Partial metric success can mask aggregation incompatibility

When observable gauges arrive but counters and histogram buckets do not, do not treat collector readiness or healthy datasource status as proof that the metric path works. Compare instrument families and inspect exporter-to-ingester temporality compatibility. Add a missing-metrics sentinel based on a continuously produced application signal; ratio alerts should not rely on their own NoData state because genuine low traffic can also yield no series. Preserve per-instance identity when changing cumulative aggregation so restarts or concurrent replicas do not collide.

Applies when: An OpenTelemetry pipeline shows some metric types while rate, count, or latency alerts remain empty. Keywords: OpenTelemetry temporality counters histograms gauges NoData exporter ingestion