Module qos 

Per-peer Quality-of-Service (QoS) tracking.

Every known Pouch in the network gets a PeerQos record that is updated whenever the local node issues a Ping challenge or a Proof-of-Storage challenge and receives (or times out on) a response.

Stability score

The stability score s ∈ [0.0, 1.0] summarises two independent signals:

s(p) = w_lat · latency_score(rtt_ewma) + w_rel · challenge_success_ewma

latency_score(rtt_ms) = exp(−rtt_ms / RTT_REF_MS)   (RTT_REF_MS = 500 ms)

Default weights: w_lat = 0.6, w_rel = 0.4.

EWMA smoothing

Signal	Factor	Rationale
RTT	α=0.125	TCP-standard (RFC 6298)
Challenge result	β=0.10	Slower decay → stable reliability view

A new peer starts with rtt_ewma_ms = None (latency component = 0) and challenge_success_ewma = 1.0 (benefit of the doubt, falls quickly on failure).

Structs

PeerQos

Live QoS data for a single remote Pouch peer.

QosRegistry

In-memory map of peer_id → PeerQos for the local node.

Constants

FAULT_BLACKLISTED

Fault score at which a peer is blacklisted — evicted from routing and announced as blacklisted on gossip.

FAULT_DEGRADED

Fault score (0–100) at which a peer is considered degraded — no new fragments will be assigned to it.

FAULT_SUSPECTED

Fault score at which a peer is suspected — preventive recoding begins.