Faucet can be monitored in a number of ways. Both the faucet and gauge services export instrumentation data via a built-in Prometheus exporter which can be consumed by Prometheus. By default the Prometheus exporter is available on port 9302, this can be changed with env-vars (FAUCET_PROMETHEUS_PORT and FAUCET_PROMETHEUS_ADDR).
Gauge also collects conventional switch statistics (port counters, port state, etc) and can export these to a number of different databases (including Prometheus). For information on configuring gauge see the gauge-configuration section.
Below is a list of the metrics exported by faucet and gauge.