chore: add loadtest observability setup

server-rs/crates/spacetime-client/src/telemetry.rs

@@ -0,0 +1,75 @@
+use std::time::Duration;
+
+use opentelemetry::{KeyValue, global, metrics::Counter};
+
+use crate::SpacetimeClientError;
+
+// SpacetimeDB procedure 指标只使用 procedure / status_class 等低基数字段，避免把用户或作品 ID 写进指标标签。
+pub(crate) struct ProcedureMetricsGuard {
+    procedure: &'static str,
+    started_at: std::time::Instant,
+}
+
+pub(crate) fn begin_procedure(procedure: &'static str) -> ProcedureMetricsGuard {
+    ProcedureMetricsGuard {
+        procedure,
+        started_at: std::time::Instant::now(),
+    }
+}
+
+impl ProcedureMetricsGuard {
+    pub(crate) fn finish<T>(&self, result: &Result<T, SpacetimeClientError>) {
+        let duration = self.started_at.elapsed();
+        record_procedure(self.procedure, duration, result.is_err());
+    }
+}
+
+struct SpacetimeMetrics {
+    calls: Counter<u64>,
+    errors: Counter<u64>,
+    duration_ms: opentelemetry::metrics::Histogram<f64>,
+}
+
+fn spacetime_metrics() -> &'static SpacetimeMetrics {
+    static METRICS: std::sync::OnceLock<SpacetimeMetrics> = std::sync::OnceLock::new();
+    METRICS.get_or_init(|| {
+        let meter = global::meter("genarrative-spacetime-client");
+        SpacetimeMetrics {
+            calls: meter
+                .u64_counter("genarrative.spacetime.procedure.calls")
+                .with_description("SpacetimeDB procedure call count")
+                .build(),
+            errors: meter
+                .u64_counter("genarrative.spacetime.procedure.errors")
+                .with_description("SpacetimeDB procedure error count")
+                .build(),
+            duration_ms: meter
+                .f64_histogram("genarrative.spacetime.procedure.duration_ms")
+                .with_unit("ms")
+                .with_description("SpacetimeDB procedure duration in milliseconds")
+                .build(),
+        }
+    })
+}
+
+fn record_procedure(
+    procedure: &'static str,
+    duration: Duration,
+    failed: bool,
+) {
+    let labels = vec![
+        KeyValue::new("procedure", procedure),
+        KeyValue::new(
+            "status_class",
+            if failed { "error" } else { "ok" },
+        ),
+    ];
+    let metrics = spacetime_metrics();
+    metrics.calls.add(1, &labels);
+    metrics
+        .duration_ms
+        .record(duration.as_secs_f64() * 1000.0, &labels);
+    if failed {
+        metrics.errors.add(1, &labels);
+    }
+}