metrics

type M struct {
	Commands       atomic.Int64
	Conflicts      atomic.Int64
	EventsAppended atomic.Int64
	DeadLetters    atomic.Int64
	JobsDispatched atomic.Int64
	CacheHits      atomic.Int64
	Timers         atomic.Int64
	Archived       atomic.Int64
	Deleted        atomic.Int64
	// LatencyNanos accumulates command handling time (decide + append).
	LatencyNanos atomic.Int64
}

type Snapshot struct {
	Commands       int64 `json:"commands"`
	Conflicts      int64 `json:"conflicts"`
	EventsAppended int64 `json:"events_appended"`
	DeadLetters    int64 `json:"dead_letters"`
	JobsDispatched int64 `json:"jobs_dispatched"`
	CacheHits      int64 `json:"cache_hits"`
	Timers         int64 `json:"timers"`
	Archived       int64 `json:"archived"`
	Deleted        int64 `json:"deleted"`
	LatencyNanos   int64 `json:"latency_nanos"`
	// ProjectionLag is the number of events not yet processed by the
	// dispatcher (filled by the engine on request).
	ProjectionLag uint64 `json:"projection_lag"`
	// DispatchStall is the longest time any dispatcher partition with pending
	// events has gone without acknowledging one; DispatchStalls has it per
	// partition. The dispatcher retries transient failures forever, so this
	// is the signal to alert on (e.g. above one minute).
	DispatchStall  time.Duration         `json:"dispatch_stall"`
	DispatchStalls map[int]time.Duration `json:"dispatch_stalls,omitempty"`
}