Alerting: add feature flag to control sync timer

packages/grafana-data/src/types/featureToggles.gen.ts

@@ -1246,4 +1246,8 @@ export interface FeatureToggles {
   * Enables profiles exemplars support in profiles drilldown
   */
   profilesExemplars?: boolean;
+  /**
+  * Use synchronized dispatch timer to minimize duplicate notifications across alertmanager HA pods
+  */
+  alertingSyncDispatchTimer?: boolean;
 }

pkg/services/featuremgmt/registry.go

@@ -2060,6 +2060,14 @@ var (
 			Owner:        grafanaObservabilityTracesAndProfilingSquad,
 			FrontendOnly: false,
 		},
+		{
+			Name:            "alertingSyncDispatchTimer",
+			Description:     "Use synchronized dispatch timer to minimize duplicate notifications across alertmanager HA pods",
+			Stage:           FeatureStageExperimental,
+			Owner:           grafanaAlertingSquad,
+			RequiresRestart: true,
+			HideFromDocs:    true,
+		},
 	}
 )
 

pkg/services/featuremgmt/toggles_gen.csv

@@ -279,3 +279,4 @@ multiPropsVariables,experimental,@grafana/dashboards-squad,false,false,true
 smoothingTransformation,experimental,@grafana/datapro,false,false,true
 secretsManagementAppPlatformAwsKeeper,experimental,@grafana/grafana-operator-experience-squad,false,false,false
 profilesExemplars,experimental,@grafana/observability-traces-and-profiling,false,false,false
+alertingSyncDispatchTimer,experimental,@grafana/alerting-squad,false,true,false

pkg/services/featuremgmt/toggles_gen.go

@@ -789,4 +789,8 @@ const (
 	// FlagProfilesExemplars
 	// Enables profiles exemplars support in profiles drilldown
 	FlagProfilesExemplars = "profilesExemplars"
+
+	// FlagAlertingSyncDispatchTimer
+	// Use synchronized dispatch timer to minimize duplicate notifications across alertmanager HA pods
+	FlagAlertingSyncDispatchTimer = "alertingSyncDispatchTimer"
 )

pkg/services/featuremgmt/toggles_gen.json

@@ -511,6 +511,20 @@
         "frontend": true
       }
     },
+    {
+      "metadata": {
+        "name": "alertingSyncDispatchTimer",
+        "resourceVersion": "1768307942819",
+        "creationTimestamp": "2026-01-13T12:39:02Z"
+      },
+      "spec": {
+        "description": "Use synchronized dispatch timer to minimize duplicate notifications across alertmanager HA pods",
+        "stage": "experimental",
+        "codeowner": "@grafana/alerting-squad",
+        "requiresRestart": true,
+        "hideFromDocs": true
+      }
+    },
     {
       "metadata": {
         "name": "alertingTriage",