Cherry pick expander changes

cluster-autoscaler/FAQ.md

@@ -882,6 +882,7 @@ The following startup parameters are supported for cluster autoscaler:
 | `balance-similar-node-groups` | Detect similar node groups and balance the number of nodes between them | false
 | `balancing-ignore-label` | Define a node label that should be ignored when considering node group similarity. One label per flag occurrence. | ""
 | `balancing-label` | Define a node label to use when comparing node group similarity. If set, all other comparison logic is disabled, and only labels are considered when comparing groups. One label per flag occurrence. | ""
+| `skip-similar-node-group-recomputation` | Should CA skip similar NodeGroup recomputation for the best option returned by the expander during scaleups. You must enable `balance-similar-node-groups` for this to work. | false
 | `node-autoprovisioning-enabled` | Should CA autoprovision node groups when needed | false
 | `max-autoprovisioned-node-group-count` | The maximum number of autoprovisioned groups in the cluster | 15
 | `unremovable-node-recheck-timeout` | The timeout before we check again a node that couldn't be removed before | 5 minutes

cluster-autoscaler/config/autoscaling_options.go

@@ -120,6 +120,8 @@ type AutoscalingOptions struct {
 	GpuTotal []GpuLimits
 	// NodeGroupAutoDiscovery represents one or more definition(s) of node group auto-discovery
 	NodeGroupAutoDiscovery []string
+	// SkipSimilarNodeGroupRecomputation skips similar NodeGroup recomputation for the best option returned by the expander during scaleups
+	SkipSimilarNodeGroupRecomputation bool
 	// EstimatorName is the estimator used to estimate the number of needed nodes in scale up.
 	EstimatorName string
 	// ExpanderNames sets the chain of node group expanders to be used in scale up

cluster-autoscaler/core/scaleup/orchestrator/orchestrator.go

@@ -229,7 +229,7 @@ func (o *ScaleUpOrchestrator) ScaleUp(
 		}
 	}
 
-	scaleUpInfos, aErr := o.balanceScaleUps(now, bestOption.NodeGroup, newNodes, nodeInfos, schedulablePodGroups)
+	scaleUpInfos, aErr := o.balanceScaleUps(now, bestOption, newNodes, nodeInfos, schedulablePodGroups)
 	if aErr != nil {
 		return status.UpdateScaleUpError(
 			&status.ScaleUpStatus{CreateNodeGroupResults: createNodeGroupResults, PodsTriggeredScaleUp: bestOption.Pods},
@@ -680,13 +680,16 @@ func (o *ScaleUpOrchestrator) GetCappedNewNodeCount(newNodeCount, currentNodeCou
 
 func (o *ScaleUpOrchestrator) balanceScaleUps(
 	now time.Time,
-	nodeGroup cloudprovider.NodeGroup,
+	bestOption *expander.Option,
 	newNodes int,
 	nodeInfos map[string]*schedulerframework.NodeInfo,
 	schedulablePodGroups map[string][]estimator.PodEquivalenceGroup,
 ) ([]nodegroupset.ScaleUpInfo, errors.AutoscalerError) {
-	// Recompute similar node groups in case they need to be updated
-	similarNodeGroups := o.ComputeSimilarNodeGroups(nodeGroup, nodeInfos, schedulablePodGroups, now)
+	similarNodeGroups := bestOption.SimilarNodeGroups
+	if !o.autoscalingContext.SkipSimilarNodeGroupRecomputation {
+		// Recompute similar node groups in case they need to be updated
+		similarNodeGroups = o.ComputeSimilarNodeGroups(bestOption.NodeGroup, nodeInfos, schedulablePodGroups, now)
+	}
 	if similarNodeGroups != nil {
 		// if similar node groups are found, log about them
 		similarNodeGroupIds := make([]string, 0)
@@ -699,7 +702,7 @@ func (o *ScaleUpOrchestrator) balanceScaleUps(
 		klog.V(2).Info("No similar node groups found")
 	}
 
-	targetNodeGroups := []cloudprovider.NodeGroup{nodeGroup}
+	targetNodeGroups := []cloudprovider.NodeGroup{bestOption.NodeGroup}
 	for _, ng := range similarNodeGroups {
 		targetNodeGroups = append(targetNodeGroups, ng)
 	}

cluster-autoscaler/expander/grpcplugin/grpc_client.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	v1 "k8s.io/api/core/v1"
+	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider"
 	"k8s.io/autoscaler/cluster-autoscaler/expander"
 	"k8s.io/autoscaler/cluster-autoscaler/expander/grpcplugin/protos"
 	"k8s.io/klog/v2"
@@ -111,11 +112,20 @@ func populateOptionsForGRPC(expansionOptions []expander.Option) ([]*protos.Optio
 	nodeGroupIDOptionMap := make(map[string]expander.Option)
 	for _, option := range expansionOptions {
 		nodeGroupIDOptionMap[option.NodeGroup.Id()] = option
-		grpcOptionsSlice = append(grpcOptionsSlice, newOptionMessage(option.NodeGroup.Id(), int32(option.NodeCount), option.Debug, option.Pods))
+		similarNodeGroupIds := getSimilarNodeGroupIds(option)
+		grpcOptionsSlice = append(grpcOptionsSlice, newOptionMessage(option.NodeGroup.Id(), int32(option.NodeCount), option.Debug, option.Pods, similarNodeGroupIds))
 	}
 	return grpcOptionsSlice, nodeGroupIDOptionMap
 }
 
+func getSimilarNodeGroupIds(option expander.Option) []string {
+	var similarNodeGroupIds []string
+	for _, sng := range option.SimilarNodeGroups {
+		similarNodeGroupIds = append(similarNodeGroupIds, sng.Id())
+	}
+	return similarNodeGroupIds
+}
+
 // populateNodeInfoForGRPC looks at the corresponding v1.Node object per NodeInfo object, and populates the grpcNodeInfoMap with these to pass over grpc
 func populateNodeInfoForGRPC(nodeInfos map[string]*schedulerframework.NodeInfo) map[string]*v1.Node {
 	grpcNodeInfoMap := make(map[string]*v1.Node)
@@ -132,8 +142,9 @@ func transformAndSanitizeOptionsFromGRPC(bestOptionsResponseOptions []*protos.Op
 			klog.Error("GRPC server returned nil Option")
 			continue
 		}
-		if _, ok := nodeGroupIDOptionMap[option.NodeGroupId]; ok {
-			options = append(options, nodeGroupIDOptionMap[option.NodeGroupId])
+		if expanderOption, ok := nodeGroupIDOptionMap[option.NodeGroupId]; ok {
+			expanderOption.SimilarNodeGroups = getRetainedSimilarNodegroups(option, expanderOption)
+			options = append(options, expanderOption)
 		} else {
 			klog.Errorf("GRPC server returned invalid nodeGroup ID: %s", option.NodeGroupId)
 			continue
@@ -142,6 +153,25 @@ func transformAndSanitizeOptionsFromGRPC(bestOptionsResponseOptions []*protos.Op
 	return options
 }
 
-func newOptionMessage(nodeGroupId string, nodeCount int32, debug string, pods []*v1.Pod) *protos.Option {
-	return &protos.Option{NodeGroupId: nodeGroupId, NodeCount: nodeCount, Debug: debug, Pod: pods}
+// Any similar options that were not included in the original grpcExpander request, but were added
+// as part of the response, will be ignored
+func getRetainedSimilarNodegroups(grpcOption *protos.Option, expanderOption expander.Option) []cloudprovider.NodeGroup {
+	var retainedSimilarNodeGroups []cloudprovider.NodeGroup
+	for _, sng := range expanderOption.SimilarNodeGroups {
+		retained := false
+		for _, id := range grpcOption.SimilarNodeGroupIds {
+			if sng.Id() == id {
+				retained = true
+				continue
+			}
+		}
+		if retained {
+			retainedSimilarNodeGroups = append(retainedSimilarNodeGroups, sng)
+		}
+	}
+	return retainedSimilarNodeGroups
+}
+
+func newOptionMessage(nodeGroupId string, nodeCount int32, debug string, pods []*v1.Pod, similarNodeGroupIds []string) *protos.Option {
+	return &protos.Option{NodeGroupId: nodeGroupId, NodeCount: nodeCount, Debug: debug, Pod: pods, SimilarNodeGroupIds: similarNodeGroupIds}
 }

cluster-autoscaler/expander/grpcplugin/grpc_client_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/assert"
 	v1 "k8s.io/api/core/v1"
+	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider"
 	"k8s.io/autoscaler/cluster-autoscaler/expander/grpcplugin/protos"
 	"k8s.io/autoscaler/cluster-autoscaler/expander/mocks"
 	. "k8s.io/autoscaler/cluster-autoscaler/utils/test"
@@ -58,6 +59,11 @@ var (
 		Debug:     "m4.4xlarge",
 		NodeGroup: test.NewTestNodeGroup("my-asg.m4.4xlarge", 10, 1, 1, true, false, "m4.4xlarge", nil, nil),
 	}
+	eoT2MicroWithSimilar = expander.Option{
+		Debug:             "t2.micro",
+		NodeGroup:         test.NewTestNodeGroup("my-asg.t2.micro", 10, 1, 1, true, false, "t2.micro", nil, nil),
+		SimilarNodeGroups: []cloudprovider.NodeGroup{test.NewTestNodeGroup("my-similar-asg.t2.micro", 10, 1, 1, true, false, "t2.micro", nil, nil)},
+	}
 	options = []expander.Option{eoT2Micro, eoT2Large, eoT3Large, eoM44XLarge}
 
 	grpcEoT2Micro = protos.Option{
@@ -84,6 +90,20 @@ var (
 		Debug:       eoM44XLarge.Debug,
 		Pod:         eoM44XLarge.Pods,
 	}
+	grpcEoT2MicroWithSimilar = protos.Option{
+		NodeGroupId:         eoT2Micro.NodeGroup.Id(),
+		NodeCount:           int32(eoT2Micro.NodeCount),
+		Debug:               eoT2Micro.Debug,
+		Pod:                 eoT2Micro.Pods,
+		SimilarNodeGroupIds: []string{eoT2MicroWithSimilar.SimilarNodeGroups[0].Id()},
+	}
+	grpcEoT2MicroWithSimilarWithExtraOptions = protos.Option{
+		NodeGroupId:         eoT2Micro.NodeGroup.Id(),
+		NodeCount:           int32(eoT2Micro.NodeCount),
+		Debug:               eoT2Micro.Debug,
+		Pod:                 eoT2Micro.Pods,
+		SimilarNodeGroupIds: []string{eoT2MicroWithSimilar.SimilarNodeGroups[0].Id(), "extra-ng-id"},
+	}
 )
 
 func TestPopulateOptionsForGrpc(t *testing.T) {
@@ -116,6 +136,12 @@ func TestPopulateOptionsForGrpc(t *testing.T) {
 				eoM44XLarge.NodeGroup.Id(): eoM44XLarge,
 			},
 		},
+		{
+			desc:         "similar nodegroups are included",
+			opts:         []expander.Option{eoT2MicroWithSimilar},
+			expectedOpts: []*protos.Option{&grpcEoT2MicroWithSimilar},
+			expectedMap:  map[string]expander.Option{eoT2MicroWithSimilar.NodeGroup.Id(): eoT2MicroWithSimilar},
+		},
 	}
 	for _, tc := range testCases {
 		grpcOptionsSlice, nodeGroupIDOptionMap := populateOptionsForGRPC(tc.opts)
@@ -146,18 +172,44 @@ func TestPopulateNodeInfoForGRPC(t *testing.T) {
 }
 
 func TestValidTransformAndSanitizeOptionsFromGRPC(t *testing.T) {
-	responseOptionsSlice := []*protos.Option{&grpcEoT2Micro, &grpcEoT3Large, &grpcEoM44XLarge}
-	nodeGroupIDOptionMap := map[string]expander.Option{
-		eoT2Micro.NodeGroup.Id():   eoT2Micro,
-		eoT2Large.NodeGroup.Id():   eoT2Large,
-		eoT3Large.NodeGroup.Id():   eoT3Large,
-		eoM44XLarge.NodeGroup.Id(): eoM44XLarge,
+	testCases := []struct {
+		desc                  string
+		responseOptions       []*protos.Option
+		expectedOptions       []expander.Option
+		nodegroupIDOptionaMap map[string]expander.Option
+	}{
+		{
+			desc:            "valid transform and sanitize options",
+			responseOptions: []*protos.Option{&grpcEoT2Micro, &grpcEoT3Large, &grpcEoM44XLarge},
+			nodegroupIDOptionaMap: map[string]expander.Option{
+				eoT2Micro.NodeGroup.Id():   eoT2Micro,
+				eoT2Large.NodeGroup.Id():   eoT2Large,
+				eoT3Large.NodeGroup.Id():   eoT3Large,
+				eoM44XLarge.NodeGroup.Id(): eoM44XLarge,
+			},
+			expectedOptions: []expander.Option{eoT2Micro, eoT3Large, eoM44XLarge},
+		},
+		{
+			desc:            "similar ngs are retained in proto options are retained",
+			responseOptions: []*protos.Option{&grpcEoT2MicroWithSimilar},
+			nodegroupIDOptionaMap: map[string]expander.Option{
+				eoT2MicroWithSimilar.NodeGroup.Id(): eoT2MicroWithSimilar,
+			},
+			expectedOptions: []expander.Option{eoT2MicroWithSimilar},
+		},
+		{
+			desc:            "extra similar ngs added to expander response are ignored",
+			responseOptions: []*protos.Option{&grpcEoT2MicroWithSimilarWithExtraOptions},
+			nodegroupIDOptionaMap: map[string]expander.Option{
+				eoT2MicroWithSimilar.NodeGroup.Id(): eoT2MicroWithSimilar,
+			},
+			expectedOptions: []expander.Option{eoT2MicroWithSimilar},
+		},
+	}
+	for _, tc := range testCases {
+		ret := transformAndSanitizeOptionsFromGRPC(tc.responseOptions, tc.nodegroupIDOptionaMap)
+		assert.Equal(t, tc.expectedOptions, ret)
 	}
-
-	expectedOptions := []expander.Option{eoT2Micro, eoT3Large, eoM44XLarge}
-
-	ret := transformAndSanitizeOptionsFromGRPC(responseOptionsSlice, nodeGroupIDOptionMap)
-	assert.Equal(t, expectedOptions, ret)
 }
 
 func TestAnInvalidTransformAndSanitizeOptionsFromGRPC(t *testing.T) {