use alpha stage feature-gate

Author: Frapschen

.chloggen/fix-42462.yaml

@@ -16,8 +16,8 @@ issues: [42462]
 # These lines will be padded with 2 spaces and then inserted directly into the document.
 # Use pipe (|) for multiline entries.
 subtext: |
-  This change introduces a breaking change, which is now guarded by the feature gate `connector.spanmetrics.legacyDefaultMetricsUnit`.
-  Currently, the feature gate is enabled by default, so the unit will remain `ms`. After one or two release cycles, the unit will switch to `s` and the feature gate will also be disabled by default.
+  This change introduces a breaking change, which is now guarded by the feature gate `connector.spanmetrics.useSCDefaultMetricsUnit`.
+  Currently, the feature gate is disabled by default, so the unit will remain `ms`. After one release cycle, the unit will switch to `s` and the feature gate will also be enabled by default.
   To revert this change manually, users can either enable the feature gate or modify the configuration as follows:
   ```
   connectors

connector/spanmetricsconnector/README.md

@@ -23,6 +23,18 @@
 [Stability Level]: https://github.com/open-telemetry/opentelemetry-collector/blob/main/docs/component-stability.md#stability-levels
 <!-- end autogenerated section -->
 
+⚠️ Breaking Change Warning: 
+The default duration metrics unit will change from `ms` to `s` to adhere to the OpenTelemetry semantic conventions and a feature gate `connector.spanmetrics.useSCDefaultMetricsUnit` is also added.
+
+Currently, the feature gate is disabled by default, so the unit will remain `ms`. After one release cycle, the unit will switch to `s` and the feature gate will also be enabled by default.
+To revert this change manually, users can either disabled the feature gate or modify the configuration as follows:
+  ```
+  connectors
+    spanmetrics:
+      histogram:
+        unit: "ms"
+  ```
+
 ## Overview
 
 Aggregates Request, Error and Duration (R.E.D) OpenTelemetry metrics from span data.
@@ -96,7 +108,7 @@ The following settings can be optionally configured:
 - `histogram` (default: `explicit`): Use to configure the type of histogram to record
   calculated from spans duration measurements. Must be either `explicit` or `exponential`.
   - `disable` (default: `false`): Disable all histogram metrics.
-  - `unit` (default: `ms`, it will change to `s` in the next release, you can enable feature-gate `connector.spanmetrics.legacyDefaultMetricsUnit` to keep use `ms` unit): The time unit for recording duration measurements.
+  - `unit` (default: `ms`): The time unit for recording duration measurements.
   calculated from spans duration measurements. One of either: `ms` or `s`.
   - `dimensions`: additional attributes to add as dimensions to the `traces.span.metrics.duration` metric, 
   which will be included _on top of_ the common and configured `dimensions` for span attributes and resource attributes.

connector/spanmetricsconnector/config_test.go

@@ -26,9 +26,7 @@ import (
 func TestLoadConfig(t *testing.T) {
 	t.Parallel()
 
-	// disable legacyDefaultMetricsUnit featuregate
-	require.NoError(t, featuregate.GlobalRegistry().Set(legacyDefaultMetricsUnit.ID(), false))
-
+	require.NoError(t, featuregate.GlobalRegistry().Set(useSCDefaultMetricsUnit.ID(), true))
 	cm, err := confmaptest.LoadConf(filepath.Join("testdata", "config.yaml"))
 	require.NoError(t, err)
 

connector/spanmetricsconnector/factory.go

@@ -25,13 +25,13 @@ const (
 	DefaultNamespace                        = "traces.span.metrics"
 	legacyMetricNamesFeatureGateID          = "connector.spanmetrics.legacyMetricNames"
 	includeCollectorInstanceIDFeatureGateID = "connector.spanmetrics.includeCollectorInstanceID"
-	legacyDefaultMetricsUnitFeatureGateID   = "connector.spanmetrics.legacyDefaultMetricsUnit"
+	useSCDefaultMetricsUnitFeatureGateID    = "connector.spanmetrics.useSCDefaultMetricsUnit"
 )
 
 var (
 	legacyMetricNamesFeatureGate *featuregate.Gate
 	includeCollectorInstanceID   *featuregate.Gate
-	legacyDefaultMetricsUnit     *featuregate.Gate
+	useSCDefaultMetricsUnit      *featuregate.Gate
 )
 
 func init() {
@@ -48,10 +48,10 @@ func init() {
 		featuregate.WithRegisterDescription("When enabled, connector add collector.instance.id to default dimensions."),
 		featuregate.WithRegisterReferenceURL("https://github.com/open-telemetry/opentelemetry-collector-contrib/issues/40400"),
 	)
-	legacyDefaultMetricsUnit = featuregate.GlobalRegistry().MustRegister(
-		legacyDefaultMetricsUnitFeatureGateID,
-		featuregate.StageBeta, // current enabled by default and disable it in the next release
-		featuregate.WithRegisterDescription("enabled by default, connector use ms unit for duration metrics."),
+	useSCDefaultMetricsUnit = featuregate.GlobalRegistry().MustRegister(
+		useSCDefaultMetricsUnitFeatureGateID,
+		featuregate.StageAlpha,
+		featuregate.WithRegisterDescription("When enabled, connector use second as default unit for duration metrics."),
 		featuregate.WithRegisterReferenceURL("https://github.com/open-telemetry/opentelemetry-collector-contrib/issues/42103"),
 	)
 }
@@ -71,11 +71,11 @@ func createDefaultConfig() component.Config {
 		ResourceMetricsCacheSize: defaultResourceMetricsCacheSize,
 		MetricsFlushInterval:     60 * time.Second,
 		Histogram: HistogramConfig{Disable: false, Unit: func() metrics.Unit {
-			if legacyDefaultMetricsUnit.IsEnabled() {
-				return metrics.Milliseconds
+			if useSCDefaultMetricsUnit.IsEnabled() {
+				return metrics.Seconds
 			}
 
-			return metrics.Seconds
+			return metrics.Milliseconds
 		}()},
 		Namespace:                   DefaultNamespace,
 		AggregationCardinalityLimit: 0,