Alerting: Add ability to control scheduler tick interval via config (#71980)

* add ability to control scheduler interval via config
* add feature flag `configurableSchedulerTick`

pkg/services/featuremgmt/registry.go

@@ -681,5 +681,14 @@ var (
 			Stage:       FeatureStageExperimental,
 			Owner:       grafanaObservabilityMetricsSquad,
 		},
+		{
+			Name:            "configurableSchedulerTick",
+			Description:     "Enable changing the scheduler base interval via configuration option unified_alerting.scheduler_tick_interval",
+			Stage:           FeatureStageExperimental,
+			FrontendOnly:    false,
+			Owner:           grafanaAlertingSquad,
+			RequiresRestart: true,
+			HideFromDocs:    true,
+		},
 	}
 )

pkg/services/featuremgmt/toggles_gen.csv

@@ -98,3 +98,4 @@ awsAsyncQueryCaching,experimental,@grafana/aws-datasources,false,false,false,fal
 splitScopes,preview,@grafana/grafana-authnz-team,false,false,true,false
 azureMonitorDataplane,GA,@grafana/partner-datasources,false,false,false,false
 prometheusConfigOverhaulAuth,experimental,@grafana/observability-metrics,false,false,false,false
+configurableSchedulerTick,experimental,@grafana/alerting-squad,false,false,true,false

pkg/services/featuremgmt/toggles_gen.go

@@ -402,4 +402,8 @@ const (
 	// FlagPrometheusConfigOverhaulAuth
 	// Update the Prometheus configuration page with the new auth component
 	FlagPrometheusConfigOverhaulAuth = "prometheusConfigOverhaulAuth"
+
+	// FlagConfigurableSchedulerTick
+	// Enable changing the scheduler base interval via configuration option unified_alerting.scheduler_tick_interval
+	FlagConfigurableSchedulerTick = "configurableSchedulerTick"
 )

pkg/services/ngalert/schedule/schedule.go

@@ -130,6 +130,7 @@ func NewScheduler(cfg SchedulerCfg, stateManager *state.Manager) *schedule {
 }
 
 func (sch *schedule) Run(ctx context.Context) error {
+	sch.log.Info("Starting scheduler", "tickInterval", sch.baseInterval)
 	t := ticker.New(sch.clock, sch.baseInterval, sch.metrics.Ticker)
 	defer t.Stop()