CA: automatically use BasicSnapshotStore when DRA is enabled

By default CA is built with DeltaSnapshotStore, which isn't integrated
with DRA yet.

cluster-autoscaler/main.go

@@ -37,6 +37,7 @@ import (
 	"k8s.io/autoscaler/cluster-autoscaler/provisioningrequest/besteffortatomic"
 	"k8s.io/autoscaler/cluster-autoscaler/provisioningrequest/checkcapacity"
 	"k8s.io/autoscaler/cluster-autoscaler/provisioningrequest/provreqclient"
+	"k8s.io/autoscaler/cluster-autoscaler/simulator/clustersnapshot"
 	"k8s.io/autoscaler/cluster-autoscaler/simulator/clustersnapshot/predicate"
 	"k8s.io/autoscaler/cluster-autoscaler/simulator/clustersnapshot/store"
 	"k8s.io/autoscaler/cluster-autoscaler/simulator/framework"
@@ -503,10 +504,17 @@ func buildAutoscaler(context ctx.Context, debuggingSnapshotter debuggingsnapshot
 	deleteOptions := options.NewNodeDeleteOptions(autoscalingOptions)
 	drainabilityRules := rules.Default(deleteOptions)
 
+	var snapshotStore clustersnapshot.ClusterSnapshotStore = store.NewDeltaSnapshotStore()
+	if autoscalingOptions.DynamicResourceAllocationEnabled {
+		// TODO(DRA): Remove this once DeltaSnapshotStore is integrated with DRA.
+		klog.Warningf("Using BasicSnapshotStore instead of DeltaSnapshotStore because DRA is enabled. Autoscaling performance/scalability might be decreased.")
+		snapshotStore = store.NewBasicSnapshotStore()
+	}
+
 	opts := core.AutoscalerOptions{
 		AutoscalingOptions:   autoscalingOptions,
 		FrameworkHandle:      fwHandle,
-		ClusterSnapshot:      predicate.NewPredicateSnapshot(store.NewDeltaSnapshotStore(), fwHandle, autoscalingOptions.DynamicResourceAllocationEnabled),
+		ClusterSnapshot:      predicate.NewPredicateSnapshot(snapshotStore, fwHandle, autoscalingOptions.DynamicResourceAllocationEnabled),
 		KubeClient:           kubeClient,
 		InformerFactory:      informerFactory,
 		DebuggingSnapshotter: debuggingSnapshotter,