Every op is instrumented — for free.
Every source, sink, transform, and state operation emits Prometheus metrics and OpenTelemetry tracing spans automatically — no per-connector code, no wrappers. Scrape it, ship spans over OTLP, and point Grafana at it.
Counters, gauges, and histograms across the whole path.
Over 120 metrics across the runtime — a representative set per subsystem below; the full list, histogram buckets, and label values are in the reference.
Source
faucet_source_records_total counter Records read faucet_source_errors_total counter Read errors, by kind faucet_source_page_duration_seconds histogram Time per page faucet_source_in_flight gauge Pages being read Sink
faucet_sink_records_total counter Records written faucet_sink_writes_total counter Write calls faucet_sink_errors_total counter Write errors faucet_sink_write_duration_seconds histogram Time per write faucet_sink_flush_duration_seconds histogram Time per flush Transform
faucet_transform_records_in_total counter Records in faucet_transform_records_out_total counter Records out faucet_transform_duration_seconds histogram Time per page faucet_transform_errors_total counter Errors, by kind State
faucet_state_get_total counter Bookmark reads (hit/miss) faucet_state_put_total counter Bookmark writes faucet_state_errors_total counter State errors, by op faucet_state_*_duration_seconds histogram Time per op Pipeline
faucet_pipeline_runs_total counter Runs, by status faucet_pipeline_run_duration_seconds histogram Run wall-clock faucet_pipeline_in_flight gauge Runs in progress faucet_pipeline_seconds_since_last_bookmark gauge Freshness faucet_build_info gauge Version label (group_left) Dead-letter queue
faucet_sink_dlq_records_total counter Rows routed to the DLQ faucet_sink_dlq_pages_total counter DLQ pages written faucet_sink_dlq_write_duration_seconds histogram Time per DLQ write faucet_sink_dlq_budget_exceeded_total counter DLQ budget exceeded Governance
faucet_quality_checks_total counter Quality checks run faucet_contract_violations_total counter Contract breaches faucet_schema_drift_total counter Drift events, by kind faucet_masking_fields_total counter Fields masked faucet_lineage_events_total counter OpenLineage events emitted faucet_pipeline_sla_violations_total counter SLA violations, by kind Resilience
faucet_resilience_retries_total counter Retries, by connector faucet_resilience_circuit_state gauge Circuit-breaker state faucet_resilience_giveup_total counter Give-ups after retries faucet_resilience_poison_rows_total counter Poison rows quarantined Topology & scale
faucet_tee_records_total counter Records fanned out (tee) faucet_merge_records_total counter Records merged (fan-in) faucet_join_matches_total counter Join matches faucet_pipeline_adaptive_batch_size gauge Adaptive batch size Plus metrics for backfill, scheduling, serve/cluster, notifications, and cleanup — see all 120+ in the reference →
Scrape it in two minutes.
faucet serve exposes a Prometheus /metrics endpoint;
point your scraper at it. Tracing spans export over OTLP to any collector.
faucet_build_info carries the running version — group_left
it onto any metric to annotate dashboards.
- Common labels:
pipeline,row,connector. run_idis a span attribute only — never a high-cardinality label.- Drop-guard timers sample even on cancellation; panics surface as a typed error kind.
# expose /metrics
faucet serve --metrics-addr 0.0.0.0:9090
# prometheus.yml
scrape_configs:
- job_name: faucet
static_configs:
- targets: ["localhost:9090"]
# annotate any panel with the running version
rate(faucet_sink_records_total[5m])
* on() group_left(version) faucet_build_infoYour first pipeline runs in five minutes.
Install the CLI, scaffold a config, and move real data — nothing external to stand up.
curl -LsSf https://github.com/faucet-hq/faucet-stream/releases/latest/download/faucet-cli-installer.sh | sh brew install faucet-hq/faucet-stream/faucet-cli