: f64, success: bool, ) -> Result<(), PlbError>

Record the outcome of a completed request.

Updates EWMA latency, success/failure counters and recomputes weights.

pub fn recompute_weights(&mut self)

Recompute normalised weights for all peers.

Weight formula per peer: w = capacity_score × latency_score × health_score

where:

• capacity_score = (capacity - in_flight) / capacity (0 if zero capacity)
• latency_score = 1 / (1 + avg_latency_ms / 1000)
• health_score = success_rate (1.0 for new peers with no history)

pub fn run_health_check(&mut self)

Evaluate all peers and mark unhealthy those whose failure rate exceeds 1 - health_threshold.

pub fn balancer_stats(&self) -> PlbBalancerStats

Return an aggregate snapshot of balancer statistics.

pub fn config(&self) -> &PlbBalancerConfig

Return the current configuration.

pub fn peer_count(&self) -> usize

Return the number of registered peers.

pub fn peer_state(&self, id: &PlbPeerId) -> Option<&PlbPeerState>

Retrieve state for a specific peer.