ADR 0002: Query Tempo/Loki/Mimir directly, no own storage

Status: accepted (2026-07-03)

Context

cboxdk/laravel-telemetry recommends an OTLP + Prometheus stack (Tempo, Loki, Prometheus/Mimir). Nightwatch-style products instead ingest into their own storage, which means agents, duplication and retention policy owned by the tool.

Decision

This package stores nothing. It is a stateless query layer speaking PromQL, TraceQL and LogQL against the backends the apps already export to, through three narrow contracts (MetricsSource, TracesSource, LogsSource) with lazy, named, multi-tenant-aware connections.

Consequences

• Zero ingestion infrastructure; retention/cost stay in the Grafana stack.
• The UI works for every service exporting to the same backends, not just the app it is installed in — fleet view for free.
• Latency of every screen is bounded by backend query speed; a short-TTL cache layer (Laravel cache) is the planned mitigation, not a database.
• Features requiring state (issue assignment, resolve/ignore, thresholds) will need explicit, minimal app-side tables when they arrive — deferred until those features exist.