CosmicClash/docs/MATCHMAKING-SLOs.md

Matchmaking launch SLOs

These are the measurable release gates for the Phase 8 control plane. All latency measurements use server-side monotonic timestamps and are labelled by region, playlist, build, transport and warm/cold capacity. A request or match is counted only after the corresponding terminal event is durably recorded.

SLO	Metric and denominator	Window / target	Owner	Alert threshold
Placement eligibility	max(predicted_rtt_ms) across all accepted players in a candidate	Every candidate; <=100 ms	Matcher	Any eligible candidate over 100 ms pages immediately and is rejected
Regional observed RTT	p95 of server-observed handshake/game RTT for connected assigned players	Rolling 1 h, per region; <=80 ms	Game-server + networking	15 min above 80 ms, or any region p95 above 100 ms for 5 min
Acceptance → assignment-ready	assignment_ready - unanimous_accept for accepted proposals with warm capacity	Rolling 1 h; p95 <=5 s, p99 <=10 s	Allocator	p95 >5 s for 10 min or p99 >10 s for 5 min
Assignment → successful connection	connected - assignment_published for assignments not cancelled by policy	Rolling 1 h; p95 <=5 s	Game-server lifecycle	p95 >5 s for 10 min or connection success <99% for 5 min
Allocation + durable result	completed matches with both successful allocation and durable result / matches requiring allocation	Rolling 24 h; >=99.9%	Allocator + maintenance	<99.95% warning; <99.9% pages and blocks release
Server tick health	Physics ticks completed without backlog / expected physics ticks; resource headroom is measured independently	Every live match; zero backlog and >=30% CPU/RSS headroom	Game-server	Any sustained backlog, or headroom <30% for 5 min
Control-plane API	p95 request latency for non-streaming authenticated API requests, excluding client cancellation	Rolling 5 min, by route; <=250 ms	API	p95 >250 ms for 5 min or 5xx >1%

Measurement rules

• Do not combine EU and NA into one percentile; a healthy region must not hide an unhealthy one.
• Exclude explicitly rejected requests from success denominators, but count accepted work that later expires, fails allocation, or loses result delivery.
• Preserve queue, proposal, match, server and request IDs on every metric and trace. Never attach Steam auth tickets, SDR relay tickets, publisher keys or other credentials to labels, logs or traces.
• Warm-capacity SLOs are evaluated only when the region has the declared Ready floor. Cold-start and capacity-exhaustion outcomes are separate dashboards, not silently removed from availability accounting.
• Alert thresholds page the owning role; the release gate is the stricter target in the table, not the warning threshold.

Release evidence

A release candidate must provide one complete 24-hour report, route-level API histograms, regional RTT histograms, allocation/connection cohort counts, tick-health samples, and an incident review for every SLO breach. Load and chaos tests must retain the same event IDs so the report can distinguish retryable control-plane delay, player no-show, and match-integrity failure.