fix(metrics): cap label cardinality — drop per-user views, *_created, raw-path leak - #179
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… raw-path leak Grafana Cloud free tier (10k series) was blown out at 14.5k+: - user_page_views_total + its _created twin were 12.9k series (88%) — username(286) x path. Dropped entirely along with the three dashboard panels that read it. - disable_created_metrics(): the OpenMetrics *_created companions doubled every counter/histogram and nothing read them (all "Unused" in the cardinality dashboard). - http_request_duration_seconds: method label removed (no dashboard queried it) + buckets 10 -> 6; ~1,260 series -> ~450. - Hardening: unmatched routes (bot POST probes) collapse to "(unmatched)" instead of minting a permanent series per raw URL; garbage verbs (PROPFIND, ...) collapse to OTHER; /class-icons/ joins the skip-list. Expected steady state ~1.5-2k active series. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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Summary
Grafana Cloud free tier (10k active series) was blown out at 14.5k+. Cardinality dashboard breakdown:
user_page_views_total+_createdtwin = 12,905 series (88%) —username(286 values) × path. Dropped entirely (metric, middleware, and the three dashboard panels that read it).disable_created_metrics()— the OpenMetrics*_createdcompanion series doubled every counter/histogram and nothing read them (all flagged "Unused").http_request_duration_seconds:methodlabel removed (no dashboard query used it) + buckets 10 → 6 — ~1,260 series → ~450.http_requests_totalunchanged.(unmatched)path label instead of minting a permanent series per raw URL; scanner verbs (PROPFIND, …) collapse toOTHER;/class-icons/added to the metrics skip-list.Expected steady state: ~1.5–2k active series (~15–20% of free tier) with growth vectors capped.
Test plan
tests/server/test_metrics.py: label normalisation (templates kept, unmatched/garbage collapsed), histogram has no method label, no*_createdin scrape output, static-mount skip-list.ops/grafana/dashboards/frontend.jsonvalidated as JSON (6 panels remain).🤖 Generated with Claude Code