Module adaptive_lookup 

Adaptive Kademlia lookup scheduler that tunes alpha (parallelism) based on observed latency.

Overview

Kademlia’s alpha parameter controls how many concurrent RPCs are issued per lookup iteration. The standard value is 3, but a static setting is suboptimal:

• A congested network benefits from lower alpha so that fewer in-flight requests compete for the same scarce bandwidth.
• A fast network with low latency can sustain higher alpha, reducing total lookup latency through more parallelism.

This module provides:

• AdaptiveLookupScheduler — adjusts alpha in [1, 8] based on a rolling p90 latency window.
• PeerLatencyTracker — per-peer latency tracking with median-based ranking.
• LookupSchedulerStats — snapshot statistics (no atomics, clone-friendly).

Structs

AdaptiveLookupScheduler

Maintains a rolling latency window and adaptively tunes Kademlia alpha.

LookupSchedulerStats

Point-in-time snapshot of AdaptiveLookupScheduler state.

PeerLatencyTracker

Tracks per-peer latency with sliding windows and enables peer ranking.

Constants

ALPHA_DEFAULT

Default parallelism degree (standard Kademlia value).

ALPHA_MAX

Maximum parallelism degree for Kademlia lookups.

ALPHA_MIN

Minimum parallelism degree for Kademlia lookups.