Module strategy 

Load balancing strategies and the Strategy trait.

Built-in strategies:

Strategy	Requires	Algorithm
RoundRobin	—	Sequential cycling
WeightedRoundRobin	Weighted+Node	Nginx smooth weighted round-robin
Random	—	Uniform random
WeightedRandom	Weighted	Proportional random
LeastLoad	LoadMetric	Pick lowest load_score()
PowerOfTwoChoices	LoadMetric	Random 2, pick lower load
ConsistentHash	Node	Virtual-node ring (cached)
MostAvailable	RateMetric	Pick highest remaining, epsilon tie-break

Combinators: WithFallback, FallbackChain.

Structs

ConsistentHash

Consistent hashing with virtual nodes.

FallbackChain

Tries each strategy in order until one returns a result.

LeastLoad

Selects the node with the lowest load score.

MostAvailable

Selects the node with the most remaining capacity, with epsilon tie-breaking.

PowerOfTwoChoices

Power of Two Choices: randomly pick two nodes, select the one with lower load.

Random

Uniform random selection.

RoundRobin

Simple round-robin: cycles through candidates sequentially.

SelectionContext

Context provided to strategies during node selection.

SelectionContextBuilder

Use builder syntax to set the required parameters and finish by calling the method Self::build().

WeightedRandom

Weighted random selection. Nodes with higher weight are proportionally more likely.

WeightedRoundRobin

Smooth weighted round-robin (Nginx-style).

WithFallback

Tries the primary strategy first, falls back to secondary if primary returns None.

Traits

Strategy

A load balancing strategy that selects a node from a list of candidates.