Observability

Ella Core supports three observability pillars: Metrics, Logs, and Profiles.

Metrics

Ella SMSC exposes Prometheus metrics at GET /api/v1/metrics.

Metric	Type	Description
ellasmsc_build_info	Gauge	Always 1. The version and revision of the running build are in its labels.
ellasmsc_messages_received_total	Counter	Short messages received, one per part, by origin (mobile, api, smpp) and result (accepted, rejected, error). One per submit_sm for smpp.
ellasmsc_messages_completed_total	Counter	Short messages and status reports that reached a final status, by type (message, status_report) and status (delivered, failed, expired, and replaced for a message).
ellasmsc_messages_purged_total	Counter	Short messages deleted once their retention passed, with their status reports and delivery attempts.
ellasmsc_messages_pending	Gauge	Short messages and status reports waiting for delivery, by type and state: due, to be delivered now or being delivered; waiting, for a retry or for the phone to be reachable.
ellasmsc_message_delivery_duration_seconds	Histogram	Time from submission to delivery of the short messages delivered, the time the phone was unreachable included.
ellasmsc_hss_peers	Gauge	Open peers that serve S6c in the operator's realm: HSSs, or agents in front of them. At 0, messages to phones wait.
ellasmsc_peer_requests_total	Counter	Requests to the HSS and to the MMEs, SMSFs and IP-SM-GWs, by interface (s6c, sgd) and result (success, failure, absent_user, error, timeout).
ellasmsc_peer_request_duration_seconds	Histogram	Duration of requests to the HSS and to the MMEs, SMSFs and IP-SM-GWs, by interface.
ellasmsc_smpp_sessions	Gauge	Bound SMPP sessions, by bind type (transmitter, receiver, transceiver).
ellasmsc_smpp_binds_total	Counter	SMPP bind attempts, by result (accepted, rejected).
ellasmsc_smpp_notifications_pending	Gauge	Delivery receipts and SIM answers not yet sent to an ESME and not expired, by type (receipt, sim_answer). A rise means no receiver of the ESME is bound, or it does not acknowledge them.
ellasmsc_smpp_notifications_sent_total	Counter	Delivery receipts and SIM answers that reached a final outcome, by type and result (acknowledged, rejected, expired, no_user_data).
ellasmsc_smpp_submit_duration_seconds	Histogram	Time from a submit_sm read to its submit_sm_resp written.
ellasmsc_database_query_duration_seconds	Histogram	Duration of database calls, the wait for the connection included.
ellasmsc_database_query_errors_total	Counter	Failed database calls.
ellasmsc_database_storage_bytes	Gauge	Size of the database on disk, by file: main, wal.
go_*	Gauge, Counter, Summary	Go runtime: goroutines, heap, garbage-collection pauses.
process_*	Gauge, Counter	Process: memory, CPU, open file descriptors, start time.

Profiles

Ella SMSC exposes the net/http/pprof API at /api/v1/pprof/.

Logs

Ella SMSC writes its logs to standard output, one JSON object per line, at the level of logging.level in the configuration file.

Field	Description
ts	Time of the event.
level	debug, info, warn or error.
msg	What happened.

Other fields depend on the event.

Audit events

Audit events are logs at level info with msg set to audit event.

Field	Description
action	What was done, below.
actor	Email of the user who did it. Empty when unknown.
ip	Address the request came from.
details	What was done, in words.