Module observability 

Pipeline-internal observability: tracing spans and metrics counters/ histograms wired automatically around every source, sink, transform, and state-store operation. See docs/superpowers/specs/2026-05-23-observability-otel-prometheus-design.md.

Modules

otel

OpenTelemetry (OTLP) export of traces + metrics (#201).

resilience

Metric registration + emit helpers for the unified resilience policy (retry/backoff, circuit breaker, poison-pill). See docs/superpowers/specs/2026-06-17-resilience-policy-design.md (§Metrics).

Structs

DurationGuard

On Drop, records the elapsed time since construction into the named histogram with the supplied labels. Recording on drop guarantees a sample even if the surrounding future is cancelled or panics.

InstallReport

Report from install_observability so callers can log what actually happened (recorder installed vs. already-installed vs. disabled).

InstrumentedSink

Wraps a &dyn Sink (or any &S: Sink) and emits spans + metrics around write_batch and flush. Constructed by Pipeline::run.

InstrumentedSource

Wraps a &dyn Source (or any &S: Source) and emits spans + metrics around every call. Constructed by Pipeline::run and never exposed to end users; the wrapped source remains the user-facing object.

InstrumentedStateStore

Wraps an Arc<dyn StateStore> and emits faucet.state.* spans + metrics around every operation.

Labels

Common labels carried by every span and metric.

ObservabilityConfig

Configuration for install_observability. Either or both sections may be None; unset sections install nothing.

PrometheusConfig

RunStreamOptions

TracingConfig

Enums

InstallError

Functions

install_observabilityNon-observability-install

Non-observability-install stub. Returns an empty report, never panics.

instrumented_apply_contract

Apply the contract pass and emit metrics. Returns the same outcome as apply_contract; on a fail-policy breach, increments faucet_contract_aborts_total before propagating the error.

instrumented_apply_masking

Apply the masking pass and emit metrics. Infallible — masking rewrites matching fields in place and never fails a run. Increments faucet_masking_fields_total{pipeline,row,rule,action,detector} once per masked field (detector is "" for name-based matches).

instrumented_apply_quality

Apply the quality pass and emit metrics. Returns the same outcome as apply_quality; on abort, increments faucet_quality_aborts_total before propagating the error.

instrumented_apply_stages

Apply a sequence of compiled stages to records (a full page). Per-record stages flat-map over each record; PageFn stages transform the whole page at once. Emits one faucet.transform.apply span and counters faucet_transform_records_in_total / _records_out_total per call (per page).

register_build_info

Register the faucet_build_info{version} gauge (set to 1) under the currently-installed metrics recorder. Safe to call from any code path that wants to ensure the gauge is set; install_observability invokes this automatically. Gauges are naturally idempotent under the metrics model — repeat calls just re-set the same value.

schema_drift

Emit faucet_schema_drift_total{pipeline,row,connector,mode,kind} for a detected drift: count columns of kind handled under policy mode. No-op when count == 0.

strip_type_name

Strip a Rust type_name string to its final path segment.

update_bookmark_lag

Update the bookmark-lag gauges if the bookmark is a parseable RFC3339 timestamp. Returns true if the gauges were updated, false otherwise.