Struct EngineMetrics 

pub struct EngineMetrics { /* private fields */ }

Process-global engine metrics counters.

Access via EngineMetrics::global(). The global instance is initialised once on first access using OnceLock and lives for the process lifetime.

Counter naming (maps 1:1 to Prometheus metric names)

Method	Prometheus metric	Labels
process_initiated	makod_process_initiated_total	family
process_completed	makod_process_completed_total	family, result
validation_failed	makod_validation_failed_total	message_type, release
outbox_delivery_attempted	makod_outbox_delivery_attempts_total	result
deadline_fired	makod_deadline_fired_total	family
dead_letter_recorded	makod_dead_letter_recorded_total	reason

For makod_dead_letter_recorded_total, the reason label is:

• unknown_pid:<N> when DeadLetterReason::UnknownPid(N) — one label per distinct PID, enabling per-PID alerting
• a short category string (unknown_conversation, version_mismatch, etc.) for all other reason variants

Implementations

impl EngineMetrics

pub fn global() -> &'static Self

Return the process-global EngineMetrics instance.

The instance is initialised lazily on first call. Subsequent calls return the same instance with zero allocation.

pub fn process_initiated(&self, family: &str)

Increment makod_process_initiated_total{family=<family>}.

Call once when a domain workflow receives its first initiating command (e.g. LfAnmeldungCommand::InitiateAnmeldung).

family is the EngineModule::name value ("gpke", "wim", etc.).

pub fn process_completed(&self, family: &str, outcome: ProcessOutcome)

Increment makod_process_completed_total{family=<family>,result=<result>}.

Call once when a workflow transitions to a terminal state (Active, Rejected, timeout, or cancellation).

pub fn validation_failed(&self, message_type: &str, release: &str)

Increment makod_validation_failed_total{message_type=<type>,release=<rel>}.

Call when an inbound message fails validate() or validate_against().

pub fn outbox_delivery_attempted(&self, result: &str)

Increment makod_outbox_delivery_attempts_total{result=<result>}.

Call in the AS4 sender after every delivery attempt. result should be one of "ok", "transport_error", "partner_unknown".

pub fn deadline_fired(&self, family: &str)

Increment makod_deadline_fired_total{family=<family>}.

Call in the deadline scheduler when it dispatches a TimeoutExpired.

pub fn dead_letter_recorded(&self, reason: &str)

Increment makod_dead_letter_recorded_total{reason=<reason>}.

Call in the dead-letter sink when reject() is invoked. reason should match DeadLetterReason’s label string.

pub fn snapshot(&self) -> MetricsSnapshot

Return a snapshot of all counters as a MetricsSnapshot.

This is a read-only operation that does not reset any counters. Counters are monotonically increasing; Prometheus’s rate() handles counter resets on process restart automatically.