Metrics

Every network function that exposes Prometheus metrics, the endpoint it serves them on, and the representative series you'll scrape.

dflux TinyCore network functions export Prometheus metrics over a plain-text /metrics endpoint. Point any Prometheus-compatible scraper at the addresses below. The metric names listed here match the series each NF exports; each NF also exports the standard Go runtime and process collectors.

Endpoints

NF	Endpoint	Notes
NRF	`:8080/metrics`	Served on the same listener as the SBI.
DMF	`:8081/metrics`	Served on the same listener as the SBI.
DPF	`:8082/metrics`	Served on the same listener as the SBI.
SMSF	`:8083/metrics`	Served on the same listener as the SBI (optional NF).
NSSF	`:8084/metrics`	Served on the same listener as the SBI (optional NF).
UPF	`:9095/metrics`	Dedicated metrics listener (`-metrics-addr`), separate from N4.

Health endpoints stay open

/health, /ready, and /metrics are never gated by OAuth2. Observe structured logs with -json / -debug alongside the series below.

NRF metrics

Representative series exported by the NRF:

Metric	Type	Meaning
`nrf_nf_instances_registered`	Gauge	Currently registered NF instances, labeled by `nf_type`.
`nrf_nf_registrations_total`	Counter	NF registration events, by `nf_type`.
`nrf_nf_deregistrations_total`	Counter	NF deregistration events, by `nf_type` and `reason`.
`nrf_heartbeat_expirations_total`	Counter	Heartbeat-expiry state transitions, by `transition`.
`nrf_discovery_requests_total`	Counter	NF discovery searches, by `target_nf_type` and `requester_nf_type`.
`nrf_discovery_results_total`	Counter	NF profiles returned by discovery, by `target_nf_type`.
`nrf_active_subscriptions`	Gauge	Active NF status-change subscriptions.
`nrf_token_requests_total`	Counter	OAuth2 access-token requests, by `status`.
`nrf_http_requests_total`	Counter	HTTP requests, by `method`, `path`, `status`.
`nrf_http_request_duration_seconds`	Histogram	HTTP request latency, by `method` and `path`.

The NRF also exports notification, subscription-expiry, and store-operation series (nrf_notifications_sent_total, nrf_subscription_expirations_total, nrf_store_operation_duration_seconds, and others).

Grafana dashboard

A ready-made NRF overview dashboard ships at nrf/dashboards/nrf-overview.json — import it into Grafana to chart the series above.

DMF metrics

Representative series exported by the DMF on its SBI port:

Metric	Type	Meaning
`dmf_registrations_total`	Counter	UE registration procedures, by `type` and `result`.
`dmf_authentications_total`	Counter	Primary authentication outcomes, by `result`.
`dmf_pdu_sessions_total`	Counter	PDU session events, by `event` and `result`.
`dmf_ngap_messages_total`	Counter	NGAP messages, by `procedure` and `direction`.
`dmf_n2_load_percent`	Gauge	N2 offered load as a percentage of `-ngap-overload-n2-budget` (NaN if no budget is set).

The DMF also exports NAS-security, PFCP-reliability, usage-record, and rehydrate series ( dmf_nas_security_failures_total, dmf_smf_pfcp_events_total, dmf_ue_rehydrate_total, and others).

UPF metrics

Metric	Type	Meaning
`upf_pfcp_messages_total`	Counter	PFCP messages, by `type` and `direction` (rx\|tx).
`upf_pfcp_errors_total`	Counter	PFCP processing errors, by `kind`.
`upf_sessions_active`	Gauge	PFCP sessions currently installed in the datapath.
`upf_associations_active`	Gauge	Active PFCP node associations.
`upf_datapath_packets_total`	Counter	Forwarded packets, by `direction` (ul\|dl) and `family` (v4\|v6\|unknown). Userspace datapath only.
`upf_datapath_bytes_total`	Counter	Forwarded inner-payload bytes, same labels as above. Userspace datapath only.

Datapath series need the userspace datapath

The upf_datapath_* counters are emitted by the userspace forwarder. With the default stub datapath the UPF still serves /metrics and the PFCP/session series, but no packets are forwarded so the datapath counters stay at zero.

DPF metrics

Metric	Type	Meaning
`dpf_http_requests_total`	Counter	HTTP requests, by `method`, `path`, and `status`.
`dpf_http_request_duration_seconds`	Histogram	HTTP request latency, by `method` and `path`.

The DPF currently exports HTTP-level metrics for its AUSF, UDM, UDR, and PCF endpoints; the path label distinguishes which service handled the request.

NSSF and SMSF metrics

Optional NFs also serve /metrics on their SBI ports. Representative series:

NSSF — nssf_selections_total (slice selections by mode and result).
SMSF — smsf_messages_total (by direction and result), smsf_active_sm_contexts, smsf_delivery_attempts_total.

For a worked example of scraping these endpoints and wiring up Prometheus and Grafana, see Observability.