"Tempo"
- LGTM Stack 組合運維：Loki + Grafana + Tempo + Mimir
說明 Grafana Stack 四個元件的責任分工、部署模式、常見故障與 dashboard provisioning
- Datadog → Grafana Stack：把 $50K/month bill 拆解到 self-hosted observability
Datadog 五層計費（host APM / metric / log ingest / log retention / RUM）拆解、對位 Grafana Stack（Mimir / Loki / Tempo / Grafana / Alloy）的 5 層責任；OTel-based agent migration、5 個 production 踩雷（cardinality 爆 / log volume cost / dashboard 不直接轉 / alert routing 換邏輯 / SLO definition 差異）、cost reality check