## Complete Observability Stack (O1-O13) Implements all 13 observability issues in a single PR. 119 metrics total. ### Commits (one per issue) | Issue | Title | Metrics | |-------|-------|---------| | **O10** | Prometheus metrics module + /metrics endpoint | Foundation | | **O1** | Instrument ingest handler | I1-I12 (12) | | **O2** | Instrument query handler | Q1-Q12 (12) | | **O3** | Instrument context endpoint | C1-C8 (8) | | **O4** | Relevance judge | R1-R9 (9) | | **O5** | Write volume + storage metrics | W1-W12 (12) | | **O6** | Pod resource observability | P1-P13 | | **O7** | Availability + dependency health | A1-A10 (10) | | **O8** | Ingest rate pattern tracking | IR1-IR10 (10) | | **O9** | Postgres internal observability | PG1-PG33 | | **O11** | Grafana dashboard | 12 panels | | **O12** | Prometheus alerting rules | 11 alerts | | **O13** | Relevance evaluation CronJob | K8s manifest | ### Key Changes - **metrics.rs**: Zero-dependency Prometheus metrics (Counter, Gauge, Histogram, Timer) - **GET /metrics**: Prometheus text exposition format endpoint - **Ingest/Query/Context handlers**: Instrumented with latency, errors, auth failures - **Health check**: DB dependency check with latency tracking - **Background task**: Periodic DB stats collection (entity/edge counts, pool stats) - **Relevance judge**: Threshold-based eval with precision/recall/F1 tracking - **Grafana dashboard**: 12 panels covering all metric groups - **Alert rules**: 11 PrometheusRule alerts (availability, latency, errors, quality) - **CronJob**: Periodic relevance evaluation with sample queries ### Testing - 506 tests passing (0 failures) - All metrics modules have unit tests - Relevance judge: 4 tests ### Deploy ```bash # Grafana dashboard kubectl apply -f k8s/infra/grafana-dashboard.json # Prometheus alerts kubectl apply -f k8s/infra/prometheus-alerts.yaml # Relevance eval CronJob kubectl apply -f k8s/infra/relevance-eval-cronjob.yaml ``` Closes #27 #28 #29 #30 #31 #32 #33 #34 #35 #36 #37 #38 #39 --------- Co-authored-by: rock <[email protected]> Reviewed-on: #52 Co-authored-by: poimen <[email protected]>