Trait RateMetric 

pub trait RateMetric: Send + Sync {
    // Required method
    fn remaining_ratio(&self) -> f64;
}

Exposes remaining capacity for quota-aware strategies. Higher is better.

Complementary to LoadMetric (which exposes current load — lower is better):

• LoadMetric: “how busy is this node?” → lower wins
• RateMetric: “how much capacity remains?” → higher wins

A node can implement both — a node may have low load but little remaining quota, or high load but ample quota.

Required Methods

fn remaining_ratio(&self) -> f64

Remaining capacity as a ratio: 0.0 = exhausted, 1.0 = fully available.

Implementors