do not allocate gauge if cardinality metrics are turned off

uber-go · Feb 14, 2024 · f8dac6f · f8dac6f
1 parent 83f9861
commit f8dac6f
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Showing 2 changed files with 20 additions and 1 deletion.
diff --git a/scope_registry.go b/scope_registry.go
@@ -103,7 +103,7 @@ func newScopeRegistryWithShardCount(
 		}
 		r.subscopes[i].s[scopeRegistryKey(root.prefix, root.tags)] = root
 	}
-	if r.root.cachedReporter != nil {
+	if r.root.cachedReporter != nil && !omitCardinalityMetrics {
 		r.cachedCounterCardinalityGauge = r.root.cachedReporter.AllocateGauge(r.sanitizedCounterCardinalityName, r.cardinalityMetricsTags)
 		r.cachedGaugeCardinalityGauge = r.root.cachedReporter.AllocateGauge(r.sanitizedGaugeCardinalityName, r.cardinalityMetricsTags)
 		r.cachedHistogramCardinalityGauge = r.root.cachedReporter.AllocateGauge(r.sanitizedHistogramCardinalityName, r.cardinalityMetricsTags)

diff --git a/scope_registry_test.go b/scope_registry_test.go
@@ -221,3 +221,22 @@ func TestForEachScopeConcurrent(t *testing.T) {
 
 	<-done
 }
+
+func TestCachedReporterNoAllocOnOmitInternalMetrics(t *testing.T) {
+	r := newTestStatsReporter()
+	root, closer := NewRootScope(ScopeOptions{CachedReporter: r, OmitCardinalityMetrics: true}, 0)
+	wantGauges := 1
+
+	s := root.(*scope)
+
+	r.gg.Add(wantGauges)
+	s.Gauge("gauge-foo").Update(3)
+
+	closer.Close()
+	r.WaitAll()
+
+	assert.Equal(
+		t, wantGauges, len(r.gauges), "expected %d gauges, got %d gauges", wantGauges,
+		len(r.gauges),
+	)
+}