Module telemetry 

Observability layer — OpenTelemetry tracing, structured logging, Prometheus metrics.

All components are feature-gated for zero overhead when disabled:

• tracing-subscriber: console logging — installs a fmt/EnvFilter subscriber via TelemetryConfig::init (the tracing facade itself is always available)
• metrics: Prometheus metric definitions and export
• otel-otlp: OTLP trace and metric export to any OTel collector
• otel-gcp: Google Cloud-native trace and metric export (Cloud Trace + Cloud Monitoring)

Re-exports

pub use metrics_exporter_prometheus as metrics_exporter;

Modules

logging

Structured logging helpers.

metrics

Prometheus metric definitions — counters, histograms, gauges.

spans

OpenTelemetry span definitions for session operations.

Structs

Exporters

The exporters a TelemetryConfig asks for, built but not yet attached to a subscriber: for an application that builds its own subscriber (to add layers of its own) and attaches Exporters::layer to it when the otel-base feature is enabled.

TelemetryConfig

Telemetry configuration.

TelemetryGuard

Guard that keeps telemetry systems alive while held. Drop this to flush and shutdown OTel exporters.