Adds four metrics surfaced via the existing /metrics endpoint:
- overpass_cache_events_total{result=hit|miss|coalesced}
- overpass_cache_size (gauge)
- overpass_upstream_duration_seconds (histogram)
- overpass_upstream_requests_total{status} — covers 2xx/4xx/5xx and
an explicit "error" label for network-level failures
Grafana dashboards/planner.json gets a new row:
- Upstream health (5m 2xx success ratio, red <90%, green >99%)
- Cache hit ratio
- Cache size
- Upstream p95 latency
Plus timeseries panels for cache event breakdown, upstream status
over time, and p50/p95/p99 upstream latency.
The success-rate formula uses clamp_min(..., 1) on the denominator so
it doesn't NaN when traffic is zero.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Vite's dev server can re-evaluate modules, causing prom-client
"already registered" errors for all metrics, not just default ones.
Use getOrCreate pattern to reuse existing metrics from the registry.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Importing metrics.server.ts from yjs-server.ts caused
collectDefaultMetrics() to re-register during HMR, crashing
the planner dev server. Check if metrics already exist first.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Health endpoints:
- /api/health (Journal) and /health (Planner) with DB connectivity check
- Docker healthchecks updated to use app health endpoints
Structured logging:
- Pino with JSON output in production, pretty-print in dev
- Request logging middleware in Planner (method, path, status, duration)
- Replaced console.log/error with structured logger in email and auth flows
Prometheus metrics:
- prom-client with default Node.js metrics + custom histograms/gauges
- /metrics endpoints on both apps
- http_request_duration, planner_active_sessions, brouter_request_duration
Monitoring stack:
- Prometheus, Loki, Grafana containers in docker-compose
- Grafana provisioned with datasources, dashboards, and alert rules
- Caddy access logging (JSON to stdout for Loki)
- grafana.trails.cool with basic auth via Caddy
Dashboards and alerting:
- Overview: request rate, error rate, latency p50/p95/p99
- Planner: active sessions, connected clients, BRouter latency
- Infrastructure: memory, CPU, event loop lag
- Alerts: disk >80%, app down 2min, error rate >5%
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
