bootstrapper: prioritize etcd disk I/O (#3114)

bootstrapper/cmd/bootstrapper/main.go

@@ -86,7 +86,7 @@ func main() {
 
 		clusterInitJoiner = kubernetes.New(
 			"aws", k8sapi.NewKubernetesUtil(), &k8sapi.KubdeadmConfiguration{}, kubectl.NewUninitialized(),
-			metadata, &kubewaiter.CloudKubeAPIWaiter{},
+			metadata, &kubewaiter.CloudKubeAPIWaiter{}, log,
 		)
 		openDevice = vtpm.OpenVTPM
 		fs = afero.NewOsFs()
@@ -102,7 +102,7 @@ func main() {
 		metadataAPI = metadata
 		clusterInitJoiner = kubernetes.New(
 			"gcp", k8sapi.NewKubernetesUtil(), &k8sapi.KubdeadmConfiguration{}, kubectl.NewUninitialized(),
-			metadata, &kubewaiter.CloudKubeAPIWaiter{},
+			metadata, &kubewaiter.CloudKubeAPIWaiter{}, log,
 		)
 		openDevice = vtpm.OpenVTPM
 		fs = afero.NewOsFs()
@@ -122,7 +122,7 @@ func main() {
 		metadataAPI = metadata
 		clusterInitJoiner = kubernetes.New(
 			"azure", k8sapi.NewKubernetesUtil(), &k8sapi.KubdeadmConfiguration{}, kubectl.NewUninitialized(),
-			metadata, &kubewaiter.CloudKubeAPIWaiter{},
+			metadata, &kubewaiter.CloudKubeAPIWaiter{}, log,
 		)
 
 		openDevice = vtpm.OpenVTPM
@@ -132,7 +132,7 @@ func main() {
 		metadata := qemucloud.New()
 		clusterInitJoiner = kubernetes.New(
 			"qemu", k8sapi.NewKubernetesUtil(), &k8sapi.KubdeadmConfiguration{}, kubectl.NewUninitialized(),
-			metadata, &kubewaiter.CloudKubeAPIWaiter{},
+			metadata, &kubewaiter.CloudKubeAPIWaiter{}, log,
 		)
 		metadataAPI = metadata
 
@@ -155,7 +155,7 @@ func main() {
 		}
 		clusterInitJoiner = kubernetes.New(
 			"openstack", k8sapi.NewKubernetesUtil(), &k8sapi.KubdeadmConfiguration{}, kubectl.NewUninitialized(),
-			metadata, &kubewaiter.CloudKubeAPIWaiter{},
+			metadata, &kubewaiter.CloudKubeAPIWaiter{}, log,
 		)
 		metadataAPI = metadata
 		openDevice = vtpm.OpenVTPM

bootstrapper/cmd/bootstrapper/test.go

@@ -8,7 +8,6 @@ package main
 
 import (
 	"context"
-	"log/slog"
 
 	"github.com/edgelesssys/constellation/v2/internal/cloud/metadata"
 	"github.com/edgelesssys/constellation/v2/internal/role"
@@ -22,13 +21,13 @@ type clusterFake struct{}
 // InitCluster fakes bootstrapping a new cluster with the current node being the master, returning the arguments required to join the cluster.
 func (c *clusterFake) InitCluster(
 	context.Context, string, string,
-	bool, components.Components, []string, string, *slog.Logger,
+	bool, components.Components, []string, string,
 ) ([]byte, error) {
 	return []byte{}, nil
 }
 
 // JoinCluster will fake joining the current node to an existing cluster.
-func (c *clusterFake) JoinCluster(context.Context, *kubeadm.BootstrapTokenDiscovery, role.Role, components.Components, *slog.Logger) error {
+func (c *clusterFake) JoinCluster(context.Context, *kubeadm.BootstrapTokenDiscovery, role.Role, components.Components) error {
 	return nil
 }
 

bootstrapper/internal/etcdio/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "etcdio",
+    srcs = ["etcdio.go"],
+    importpath = "github.com/edgelesssys/constellation/v2/bootstrapper/internal/etcdio",
+    visibility = ["//bootstrapper:__subpackages__"],
+    deps = ["@org_golang_x_sys//unix"],
+)

bootstrapper/internal/etcdio/etcdio.go

@@ -0,0 +1,156 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+// The etcdio package provides utilities to manage etcd I/O.
+package etcdio
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log/slog"
+	"os"
+	"path"
+	"strconv"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+var (
+	// ErrNoEtcdProcess is returned when no etcd process is found on the node.
+	ErrNoEtcdProcess = errors.New("no etcd process found on node")
+	// ErrMultipleEtcdProcesses is returned when multiple etcd processes are found on the node.
+	ErrMultipleEtcdProcesses = errors.New("multiple etcd processes found on node")
+)
+
+const (
+	// Tells the syscall that a process' priority is going to be set.
+	// See https://elixir.bootlin.com/linux/v6.9.1/source/include/uapi/linux/ioprio.h#L54.
+	ioPrioWhoProcess = 1
+
+	// See https://elixir.bootlin.com/linux/v6.9.1/source/include/uapi/linux/ioprio.h#L11.
+	ioPrioClassShift = 13
+	ioPrioNrClasses  = 8
+	ioPrioClassMask  = ioPrioNrClasses - 1
+	ioPrioPrioMask   = (1 << ioPrioClassShift) - 1
+
+	targetClass = 1 // Realtime IO class for best scheduling prio
+	targetPrio  = 0 // Highest priority within the class
+)
+
+// Client is a client for managing etcd I/O.
+type Client struct {
+	log *slog.Logger
+}
+
+// NewClient creates a new etcd I/O management client.
+func NewClient(log *slog.Logger) *Client {
+	return &Client{log: log}
+}
+
+// PrioritizeIO tries to prioritize the I/O of the etcd process.
+// Since it might be possible that the process just started (if this method is called
+// right after the kubelet started), it retries to do its work each second
+// until it succeeds or the timeout of 10 seconds is reached.
+func (c *Client) PrioritizeIO() {
+	ticker := time.NewTicker(1 * time.Second)
+	defer ticker.Stop()
+	timeout, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	for {
+		c.log.Info("Prioritizing etcd I/O")
+		err := c.setIOPriority()
+		if err == nil {
+			// Success, return directly
+			return
+		} else if errors.Is(err, ErrNoEtcdProcess) {
+			c.log.Info("No etcd process found, retrying")
+		} else {
+			c.log.Warn("Prioritizing etcd I/O failed", "error", err)
+			return
+		}
+
+		select {
+		case <-ticker.C:
+		case <-timeout.Done():
+			c.log.Warn("Timed out waiting for etcd to start")
+			return
+		}
+	}
+}
+
+// setIOPriority tries to find the etcd process on the node and prioritizes its I/O.
+func (c *Client) setIOPriority() error {
+	// find etcd process(es)
+	pid, err := c.findEtcdProcess()
+	if err != nil {
+		return fmt.Errorf("finding etcd process: %w", err)
+	}
+
+	// Highest realtime priority value for the etcd process, see https://elixir.bootlin.com/linux/v6.9.1/source/include/uapi/linux/ioprio.h
+	// for the calculation details.
+	prioVal := ((targetClass & ioPrioClassMask) << ioPrioClassShift) | (targetPrio & ioPrioPrioMask)
+
+	// see https://man7.org/linux/man-pages/man2/ioprio_set.2.html
+	ret, _, errno := unix.Syscall(unix.SYS_IOPRIO_SET, ioPrioWhoProcess, uintptr(pid), uintptr(prioVal))
+	if ret != 0 {
+		return fmt.Errorf("setting I/O priority for etcd: %w", errno)
+	}
+
+	return nil
+}
+
+// findEtcdProcess tries to find the etcd process on the node.
+func (c *Client) findEtcdProcess() (int, error) {
+	procDir, err := os.Open("/proc")
+	if err != nil {
+		return 0, fmt.Errorf("opening /proc: %w", err)
+	}
+	defer procDir.Close()
+
+	procEntries, err := procDir.Readdirnames(0)
+	if err != nil {
+		return 0, fmt.Errorf("reading /proc: %w", err)
+	}
+
+	// find etcd process(es)
+	etcdPIDs := []int{}
+	for _, f := range procEntries {
+		// exclude non-pid dirs
+		if f[0] < '0' || f[0] > '9' {
+			continue
+		}
+
+		exe, err := os.Readlink(fmt.Sprintf("/proc/%s/exe", f))
+		if err != nil {
+			continue
+		}
+
+		if path.Base(exe) != "etcd" {
+			continue
+		}
+
+		pid, err := strconv.Atoi(f)
+		if err != nil {
+			continue
+		}
+
+		// add the PID to the list of etcd PIDs
+		etcdPIDs = append(etcdPIDs, pid)
+	}
+
+	if len(etcdPIDs) == 0 {
+		return 0, ErrNoEtcdProcess
+	}
+
+	if len(etcdPIDs) > 1 {
+		return 0, ErrMultipleEtcdProcesses
+	}
+
+	return etcdPIDs[0], nil
+}

bootstrapper/internal/initserver/initserver.go

@@ -234,7 +234,6 @@ func (s *Server) Init(req *initproto.InitRequest, stream initproto.API_InitServe
 		req.KubernetesComponents,
 		req.ApiserverCertSans,
 		req.ServiceCidr,
-		s.log,
 	)
 	if err != nil {
 		if e := s.sendLogsWithMessage(stream, status.Errorf(codes.Internal, "initializing cluster: %s", err)); e != nil {
@@ -357,7 +356,6 @@ type ClusterInitializer interface {
 		kubernetesComponents components.Components,
 		apiServerCertSANs []string,
 		serviceCIDR string,
-		log *slog.Logger,
 	) ([]byte, error)
 }
 

bootstrapper/internal/initserver/initserver_test.go

@@ -11,7 +11,6 @@ import (
 	"context"
 	"errors"
 	"io"
-	"log/slog"
 	"net"
 	"strings"
 	"sync"
@@ -420,7 +419,7 @@ type stubClusterInitializer struct {
 
 func (i *stubClusterInitializer) InitCluster(
 	context.Context, string, string,
-	bool, components.Components, []string, string, *slog.Logger,
+	bool, components.Components, []string, string,
 ) ([]byte, error) {
 	return i.initClusterKubeconfig, i.initClusterErr
 }

bootstrapper/internal/joinclient/joinclient.go

@@ -288,7 +288,7 @@ func (c *JoinClient) startNodeAndJoin(ticket *joinproto.IssueJoinTicketResponse,
 	// We currently cannot recover from any failure in this function. Joining the k8s cluster
 	// sometimes fails transiently, and we don't want to brick the node because of that.
 	for i := range 3 {
-		err = c.joiner.JoinCluster(ctx, btd, c.role, ticket.KubernetesComponents, c.log)
+		err = c.joiner.JoinCluster(ctx, btd, c.role, ticket.KubernetesComponents)
 		if err == nil {
 			break
 		}
@@ -399,7 +399,6 @@ type ClusterJoiner interface {
 		args *kubeadm.BootstrapTokenDiscovery,
 		peerRole role.Role,
 		k8sComponents components.Components,
-		log *slog.Logger,
 	) error
 }
 

bootstrapper/internal/joinclient/joinclient_test.go

@@ -8,7 +8,6 @@ package joinclient
 
 import (
 	"context"
-	"log/slog"
 	"net"
 	"strconv"
 	"sync"
@@ -350,7 +349,7 @@ type stubClusterJoiner struct {
 	joinClusterErr    error
 }
 
-func (j *stubClusterJoiner) JoinCluster(context.Context, *kubeadm.BootstrapTokenDiscovery, role.Role, components.Components, *slog.Logger) error {
+func (j *stubClusterJoiner) JoinCluster(context.Context, *kubeadm.BootstrapTokenDiscovery, role.Role, components.Components) error {
 	j.joinClusterCalled++
 	if j.numBadCalls == 0 {
 		return nil

bootstrapper/internal/kubernetes/BUILD.bazel

@@ -11,6 +11,7 @@ go_library(
     importpath = "github.com/edgelesssys/constellation/v2/bootstrapper/internal/kubernetes",
     visibility = ["//bootstrapper:__subpackages__"],
     deps = [
+        "//bootstrapper/internal/etcdio",
         "//bootstrapper/internal/kubernetes/k8sapi",
         "//bootstrapper/internal/kubernetes/kubewaiter",
         "//internal/cloud/cloudprovider",

bootstrapper/internal/kubernetes/kubernetes.go

@@ -16,6 +16,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/edgelesssys/constellation/v2/bootstrapper/internal/etcdio"
 	"github.com/edgelesssys/constellation/v2/bootstrapper/internal/kubernetes/k8sapi"
 	"github.com/edgelesssys/constellation/v2/bootstrapper/internal/kubernetes/kubewaiter"
 	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
@@ -40,6 +41,10 @@ type kubeAPIWaiter interface {
 	Wait(ctx context.Context, kubernetesClient kubewaiter.KubernetesClient) error
 }
 
+type etcdIOPrioritizer interface {
+	PrioritizeIO()
+}
+
 // KubeWrapper implements Cluster interface.
 type KubeWrapper struct {
 	cloudProvider     string
@@ -48,13 +53,18 @@ type KubeWrapper struct {
 	configProvider    configurationProvider
 	client            k8sapi.Client
 	providerMetadata  ProviderMetadata
+	etcdIOPrioritizer etcdIOPrioritizer
 	getIPAddr         func() (string, error)
+
+	log *slog.Logger
 }
 
 // New creates a new KubeWrapper with real values.
 func New(cloudProvider string, clusterUtil clusterUtil, configProvider configurationProvider, client k8sapi.Client,
-	providerMetadata ProviderMetadata, kubeAPIWaiter kubeAPIWaiter,
+	providerMetadata ProviderMetadata, kubeAPIWaiter kubeAPIWaiter, log *slog.Logger,
 ) *KubeWrapper {
+	etcdIOPrioritizer := etcdio.NewClient(log)
+
 	return &KubeWrapper{
 		cloudProvider:     cloudProvider,
 		clusterUtil:       clusterUtil,
@@ -63,14 +73,16 @@ func New(cloudProvider string, clusterUtil clusterUtil, configProvider configura
 		client:            client,
 		providerMetadata:  providerMetadata,
 		getIPAddr:         getIPAddr,
+		log:               log,
+		etcdIOPrioritizer: etcdIOPrioritizer,
 	}
 }
 
 // InitCluster initializes a new Kubernetes cluster and applies pod network provider.
 func (k *KubeWrapper) InitCluster(
-	ctx context.Context, versionString, clusterName string, conformanceMode bool, kubernetesComponents components.Components, apiServerCertSANs []string, serviceCIDR string, log *slog.Logger,
+	ctx context.Context, versionString, clusterName string, conformanceMode bool, kubernetesComponents components.Components, apiServerCertSANs []string, serviceCIDR string,
 ) ([]byte, error) {
-	log.With(slog.String("version", versionString)).Info("Installing Kubernetes components")
+	k.log.With(slog.String("version", versionString)).Info("Installing Kubernetes components")
 	if err := k.clusterUtil.InstallComponents(ctx, kubernetesComponents); err != nil {
 		return nil, err
 	}
@@ -78,7 +90,7 @@ func (k *KubeWrapper) InitCluster(
 	var validIPs []net.IP
 
 	// Step 1: retrieve cloud metadata for Kubernetes configuration
-	log.Info("Retrieving node metadata")
+	k.log.Info("Retrieving node metadata")
 	instance, err := k.providerMetadata.Self(ctx)
 	if err != nil {
 		return nil, fmt.Errorf("retrieving own instance metadata: %w", err)
@@ -106,7 +118,7 @@ func (k *KubeWrapper) InitCluster(
 	certSANs := []string{nodeIP}
 	certSANs = append(certSANs, apiServerCertSANs...)
 
-	log.With(
+	k.log.With(
 		slog.String("nodeName", nodeName),
 		slog.String("providerID", instance.ProviderID),
 		slog.String("nodeIP", nodeIP),
@@ -132,12 +144,16 @@ func (k *KubeWrapper) InitCluster(
 	if err != nil {
 		return nil, fmt.Errorf("encoding kubeadm init configuration as YAML: %w", err)
 	}
-	log.Info("Initializing Kubernetes cluster")
-	kubeConfig, err := k.clusterUtil.InitCluster(ctx, initConfigYAML, nodeName, clusterName, validIPs, conformanceMode, log)
+
+	k.log.Info("Initializing Kubernetes cluster")
+	kubeConfig, err := k.clusterUtil.InitCluster(ctx, initConfigYAML, nodeName, clusterName, validIPs, conformanceMode, k.log)
 	if err != nil {
 		return nil, fmt.Errorf("kubeadm init: %w", err)
 	}
 
+	k.log.Info("Prioritizing etcd I/O")
+	k.etcdIOPrioritizer.PrioritizeIO()
+
 	err = k.client.Initialize(kubeConfig)
 	if err != nil {
 		return nil, fmt.Errorf("initializing kubectl client: %w", err)
@@ -177,22 +193,23 @@ func (k *KubeWrapper) InitCluster(
 		return nil, fmt.Errorf("annotating node with Kubernetes components hash: %w", err)
 	}
 
-	log.Info("Setting up internal-config ConfigMap")
+	k.log.Info("Setting up internal-config ConfigMap")
 	if err := k.setupInternalConfigMap(ctx); err != nil {
 		return nil, fmt.Errorf("failed to setup internal ConfigMap: %w", err)
 	}
+
 	return kubeConfig, nil
 }
 
 // JoinCluster joins existing Kubernetes cluster.
-func (k *KubeWrapper) JoinCluster(ctx context.Context, args *kubeadm.BootstrapTokenDiscovery, peerRole role.Role, k8sComponents components.Components, log *slog.Logger) error {
-	log.With("k8sComponents", k8sComponents).Info("Installing provided kubernetes components")
+func (k *KubeWrapper) JoinCluster(ctx context.Context, args *kubeadm.BootstrapTokenDiscovery, peerRole role.Role, k8sComponents components.Components) error {
+	k.log.With("k8sComponents", k8sComponents).Info("Installing provided kubernetes components")
 	if err := k.clusterUtil.InstallComponents(ctx, k8sComponents); err != nil {
 		return fmt.Errorf("installing kubernetes components: %w", err)
 	}
 
 	// Step 1: retrieve cloud metadata for Kubernetes configuration
-	log.Info("Retrieving node metadata")
+	k.log.Info("Retrieving node metadata")
 	instance, err := k.providerMetadata.Self(ctx)
 	if err != nil {
 		return fmt.Errorf("retrieving own instance metadata: %w", err)
@@ -212,7 +229,7 @@ func (k *KubeWrapper) JoinCluster(ctx context.Context, args *kubeadm.BootstrapTo
 	// override join endpoint to go over lb
 	args.APIServerEndpoint = net.JoinHostPort(loadBalancerHost, loadBalancerPort)
 
-	log.With(
+	k.log.With(
 		slog.String("nodeName", nodeName),
 		slog.String("providerID", providerID),
 		slog.String("nodeIP", nodeInternalIP),
@@ -237,11 +254,18 @@ func (k *KubeWrapper) JoinCluster(ctx context.Context, args *kubeadm.BootstrapTo
 	if err != nil {
 		return fmt.Errorf("encoding kubeadm join configuration as YAML: %w", err)
 	}
-	log.With(slog.String("apiServerEndpoint", args.APIServerEndpoint)).Info("Joining Kubernetes cluster")
-	if err := k.clusterUtil.JoinCluster(ctx, joinConfigYAML, log); err != nil {
+
+	k.log.With(slog.String("apiServerEndpoint", args.APIServerEndpoint)).Info("Joining Kubernetes cluster")
+	if err := k.clusterUtil.JoinCluster(ctx, joinConfigYAML, k.log); err != nil {
 		return fmt.Errorf("joining cluster: %v; %w ", string(joinConfigYAML), err)
 	}
 
+	// If on control plane (and thus with etcd), try to prioritize etcd I/O.
+	if peerRole == role.ControlPlane {
+		k.log.Info("Prioritizing etcd I/O")
+		k.etcdIOPrioritizer.PrioritizeIO()
+	}
+
 	return nil
 }
 
@@ -301,6 +325,8 @@ func (k *KubeWrapper) StartKubelet() error {
 		return fmt.Errorf("starting kubelet: %w", err)
 	}
 
+	k.etcdIOPrioritizer.PrioritizeIO()
+
 	return nil
 }
 

bootstrapper/internal/kubernetes/kubernetes_test.go

@@ -47,12 +47,14 @@ func TestInitCluster(t *testing.T) {
 		kubeAPIWaiter     stubKubeAPIWaiter
 		providerMetadata  ProviderMetadata
 		wantConfig        k8sapi.KubeadmInitYAML
+		etcdIOPrioritizer stubEtcdIOPrioritizer
 		wantErr           bool
 		k8sVersion        versions.ValidK8sVersion
 	}{
 		"kubeadm init works with metadata and loadbalancer": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
 			kubeAPIWaiter:     stubKubeAPIWaiter{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				selfResp: metadata.InstanceMetadata{
 					Name:          nodeName,
@@ -87,6 +89,7 @@ func TestInitCluster(t *testing.T) {
 		"kubeadm init fails when annotating itself": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
 			kubeAPIWaiter:     stubKubeAPIWaiter{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				selfResp: metadata.InstanceMetadata{
 					Name:          nodeName,
@@ -104,6 +107,7 @@ func TestInitCluster(t *testing.T) {
 		"kubeadm init fails when retrieving metadata self": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
 			kubeAPIWaiter:     stubKubeAPIWaiter{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				selfErr: assert.AnError,
 			},
@@ -112,6 +116,7 @@ func TestInitCluster(t *testing.T) {
 		},
 		"kubeadm init fails when retrieving metadata loadbalancer ip": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				getLoadBalancerEndpointErr: assert.AnError,
 			},
@@ -124,12 +129,14 @@ func TestInitCluster(t *testing.T) {
 				kubeconfig:     []byte("someKubeconfig"),
 			},
 			kubeAPIWaiter:     stubKubeAPIWaiter{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata:  &stubProviderMetadata{},
 			wantErr:           true,
 			k8sVersion:        versions.Default,
 		},
 		"kubeadm init fails when deploying cilium": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata:  &stubProviderMetadata{},
 			wantErr:           true,
 			k8sVersion:        versions.Default,
@@ -137,6 +144,7 @@ func TestInitCluster(t *testing.T) {
 		"kubeadm init fails when setting up constellation-services chart": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
 			kubeAPIWaiter:     stubKubeAPIWaiter{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata:  &stubProviderMetadata{},
 			wantErr:           true,
 			k8sVersion:        versions.Default,
@@ -144,6 +152,7 @@ func TestInitCluster(t *testing.T) {
 		"kubeadm init fails when reading kubeconfig": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
 			kubeAPIWaiter:     stubKubeAPIWaiter{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata:  &stubProviderMetadata{},
 			wantErr:           true,
 			k8sVersion:        versions.Default,
@@ -151,6 +160,7 @@ func TestInitCluster(t *testing.T) {
 		"kubeadm init fails when setting up verification service": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
 			kubeAPIWaiter:     stubKubeAPIWaiter{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata:  &stubProviderMetadata{},
 			wantErr:           true,
 			k8sVersion:        versions.Default,
@@ -158,6 +168,7 @@ func TestInitCluster(t *testing.T) {
 		"kubeadm init fails when waiting for kubeAPI server": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
 			kubeAPIWaiter:     stubKubeAPIWaiter{waitErr: assert.AnError},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata:  &stubProviderMetadata{},
 			k8sVersion:        versions.Default,
 			wantErr:           true,
@@ -165,6 +176,7 @@ func TestInitCluster(t *testing.T) {
 		"unsupported k8sVersion fails cluster creation": {
 			clusterUtil:       stubClusterUtil{kubeconfig: []byte("someKubeconfig")},
 			kubeAPIWaiter:     stubKubeAPIWaiter{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata:  &stubProviderMetadata{},
 			k8sVersion:        "1.19",
 			wantErr:           true,
@@ -184,11 +196,13 @@ func TestInitCluster(t *testing.T) {
 				configProvider:    &stubConfigProvider{initConfig: k8sapi.KubeadmInitYAML{}},
 				client:            &tc.kubectl,
 				getIPAddr:         func() (string, error) { return privateIP, nil },
+				etcdIOPrioritizer: &tc.etcdIOPrioritizer,
+				log:               logger.NewTest(t),
 			}
 
 			_, err := kube.InitCluster(
 				context.Background(), string(tc.k8sVersion), "kubernetes",
-				false, nil, nil, "", logger.NewTest(t),
+				false, nil, nil, "",
 			)
 
 			if tc.wantErr {
@@ -229,10 +243,12 @@ func TestJoinCluster(t *testing.T) {
 		wantConfig        kubeadm.JoinConfiguration
 		role              role.Role
 		k8sComponents     components.Components
+		etcdIOPrioritizer stubEtcdIOPrioritizer
 		wantErr           bool
 	}{
 		"kubeadm join worker works with metadata and remote Kubernetes Components": {
 			clusterUtil:       stubClusterUtil{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				selfResp: metadata.InstanceMetadata{
 					ProviderID: "provider-id",
@@ -254,6 +270,7 @@ func TestJoinCluster(t *testing.T) {
 		},
 		"kubeadm join worker works with metadata and local Kubernetes components": {
 			clusterUtil:       stubClusterUtil{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				selfResp: metadata.InstanceMetadata{
 					ProviderID: "provider-id",
@@ -274,6 +291,7 @@ func TestJoinCluster(t *testing.T) {
 		},
 		"kubeadm join worker works with metadata and cloud controller manager": {
 			clusterUtil:       stubClusterUtil{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				selfResp: metadata.InstanceMetadata{
 					ProviderID: "provider-id",
@@ -294,6 +312,7 @@ func TestJoinCluster(t *testing.T) {
 		},
 		"kubeadm join control-plane node works with metadata": {
 			clusterUtil:       stubClusterUtil{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				selfResp: metadata.InstanceMetadata{
 					ProviderID: "provider-id",
@@ -321,6 +340,7 @@ func TestJoinCluster(t *testing.T) {
 		},
 		"kubeadm join worker fails when installing remote Kubernetes components": {
 			clusterUtil:       stubClusterUtil{installComponentsErr: errors.New("error")},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				selfResp: metadata.InstanceMetadata{
 					ProviderID: "provider-id",
@@ -334,6 +354,7 @@ func TestJoinCluster(t *testing.T) {
 		},
 		"kubeadm join worker fails when retrieving self metadata": {
 			clusterUtil:       stubClusterUtil{},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata: &stubProviderMetadata{
 				selfErr: assert.AnError,
 			},
@@ -342,6 +363,7 @@ func TestJoinCluster(t *testing.T) {
 		},
 		"kubeadm join worker fails when applying the join config": {
 			clusterUtil:       stubClusterUtil{joinClusterErr: assert.AnError},
+			etcdIOPrioritizer: stubEtcdIOPrioritizer{},
 			providerMetadata:  &stubProviderMetadata{},
 			role:              role.Worker,
 			wantErr:           true,
@@ -358,9 +380,11 @@ func TestJoinCluster(t *testing.T) {
 				providerMetadata:  tc.providerMetadata,
 				configProvider:    &stubConfigProvider{},
 				getIPAddr:         func() (string, error) { return privateIP, nil },
+				etcdIOPrioritizer: &tc.etcdIOPrioritizer,
+				log:               logger.NewTest(t),
 			}
 
-			err := kube.JoinCluster(context.Background(), joinCommand, tc.role, tc.k8sComponents, logger.NewTest(t))
+			err := kube.JoinCluster(context.Background(), joinCommand, tc.role, tc.k8sComponents)
 			if tc.wantErr {
 				assert.Error(err)
 				return
@@ -545,3 +569,7 @@ type stubKubeAPIWaiter struct {
 func (s *stubKubeAPIWaiter) Wait(_ context.Context, _ kubewaiter.KubernetesClient) error {
 	return s.waitErr
 }
+
+type stubEtcdIOPrioritizer struct{}
+
+func (s *stubEtcdIOPrioritizer) PrioritizeIO() {}