Method observe

nodedb-cluster/src/loop_metrics.rs:82–86

Record a completed tick. Increments `iterations_total` and stores the duration for the `last_iteration_duration_seconds` gauge. Call regardless of success/failure — errors are tracked separately via [`record_error`](Self::record_error).

(&self, duration: Duration)

    /// gauge. Call regardless of success/failure — errors are tracked
    /// separately via [`record_error`](Self::record_error).
    pub fn observe(&self, duration: Duration) {
        let ns = u64::try_from(duration.as_nanos()).unwrap_or(u64::MAX);
        self.last_iteration_duration_ns.store(ns, Ordering::Relaxed);
        self.iterations_total.fetch_add(1, Ordering::Relaxed);
    }

    /// Increment the counter for an error kind. `kind` must be a short
    /// bounded label — never a formatted error string.