diff --git a/pkg/cloudprovider/providers/azure/azure_backoff.go b/pkg/cloudprovider/providers/azure/azure_backoff.go
index 33fc9064095..0494201b6b2 100644
--- a/pkg/cloudprovider/providers/azure/azure_backoff.go
+++ b/pkg/cloudprovider/providers/azure/azure_backoff.go
@@ -58,23 +58,6 @@ func (az *Cloud) GetVirtualMachineWithRetry(name types.NodeName) (compute.Virtua
 	return machine, exists, err
 }
 
-// GetScaleSetsVMWithRetry invokes ss.getScaleSetVM with exponential backoff retry
-func (ss *scaleSet) GetScaleSetsVMWithRetry(name types.NodeName, scaleSetName string) (compute.VirtualMachineScaleSetVM, bool, error) {
-	var machine compute.VirtualMachineScaleSetVM
-	var exists bool
-	err := wait.ExponentialBackoff(ss.resourceRequestBackoff, func() (bool, error) {
-		var retryErr error
-		machine, exists, retryErr = ss.getScaleSetVM(string(name), scaleSetName)
-		if retryErr != nil {
-			glog.Errorf("GetScaleSetsVMWithRetry backoff: failure, will retry,err=%v", retryErr)
-			return false, nil
-		}
-		glog.V(10).Infof("GetScaleSetsVMWithRetry backoff: success")
-		return true, nil
-	})
-	return machine, exists, err
-}
-
 // VirtualMachineClientGetWithRetry invokes az.VirtualMachinesClient.Get with exponential backoff retry
 func (az *Cloud) VirtualMachineClientGetWithRetry(resourceGroup, vmName string, types compute.InstanceViewTypes) (compute.VirtualMachine, error) {
 	var machine compute.VirtualMachine
diff --git a/pkg/cloudprovider/providers/azure/azure_loadbalancer.go b/pkg/cloudprovider/providers/azure/azure_loadbalancer.go
index 54e108fcc84..d6f4bdfac38 100644
--- a/pkg/cloudprovider/providers/azure/azure_loadbalancer.go
+++ b/pkg/cloudprovider/providers/azure/azure_loadbalancer.go
@@ -753,12 +753,18 @@ func (az *Cloud) reconcileLoadBalancer(clusterName string, service *v1.Service,
 
 			// Remove backend pools from vmSets. This is required for virtual machine scale sets before removing the LB.
 			vmSetName := az.mapLoadBalancerNameToVMSet(lbName, clusterName)
-			az.vmSet.EnsureBackendPoolDeleted(lbBackendPoolID, vmSetName)
+			glog.V(10).Infof("EnsureBackendPoolDeleted(%s, %s): start", lbBackendPoolID, vmSetName)
+			err := az.vmSet.EnsureBackendPoolDeleted(lbBackendPoolID, vmSetName)
+			if err != nil {
+				glog.Errorf("EnsureBackendPoolDeleted(%s, %s) failed: %v", lbBackendPoolID, vmSetName, err)
+				return nil, err
+			}
+			glog.V(10).Infof("EnsureBackendPoolDeleted(%s, %s): end", lbBackendPoolID, vmSetName)
 
 			// Remove the LB.
 			az.operationPollRateLimiter.Accept()
 			glog.V(10).Infof("LoadBalancerClient.Delete(%q): start", lbName)
-			err := az.DeleteLBWithRetry(lbName)
+			err = az.DeleteLBWithRetry(lbName)
 			if err != nil {
 				glog.V(2).Infof("delete(%s) abort backoff: lb(%s) - deleting; no remaining frontendipconfigs", serviceName, lbName)
 				return nil, err
diff --git a/pkg/cloudprovider/providers/azure/azure_util_vmss.go b/pkg/cloudprovider/providers/azure/azure_util_vmss.go
index 45f631af951..71a881c9fef 100644
--- a/pkg/cloudprovider/providers/azure/azure_util_vmss.go
+++ b/pkg/cloudprovider/providers/azure/azure_util_vmss.go
@@ -23,6 +23,8 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"sync"
+	"time"
 
 	"github.com/Azure/azure-sdk-for-go/arm/compute"
 	"github.com/Azure/azure-sdk-for-go/arm/network"
@@ -40,9 +42,29 @@ var (
 	// ErrorNotVmssInstance indicates an instance is not belongint to any vmss.
 	ErrorNotVmssInstance = errors.New("not a vmss instance")
 
-	scaleSetNameRE = regexp.MustCompile(`^/subscriptions/(?:.*)/Microsoft.Compute/virtualMachineScaleSets/(.+)/virtualMachines(?:.*)`)
+	scaleSetNameRE = regexp.MustCompile(`.*/subscriptions/(?:.*)/Microsoft.Compute/virtualMachineScaleSets/(.+)/virtualMachines(?:.*)`)
 )
 
+// scaleSetVMInfo includes basic information of a virtual machine.
+type scaleSetVMInfo struct {
+	// The ID of the machine.
+	ID string
+	// Instance ID of the machine (only for scale sets vm).
+	InstanceID string
+	// Node name of the machine.
+	NodeName string
+	// Set name of the machine.
+	ScaleSetName string
+	// The type of the machine.
+	Type string
+	// The region of the machine.
+	Region string
+	// Primary interface ID of the machine.
+	PrimaryInterfaceID string
+	// Fault domain of the machine.
+	FaultDomain string
+}
+
 // scaleSet implements VMSet interface for Azure scale set.
 type scaleSet struct {
 	*Cloud
@@ -50,23 +72,173 @@ type scaleSet struct {
 	// availabilitySet is also required for scaleSet because some instances
 	// (e.g. master nodes) may not belong to any scale sets.
 	availabilitySet VMSet
+
+	cacheMutex sync.Mutex
+	// A local cache of scale sets. The key is scale set name and the value is a
+	// list of virtual machines belonging to the scale set.
+	cache map[string][]scaleSetVMInfo
 }
 
 // newScaleSet creates a new scaleSet.
 func newScaleSet(az *Cloud) VMSet {
-	return &scaleSet{
+	ss := &scaleSet{
 		Cloud:           az,
 		availabilitySet: newAvailabilitySet(az),
+		cache:           make(map[string][]scaleSetVMInfo),
 	}
+
+	go wait.Until(func() {
+		ss.cacheMutex.Lock()
+		defer ss.cacheMutex.Unlock()
+
+		if err := ss.updateCache(); err != nil {
+			glog.Errorf("updateCache failed: %v", err)
+		}
+	}, 5*time.Minute, wait.NeverStop)
+
+	return ss
+}
+
+// updateCache updates scale sets cache. It should be called within a lock.
+func (ss *scaleSet) updateCache() error {
+	scaleSetNames, err := ss.listScaleSetsWithRetry()
+	if err != nil {
+		return err
+	}
+
+	localCache := make(map[string][]scaleSetVMInfo)
+	for _, scaleSetName := range scaleSetNames {
+		if _, ok := localCache[scaleSetName]; !ok {
+			localCache[scaleSetName] = make([]scaleSetVMInfo, 0)
+		}
+		vms, err := ss.listScaleSetVMsWithRetry(scaleSetName)
+		if err != nil {
+			return err
+		}
+
+		for _, vm := range vms {
+			nodeName := ""
+			if vm.OsProfile != nil && vm.OsProfile.ComputerName != nil {
+				nodeName = *vm.OsProfile.ComputerName
+			}
+
+			vmSize := ""
+			if vm.Sku != nil && vm.Sku.Name != nil {
+				vmSize = *vm.Sku.Name
+			}
+
+			primaryInterfaceID, err := ss.getPrimaryInterfaceID(vm)
+			if err != nil {
+				glog.Errorf("getPrimaryInterfaceID for %s failed: %v", nodeName, err)
+				return err
+			}
+
+			faultDomain := ""
+			if vm.InstanceView != nil && vm.InstanceView.PlatformFaultDomain != nil {
+				faultDomain = strconv.Itoa(int(*vm.InstanceView.PlatformFaultDomain))
+			}
+
+			localCache[scaleSetName] = append(localCache[scaleSetName], scaleSetVMInfo{
+				ID:                 *vm.ID,
+				Type:               vmSize,
+				NodeName:           nodeName,
+				FaultDomain:        faultDomain,
+				ScaleSetName:       scaleSetName,
+				Region:             *vm.Location,
+				InstanceID:         *vm.InstanceID,
+				PrimaryInterfaceID: primaryInterfaceID,
+			})
+		}
+	}
+
+	// Only update cache after all steps are success.
+	ss.cache = localCache
+
+	return nil
+}
+
+// getCachedVirtualMachine gets virtualMachine by nodeName from cache.
+func (ss *scaleSet) getCachedVirtualMachine(nodeName string) (scaleSetVMInfo, error) {
+	ss.cacheMutex.Lock()
+	defer ss.cacheMutex.Unlock()
+
+	getVMFromCache := func(nodeName string) (scaleSetVMInfo, error) {
+		for scaleSetName := range ss.cache {
+			for _, vm := range ss.cache[scaleSetName] {
+				if vm.NodeName == nodeName {
+					return vm, nil
+				}
+			}
+		}
+
+		return scaleSetVMInfo{}, cloudprovider.InstanceNotFound
+	}
+
+	vm, err := getVMFromCache(nodeName)
+	if err == nil {
+		return vm, nil
+	}
+
+	// Update cache and try again.
+	if err = ss.updateCache(); err != nil {
+		return scaleSetVMInfo{}, err
+	}
+	vm, err = getVMFromCache(nodeName)
+	if err == nil {
+		return vm, nil
+	}
+
+	return scaleSetVMInfo{}, cloudprovider.InstanceNotFound
+}
+
+func (ss *scaleSet) getCachedVirtualMachineByInstanceID(scaleSetName, instanceID string) (scaleSetVMInfo, error) {
+	ss.cacheMutex.Lock()
+	defer ss.cacheMutex.Unlock()
+
+	getVMByID := func(scaleSetName, instanceID string) (scaleSetVMInfo, error) {
+		vms, ok := ss.cache[scaleSetName]
+		if !ok {
+			glog.V(4).Infof("scale set (%s) not found", scaleSetName)
+			return scaleSetVMInfo{}, cloudprovider.InstanceNotFound
+		}
+
+		for _, vm := range vms {
+			if vm.InstanceID == instanceID {
+				glog.V(4).Infof("getCachedVirtualMachineByInstanceID gets vm (%s) by instanceID (%s) within scale set (%s)", vm.NodeName, instanceID, scaleSetName)
+				return vm, nil
+			}
+		}
+
+		glog.V(4).Infof("instanceID (%s) not found in scale set (%s)", instanceID, scaleSetName)
+		return scaleSetVMInfo{}, cloudprovider.InstanceNotFound
+	}
+
+	vm, err := getVMByID(scaleSetName, instanceID)
+	if err == nil {
+		return vm, nil
+	}
+
+	// Update cache and try again.
+	if err = ss.updateCache(); err != nil {
+		return scaleSetVMInfo{}, err
+	}
+	vm, err = getVMByID(scaleSetName, instanceID)
+	if err == nil {
+		return vm, nil
+	}
+
+	return scaleSetVMInfo{}, cloudprovider.InstanceNotFound
 }
 
 // GetInstanceIDByNodeName gets the cloud provider ID by node name.
 // It must return ("", cloudprovider.InstanceNotFound) if the instance does
 // not exist or is no longer running.
 func (ss *scaleSet) GetInstanceIDByNodeName(name string) (string, error) {
-	instanceID, err := ss.getScaleSetInstanceIDByName(name, ss.PrimaryScaleSetName)
+	vm, err := ss.getCachedVirtualMachine(name)
 	if err != nil {
-		if err == cloudprovider.InstanceNotFound || err == ErrorNotVmssInstance {
+		if err == cloudprovider.InstanceNotFound {
+			glog.V(4).Infof("GetInstanceIDByNodeName: node %q is not found in scale sets, assuming it is managed by availability set", name)
+
 			// Retry with standard type because master nodes may not belong to any vmss.
 			// TODO: find a better way to identify the type of VM.
 			return ss.availabilitySet.GetInstanceIDByNodeName(name)
@@ -75,89 +247,39 @@ func (ss *scaleSet) GetInstanceIDByNodeName(name string) (string, error) {
 		return "", err
 	}
 
-	return instanceID, nil
-}
-
-func (ss *scaleSet) getScaleSetInstanceIDByName(name, scaleSetName string) (string, error) {
-	var machine compute.VirtualMachineScaleSetVM
-	var exists bool
-	var err error
-
-	ss.operationPollRateLimiter.Accept()
-	machine, exists, err = ss.getScaleSetVM(name, scaleSetName)
-	if err != nil {
-		if ss.CloudProviderBackoff {
-			glog.V(2).Infof("InstanceID(%s) backing off", name)
-			machine, exists, err = ss.GetScaleSetsVMWithRetry(types.NodeName(name), scaleSetName)
-			if err != nil {
-				glog.V(2).Infof("InstanceID(%s) abort backoff", name)
-				return "", err
-			}
-		} else {
-			return "", err
-		}
-	} else if !exists {
-		return "", cloudprovider.InstanceNotFound
-	}
-
-	return *machine.ID, nil
-}
-
-func (ss *scaleSet) getScaleSetVM(nodeName, scaleSetName string) (vm compute.VirtualMachineScaleSetVM, exists bool, err error) {
-	instanceID, err := getScaleSetVMInstanceID(nodeName)
-	if err != nil {
-		return vm, false, err
-	}
-
-	return ss.getScaleSetVMByID(instanceID, scaleSetName)
-}
-
-func (ss *scaleSet) getScaleSetVMByID(instanceID, scaleSetName string) (vm compute.VirtualMachineScaleSetVM, exists bool, err error) {
-	var realErr error
-
-	// scaleSetName is required to query VM info.
-	if scaleSetName == "" {
-		scaleSetName = ss.PrimaryScaleSetName
-	}
-
-	ss.operationPollRateLimiter.Accept()
-	glog.V(10).Infof("VirtualMachineScaleSetVMsClient.Get(%s): start", instanceID)
-	vm, err = ss.VirtualMachineScaleSetVMsClient.Get(ss.ResourceGroup, scaleSetName, instanceID)
-	glog.V(10).Infof("VirtualMachineScaleSetVMsClient.Get(%s): end", instanceID)
-
-	exists, realErr = checkResourceExistsFromError(err)
-	if realErr != nil {
-		return vm, false, realErr
-	}
-
-	if !exists {
-		return vm, false, nil
-	}
-
-	return vm, exists, err
+	return vm.ID, nil
 }
 
 // GetNodeNameByProviderID gets the node name by provider ID.
 func (ss *scaleSet) GetNodeNameByProviderID(providerID string) (types.NodeName, error) {
 	// NodeName is not part of providerID for vmss instances.
-	parts := strings.Split(providerID, "/")
-	instanceID := parts[len(parts)-1]
-	machine, exist, err := ss.getScaleSetVMByID(instanceID, ss.PrimaryScaleSetName)
-	if !exist {
-		return "", cloudprovider.InstanceNotFound
+	scaleSetName, err := extractScaleSetNameByVMID(providerID)
+	if err != nil {
+		glog.V(4).Infof("Can not extract scale set name from providerID (%s), assuming it is mananaged by availability set: %v", providerID, err)
+		return ss.availabilitySet.GetNodeNameByProviderID(providerID)
 	}
+
+	instanceID, err := getLastSegment(providerID)
+	if err != nil {
+		glog.V(4).Infof("Can not extract instanceID from providerID (%s), assuming it is mananaged by availability set: %v", providerID, err)
+		return ss.availabilitySet.GetNodeNameByProviderID(providerID)
+	}
+
+	vm, err := ss.getCachedVirtualMachineByInstanceID(scaleSetName, instanceID)
 	if err != nil {
 		return "", err
 	}
 
-	return types.NodeName(*machine.OsProfile.ComputerName), nil
+	return types.NodeName(vm.NodeName), nil
 }
 
 // GetInstanceTypeByNodeName gets the instance type by node name.
 func (ss *scaleSet) GetInstanceTypeByNodeName(name string) (string, error) {
-	instanceType, err := ss.getScaleSetInstanceTypeByNodeName(name)
+	vm, err := ss.getCachedVirtualMachine(name)
 	if err != nil {
-		if err == cloudprovider.InstanceNotFound || err == ErrorNotVmssInstance {
+		if err == cloudprovider.InstanceNotFound {
+			glog.V(4).Infof("GetInstanceTypeByNodeName: node %q is not found in scale sets, assuming it is managed by availability set", name)
+
 			// Retry with standard type because master nodes may not belong to any vmss.
 			// TODO: find a better way to identify the type of VM.
 			return ss.availabilitySet.GetInstanceTypeByNodeName(name)
@@ -166,30 +288,15 @@ func (ss *scaleSet) GetInstanceTypeByNodeName(name string) (string, error) {
 		return "", err
 	}
 
-	return instanceType, nil
-}
-
-func (ss *scaleSet) getScaleSetInstanceTypeByNodeName(name string) (string, error) {
-	machine, exists, err := ss.getScaleSetVM(name, ss.PrimaryScaleSetName)
-	if err != nil {
-		glog.Errorf("error: ss.getScaleSetInstanceTypeByNodeName(%s), ss.getScaleSetVM(%s) err=%v", name, name, err)
-		return "", err
-	} else if !exists {
-		return "", cloudprovider.InstanceNotFound
-	}
-
-	if machine.Sku.Name != nil {
-		return *machine.Sku.Name, nil
-	}
-
-	return "", fmt.Errorf("instance type is not defined")
+	return vm.Type, nil
 }
 
 // GetZoneByNodeName gets cloudprovider.Zone by node name.
 func (ss *scaleSet) GetZoneByNodeName(name string) (cloudprovider.Zone, error) {
-	instanceID, err := getScaleSetVMInstanceID(name)
+	vm, err := ss.getCachedVirtualMachine(name)
 	if err != nil {
-		if err == ErrorNotVmssInstance {
+		if err == cloudprovider.InstanceNotFound {
+			glog.V(4).Infof("GetZoneByNodeName: node %q is not found in scale sets, assuming it is managed by availability set", name)
 			// Retry with standard type because master nodes may not belong to any vmss.
 			// TODO: find a better way to identify the type of VM.
 			return ss.availabilitySet.GetZoneByNodeName(name)
@@ -197,23 +304,10 @@ func (ss *scaleSet) GetZoneByNodeName(name string) (cloudprovider.Zone, error) {
 		return cloudprovider.Zone{}, err
 	}
 
-	vm, err := ss.VirtualMachineScaleSetVMsClient.Get(ss.ResourceGroup, ss.Config.PrimaryScaleSetName, instanceID)
-	if err != nil {
-		return cloudprovider.Zone{}, err
-	}
-
-	// PlatformFaultDomain is not included in VirtualMachineScaleSetVM, so we get it from VirtualMachineScaleSetVMInstanceView.
-	vmView, err := ss.VirtualMachineScaleSetVMsClient.GetInstanceView(ss.ResourceGroup, ss.Config.PrimaryScaleSetName, instanceID)
-	if err != nil {
-		return cloudprovider.Zone{}, err
-	}
-
-	failureDomain := strconv.Itoa(int(*vmView.PlatformFaultDomain))
-	zone := cloudprovider.Zone{
-		FailureDomain: failureDomain,
-		Region:        *(vm.Location),
-	}
-	return zone, nil
+	return cloudprovider.Zone{
+		FailureDomain: vm.FaultDomain,
+		Region:        vm.Region,
+	}, nil
 }
 
 // GetPrimaryVMSetName returns the VM set name depending on the configured vmType.
@@ -345,7 +439,7 @@ func (ss *scaleSet) listScaleSetVMsWithRetry(scaleSetName string) ([]compute.Vir
 	backoffError := wait.ExponentialBackoff(ss.requestBackoff(), func() (bool, error) {
 		ss.operationPollRateLimiter.Accept()
 		glog.V(10).Infof("VirtualMachineScaleSetVMsClient.List start for %v", scaleSetName)
-		result, err = ss.VirtualMachineScaleSetVMsClient.List(ss.ResourceGroup, scaleSetName, "", "", "")
+		result, err = ss.VirtualMachineScaleSetVMsClient.List(ss.ResourceGroup, scaleSetName, "", "", string(compute.InstanceView))
 		glog.V(10).Infof("VirtualMachineScaleSetVMsClient.List end for %v", scaleSetName)
 		if err != nil {
 			glog.Errorf("VirtualMachineScaleSetVMsClient.List for %v failed: %v", scaleSetName, err)
@@ -388,25 +482,24 @@ func (ss *scaleSet) listScaleSetVMsWithRetry(scaleSetName string) ([]compute.Vir
 	return allVMs, nil
 }
 
-// getAgentPoolAvailabiliySets lists the virtual machines for for the resource group and then builds
-// a list of availability sets that match the nodes available to k8s.
+// getAgentPoolScaleSets lists the virtual machines for for the resource group and then builds
+// a list of scale sets that match the nodes available to k8s.
 func (ss *scaleSet) getAgentPoolScaleSets(nodes []*v1.Node) (*[]string, error) {
-	scaleSetNames, err := ss.listScaleSetsWithRetry()
-	if err != nil {
+	ss.cacheMutex.Lock()
+	defer ss.cacheMutex.Unlock()
+
+	// Always update cache to get latest lists of scale sets and virtual machines.
+	if err := ss.updateCache(); err != nil {
 		return nil, err
 	}
 
-	vmNameToScaleSetName := make(map[string]string, len(scaleSetNames))
-	for _, scaleSetName := range scaleSetNames {
-		vms, err := ss.listScaleSetVMsWithRetry(scaleSetName)
-		if err != nil {
-			return nil, err
-		}
-
+	vmNameToScaleSetName := make(map[string]string)
+	for scaleSetName := range ss.cache {
+		vms := ss.cache[scaleSetName]
 		for idx := range vms {
 			vm := vms[idx]
-			if vm.OsProfile != nil || vm.OsProfile.ComputerName != nil {
-				vmNameToScaleSetName[*vm.OsProfile.ComputerName] = scaleSetName
+			if vm.NodeName != "" {
+				vmNameToScaleSetName[vm.NodeName] = scaleSetName
 			}
 		}
 	}
@@ -488,43 +581,42 @@ func (ss *scaleSet) GetVMSetNames(service *v1.Service, nodes []*v1.Node) (vmSetN
 
 // GetPrimaryInterface gets machine primary network interface by node name and vmSet.
 func (ss *scaleSet) GetPrimaryInterface(nodeName, vmSetName string) (network.Interface, error) {
-	ss.operationPollRateLimiter.Accept()
-	machine, exists, err := ss.getScaleSetVM(nodeName, vmSetName)
-	if !exists || err == cloudprovider.InstanceNotFound || err == ErrorNotVmssInstance {
-		// Retry with standard type because master nodes may not belong to any vmss.
-		// TODO: find a better way to identify the type of VM.
-		return ss.availabilitySet.GetPrimaryInterface(nodeName, "")
-	}
+	vm, err := ss.getCachedVirtualMachine(nodeName)
 	if err != nil {
-		glog.Errorf("error: ss.GetPrimaryInterface(%s), ss.getScaleSetVM(%s), err=%v", nodeName, nodeName, err)
+		if err == cloudprovider.InstanceNotFound {
+			// Retry with standard type because master nodes may not belong to any vmss.
+			// TODO: find a better way to identify the type of VM.
+			return ss.availabilitySet.GetPrimaryInterface(nodeName, "")
+		}
+
+		glog.Errorf("error: ss.GetPrimaryInterface(%s), ss.getCachedVirtualMachine(%s), err=%v", nodeName, nodeName, err)
 		return network.Interface{}, err
 	}
 
-	nicID, err := ss.getPrimaryInterfaceID(machine)
-	if err != nil {
-		glog.Errorf("error: ss.GetPrimaryInterface(%s), getPrimaryInterfaceID(%v), err=%v", nodeName, machine, err)
-		return network.Interface{}, err
+	// Check scale set name.
+	if vmSetName != "" && !strings.EqualFold(vm.ScaleSetName, vmSetName) {
+		return network.Interface{}, errNotInVMSet
 	}
 
-	nicName, err := getLastSegment(nicID)
+	nicName, err := getLastSegment(vm.PrimaryInterfaceID)
 	if err != nil {
-		glog.Errorf("error: ss.GetPrimaryInterface(%s), getLastSegment(%s), err=%v", nodeName, nicID, err)
+		glog.Errorf("error: ss.GetPrimaryInterface(%s), getLastSegment(%s), err=%v", nodeName, vm.PrimaryInterfaceID, err)
 		return network.Interface{}, err
 	}
 
 	ss.operationPollRateLimiter.Accept()
 	glog.V(10).Infof("InterfacesClient.Get(%q): start", nicName)
-	nic, err := ss.InterfacesClient.GetVirtualMachineScaleSetNetworkInterface(ss.ResourceGroup, ss.Config.PrimaryScaleSetName, *machine.InstanceID, nicName, "")
+	nic, err := ss.InterfacesClient.GetVirtualMachineScaleSetNetworkInterface(ss.ResourceGroup, vm.ScaleSetName, vm.InstanceID, nicName, "")
 	glog.V(10).Infof("InterfacesClient.Get(%q): end", nicName)
 	if err != nil {
-		glog.Errorf("error: ss.GetPrimaryInterface(%s), ss.GetVirtualMachineScaleSetNetworkInterface.Get(%s, %s, %s), err=%v", nodeName, ss.ResourceGroup, nicName, "", err)
+		glog.Errorf("error: ss.GetPrimaryInterface(%s), ss.GetVirtualMachineScaleSetNetworkInterface.Get(%s, %s, %s), err=%v", nodeName, ss.ResourceGroup, vm.ScaleSetName, nicName, err)
 		return network.Interface{}, err
 	}
 
 	// Fix interface's location, which is required when updating the interface.
 	// TODO: is this a bug of azure SDK?
 	if nic.Location == nil || *nic.Location == "" {
-		nic.Location = &ss.Config.Location
+		nic.Location = &vm.Region
 	}
 
 	return nic, nil