Allow admin user to explicitly unschedule the node

Setting Unschedulable on the node will not touch any existing pods
on the node but will block scheduling of new pods on the node.

docs/node.md

@@ -38,13 +38,16 @@ must have appropriate conditions, see below.
 
 ### Node Condition
 Node Condition describes the conditions of `Running` nodes. Current valid
-conditions are `NodeReachable` and `NodeReady`. In the future, we plan to
+conditions are `NodeReachable`, `NodeReady` and `NodeSchedulable`. In the
-add more. `NodeReachable` means the node can be reached within the cluster.
+future, we plan to add more. `NodeReachable` means the node can be reached
-`NodeReady` means the kubelet returns StatusOK for HTTP health check. Different
+within the cluster. `NodeReady` means the kubelet returns StatusOK for HTTP
-condition provides different level of understanding for node health. Kubernetes
+health check. `NodeSchedulable` means node is allowed to schedule any new
-will make a comprehensive scheduling decision based on the information. Node
+pods and is controlled by 'unschedulable' field in node spec.
-condition is represented as a json object. For example, the following conditions
+Different condition provides different level of understanding for node
-mean the node is reachable from its cluster, but not ready to accept pods:
+health. Kubernetes will make a comprehensive scheduling decision based on the
+information. Node condition is represented as a json object. For example, the
+following conditions mean the node is reachable from its cluster, node is in
+sane state but not allowed to accept new pods:
 ```json
 "conditions": [
   {
@@ -53,8 +56,12 @@ mean the node is reachable from its cluster, but not ready to accept pods:
   },
   {
     "kind": "Ready",
+    "status": "Full",
+  },
+  {
+    "kind": "Schedulable",
     "status": "None",
-  }
+  },
 ]
 ```
 
@@ -125,3 +132,9 @@ A Kubernetes administrator typically uses `kubectl` to manage `Node`. Similar
 to Node Controller, `kubectl` command only creates/deletes node representation.
 Note if Kubernetes is running on cloud provider, `kubectl create` a node will
 be refused if Node Controller has already synchronized nodes from cloud provider.
+Admin can choose to make the node unschedulable using `kubectl`. Unscheduling the node
+will not affect any existing pods on the node but it will disable creation of
+any new pods on the node. Node unschedulable example:
+```
+kubectl update nodes 10.1.2.3 --patch='{"apiVersion": "v1beta1", "unschedulable": true}'
+```

pkg/api/types.go

@@ -782,13 +782,18 @@ type EndpointsList struct {
 
 // NodeSpec describes the attributes that a node is created with.
 type NodeSpec struct {
-	// Capacity represents the available resources of a node
+	// Capacity represents the available resources of a node.
 	Capacity ResourceList `json:"capacity,omitempty"`
+
 	// PodCIDR represents the pod IP range assigned to the node
 	// Note: assigning IP ranges to nodes might need to be revisited when we support migratable IPs.
 	PodCIDR string `json:"podCIDR,omitempty"`
+
 	// External ID of the node assigned by some machine database (e.g. a cloud provider)
 	ExternalID string `json:"externalID,omitempty"`
+
+	// Unschedulable controls node schedulability of new pods. By default node is schedulable.
+	Unschedulable bool `json:"unschedulable,omitempty"`
 }
 
 // NodeSystemInfo is a set of ids/uuids to uniquely identify the node.
@@ -842,6 +847,8 @@ const (
 	NodeReachable NodeConditionType = "Reachable"
 	// NodeReady means the node returns StatusOK for HTTP health check.
 	NodeReady NodeConditionType = "Ready"
+	// NodeSchedulable means the node is ready to accept new pods.
+	NodeSchedulable NodeConditionType = "Schedulable"
 )
 
 type NodeCondition struct {

pkg/api/v1beta1/conversion.go

@@ -711,6 +711,7 @@ func init() {
 			}
 			out.PodCIDR = in.Spec.PodCIDR
 			out.ExternalID = in.Spec.ExternalID
+			out.Unschedulable = in.Spec.Unschedulable
 			return s.Convert(&in.Spec.Capacity, &out.NodeResources.Capacity, 0)
 		},
 		func(in *Minion, out *newer.Node, s conversion.Scope) error {
@@ -742,6 +743,7 @@ func init() {
 			}
 			out.Spec.PodCIDR = in.PodCIDR
 			out.Spec.ExternalID = in.ExternalID
+			out.Spec.Unschedulable = in.Unschedulable
 			return s.Convert(&in.NodeResources.Capacity, &out.Spec.Capacity, 0)
 		},
 

pkg/api/v1beta1/types.go

@@ -677,6 +677,8 @@ const (
 	NodeReachable NodeConditionKind = "Reachable"
 	// NodeReady means the node returns StatusOK for HTTP health check.
 	NodeReady NodeConditionKind = "Ready"
+	// NodeSchedulable means the node is ready to accept new pods.
+	NodeSchedulable NodeConditionKind = "Schedulable"
 )
 
 type NodeCondition struct {
@@ -731,6 +733,8 @@ type Minion struct {
 	NodeResources NodeResources `json:"resources,omitempty" description:"characterization of node resources"`
 	// Pod IP range assigned to the node
 	PodCIDR string `json:"podCIDR,omitempty" description:"IP range assigned to the node"`
+	// Unschedulable controls node schedulability of new pods. By default node is schedulable.
+	Unschedulable bool `json:"unschedulable,omitempty" description:"disable pod scheduling on the node"`
 	// Status describes the current status of a node
 	Status NodeStatus `json:"status,omitempty" description:"current status of node"`
 	// Labels for the node

pkg/api/v1beta2/conversion.go

@@ -631,6 +631,7 @@ func init() {
 			}
 			out.PodCIDR = in.Spec.PodCIDR
 			out.ExternalID = in.Spec.ExternalID
+			out.Unschedulable = in.Spec.Unschedulable
 			return s.Convert(&in.Spec.Capacity, &out.NodeResources.Capacity, 0)
 		},
 		func(in *Minion, out *newer.Node, s conversion.Scope) error {
@@ -662,6 +663,7 @@ func init() {
 			}
 			out.Spec.PodCIDR = in.PodCIDR
 			out.Spec.ExternalID = in.ExternalID
+			out.Spec.Unschedulable = in.Unschedulable
 			return s.Convert(&in.NodeResources.Capacity, &out.Spec.Capacity, 0)
 		},
 

pkg/api/v1beta2/types.go

@@ -690,6 +690,8 @@ const (
 	NodeReachable NodeConditionKind = "Reachable"
 	// NodeReady means the node returns StatusOK for HTTP health check.
 	NodeReady NodeConditionKind = "Ready"
+	// NodeSchedulable means the node is ready to accept new pods.
+	NodeSchedulable NodeConditionKind = "Schedulable"
 )
 
 // Described the conditions of a running node.
@@ -750,6 +752,8 @@ type Minion struct {
 	NodeResources NodeResources `json:"resources,omitempty" description:"characterization of node resources"`
 	// Pod IP range assigned to the node
 	PodCIDR string `json:"podCIDR,omitempty" description:"IP range assigned to the node"`
+	// Unschedulable controls node schedulability of new pods. By default node is schedulable.
+	Unschedulable bool `json:"unschedulable,omitempty" description:"disable pod scheduling on the node"`
 	// Status describes the current status of a node
 	Status NodeStatus `json:"status,omitempty" description:"current status of node"`
 	// Labels for the node

pkg/api/v1beta3/types.go

@@ -813,13 +813,15 @@ type EndpointsList struct {
 
 // NodeSpec describes the attributes that a node is created with.
 type NodeSpec struct {
-	// Capacity represents the available resources of a node
+	// Capacity represents the available resources of a node.
 	// see https://github.com/GoogleCloudPlatform/kubernetes/blob/master/docs/resources.md for more details.
 	Capacity ResourceList `json:"capacity,omitempty" description:"compute resource capacity of the node; https://github.com/GoogleCloudPlatform/kubernetes/blob/master/docs/resources.md"`
 	// PodCIDR represents the pod IP range assigned to the node
 	PodCIDR string `json:"podCIDR,omitempty" description:"pod IP range assigned to the node"`
 	// External ID of the node assigned by some machine database (e.g. a cloud provider)
 	ExternalID string `json:"externalID,omitempty" description:"external ID assigned to the node by some machine database (e.g. a cloud provider)"`
+	// Unschedulable controls node schedulability of new pods. By default node is schedulable.
+	Unschedulable bool `json:"unschedulable,omitempty" description:"disable pod scheduling on the node"`
 }
 
 // NodeSystemInfo is a set of ids/uuids to uniquely identify the node.
@@ -873,6 +875,8 @@ const (
 	NodeReachable NodeConditionType = "Reachable"
 	// NodeReady means the node returns StatusOK for HTTP health check.
 	NodeReady NodeConditionType = "Ready"
+	// NodeSchedulable means the node is ready to accept new pods.
+	NodeSchedulable NodeConditionType = "Schedulable"
 )
 
 type NodeCondition struct {

pkg/api/validation/validation.go

@@ -862,6 +862,8 @@ func ValidateMinionUpdate(oldMinion *api.Node, minion *api.Node) errs.Validation
 	oldMinion.ObjectMeta = minion.ObjectMeta
 	// Allow users to update capacity
 	oldMinion.Spec.Capacity = minion.Spec.Capacity
+	// Allow users to unschedule node
+	oldMinion.Spec.Unschedulable = minion.Spec.Unschedulable
 	// Clear status
 	oldMinion.Status = minion.Status
 

pkg/api/validation/validation_test.go

@@ -2106,6 +2106,21 @@ func TestValidateMinionUpdate(t *testing.T) {
 				Labels: map[string]string{"Foo": "baz"},
 			},
 		}, true},
+		{api.Node{
+			ObjectMeta: api.ObjectMeta{
+				Name: "foo",
+			},
+			Spec: api.NodeSpec{
+				Unschedulable: false,
+			},
+		}, api.Node{
+			ObjectMeta: api.ObjectMeta{
+				Name: "foo",
+			},
+			Spec: api.NodeSpec{
+				Unschedulable: true,
+			},
+		}, true},
 	}
 	for i, test := range tests {
 		errs := ValidateMinionUpdate(&test.oldMinion, &test.minion)

pkg/client/client_test.go

@@ -749,6 +749,7 @@ func TestCreateMinion(t *testing.T) {
 				api.ResourceCPU:    resource.MustParse("1000m"),
 				api.ResourceMemory: resource.MustParse("1Mi"),
 			},
+			Unschedulable: false,
 		},
 	}
 	c := &testClient{
@@ -782,6 +783,7 @@ func TestUpdateMinion(t *testing.T) {
 				api.ResourceCPU:    resource.MustParse("1000m"),
 				api.ResourceMemory: resource.MustParse("1Mi"),
 			},
+			Unschedulable: true,
 		},
 	}
 	c := &testClient{

pkg/cloudprovider/controller/nodecontroller.go

@@ -301,7 +301,7 @@ func (s *NodeController) PopulateAddresses(nodes *api.NodeList) (*api.NodeList,
 	return nodes, nil
 }
 
-// UpdateNodesStatus performs health checking for given list of nodes.
+// UpdateNodesStatus performs various condition checks for given list of nodes.
 func (s *NodeController) UpdateNodesStatus(nodes *api.NodeList) *api.NodeList {
 	var wg sync.WaitGroup
 	wg.Add(len(nodes.Items))
@@ -330,21 +330,14 @@ func (s *NodeController) updateNodeInfo(node *api.Node) error {
 	return nil
 }
 
-// DoCheck performs health checking for given node.
+// DoCheck performs various condition checks for given node.
 func (s *NodeController) DoCheck(node *api.Node) []api.NodeCondition {
 	var conditions []api.NodeCondition
 
 	// Check Condition: NodeReady. TODO: More node conditions.
 	oldReadyCondition := s.getCondition(node, api.NodeReady)
 	newReadyCondition := s.checkNodeReady(node)
-	if oldReadyCondition != nil && oldReadyCondition.Status == newReadyCondition.Status {
+	s.updateLastTransitionTime(oldReadyCondition, newReadyCondition)
-		// If node status doesn't change, transition time is same as last time.
-		newReadyCondition.LastTransitionTime = oldReadyCondition.LastTransitionTime
-	} else {
-		// Set transition time to Now() if node status changes or `oldReadyCondition` is nil, which
-		// happens only when the node is checked for the first time.
-		newReadyCondition.LastTransitionTime = util.Now()
-	}
 
 	if newReadyCondition.Status != api.ConditionFull {
 		// Node is not ready for this probe, we need to check if pods need to be deleted.
@@ -355,12 +348,48 @@ func (s *NodeController) DoCheck(node *api.Node) []api.NodeCondition {
 			s.deletePods(node.Name)
 		}
 	}
-
 	conditions = append(conditions, *newReadyCondition)
 
+	// Check Condition: NodeSchedulable
+	oldSchedulableCondition := s.getCondition(node, api.NodeSchedulable)
+	newSchedulableCondition := s.checkNodeSchedulable(node)
+	s.updateLastTransitionTime(oldSchedulableCondition, newSchedulableCondition)
+	conditions = append(conditions, *newSchedulableCondition)
+
 	return conditions
 }
 
+// updateLastTransitionTime updates LastTransitionTime for the newCondition based on oldCondition.
+func (s *NodeController) updateLastTransitionTime(oldCondition, newCondition *api.NodeCondition) {
+	if oldCondition != nil && oldCondition.Status == newCondition.Status {
+		// If node status doesn't change, transition time is same as last time.
+		newCondition.LastTransitionTime = oldCondition.LastTransitionTime
+	} else {
+		// Set transition time to Now() if node status changes or `oldCondition` is nil, which
+		// happens only when the node is checked for the first time.
+		newCondition.LastTransitionTime = util.Now()
+	}
+}
+
+// checkNodeSchedulable checks node schedulable condition, without transition timestamp set.
+func (s *NodeController) checkNodeSchedulable(node *api.Node) *api.NodeCondition {
+	if node.Spec.Unschedulable {
+		return &api.NodeCondition{
+			Type:          api.NodeSchedulable,
+			Status:        api.ConditionNone,
+			Reason:        "User marked unschedulable during node create/update",
+			LastProbeTime: util.Now(),
+		}
+	} else {
+		return &api.NodeCondition{
+			Type:          api.NodeSchedulable,
+			Status:        api.ConditionFull,
+			Reason:        "Node is schedulable by default",
+			LastProbeTime: util.Now(),
+		}
+	}
+}
+
 // checkNodeReady checks raw node ready condition, without transition timestamp set.
 func (s *NodeController) checkNodeReady(node *api.Node) *api.NodeCondition {
 	switch status, err := s.kubeletClient.HealthCheck(node.Name); {

pkg/cloudprovider/controller/nodecontroller_test.go

@@ -550,13 +550,15 @@ func TestSyncCloudDeletePods(t *testing.T) {
 	}
 }
 
-func TestHealthCheckNode(t *testing.T) {
+func TestNodeConditionsCheck(t *testing.T) {
 	table := []struct {
 		node               *api.Node
 		fakeKubeletClient  *FakeKubeletClient
 		expectedConditions []api.NodeCondition
 	}{
 		{
+			// Node with default spec and kubelet /healthz probe returns success.
+			// Expected node condition to be ready and marked schedulable.
 			node: newNode("node0"),
 			fakeKubeletClient: &FakeKubeletClient{
 				Status: probe.Success,
@@ -568,10 +570,17 @@ func TestHealthCheckNode(t *testing.T) {
 					Status: api.ConditionFull,
 					Reason: "Node health check succeeded: kubelet /healthz endpoint returns ok",
 				},
+				{
+					Type:   api.NodeSchedulable,
+					Status: api.ConditionFull,
+					Reason: "Node is schedulable by default",
+				},
 			},
 		},
 		{
-			node: newNode("node0"),
+			// User specified node as schedulable and kubelet /healthz probe returns failure with no error.
+			// Expected node condition to be not ready and marked schedulable.
+			node: &api.Node{ObjectMeta: api.ObjectMeta{Name: "node0"}, Spec: api.NodeSpec{Unschedulable: false}},
 			fakeKubeletClient: &FakeKubeletClient{
 				Status: probe.Failure,
 				Err:    nil,
@@ -582,10 +591,17 @@ func TestHealthCheckNode(t *testing.T) {
 					Status: api.ConditionNone,
 					Reason: "Node health check failed: kubelet /healthz endpoint returns not ok",
 				},
+				{
+					Type:   api.NodeSchedulable,
+					Status: api.ConditionFull,
+					Reason: "Node is schedulable by default",
+				},
 			},
 		},
 		{
-			node: newNode("node0"),
+			// User specified node as unschedulable and kubelet /healthz probe returns failure with some error.
+			// Expected node condition to be not ready and marked unschedulable.
+			node: &api.Node{ObjectMeta: api.ObjectMeta{Name: "node0"}, Spec: api.NodeSpec{Unschedulable: true}},
 			fakeKubeletClient: &FakeKubeletClient{
 				Status: probe.Failure,
 				Err:    errors.New("Error"),
@@ -596,6 +612,11 @@ func TestHealthCheckNode(t *testing.T) {
 					Status: api.ConditionUnknown,
 					Reason: "Node health check error: Error",
 				},
+				{
+					Type:   api.NodeSchedulable,
+					Status: api.ConditionNone,
+					Reason: "User marked unschedulable during node create/update",
+				},
 			},
 		},
 	}
@@ -663,11 +684,13 @@ func TestSyncNodeStatusTransitionTime(t *testing.T) {
 		expectedTransitionTimeChange bool
 	}{
 		{
-			// Existing node is healthy, current porbe is healthy too.
+			// Existing node is healthy, current probe is healthy too.
+			// Existing node is schedulable, again explicitly mark node as schedulable.
 			fakeNodeHandler: &FakeNodeHandler{
 				Existing: []*api.Node{
 					{
 						ObjectMeta: api.ObjectMeta{Name: "node0"},
+						Spec:       api.NodeSpec{Unschedulable: false},
 						Status: api.NodeStatus{
 							Conditions: []api.NodeCondition{
 								{
@@ -676,6 +699,12 @@ func TestSyncNodeStatusTransitionTime(t *testing.T) {
 									Reason:             "Node health check succeeded: kubelet /healthz endpoint returns ok",
 									LastTransitionTime: util.Date(2012, 1, 1, 0, 0, 0, 0, time.UTC),
 								},
+								{
+									Type:               api.NodeSchedulable,
+									Status:             api.ConditionFull,
+									Reason:             "Node is schedulable by default",
+									LastTransitionTime: util.Date(2012, 1, 1, 0, 0, 0, 0, time.UTC),
+								},
 							},
 						},
 					},
@@ -689,11 +718,13 @@ func TestSyncNodeStatusTransitionTime(t *testing.T) {
 			expectedTransitionTimeChange: false,
 		},
 		{
-			// Existing node is healthy, current porbe is unhealthy.
+			// Existing node is healthy, current probe is unhealthy.
+			// Existing node is schedulable, mark node as unschedulable.
 			fakeNodeHandler: &FakeNodeHandler{
 				Existing: []*api.Node{
 					{
 						ObjectMeta: api.ObjectMeta{Name: "node0"},
+						Spec:       api.NodeSpec{Unschedulable: true},
 						Status: api.NodeStatus{
 							Conditions: []api.NodeCondition{
 								{
@@ -702,6 +733,12 @@ func TestSyncNodeStatusTransitionTime(t *testing.T) {
 									Reason:             "Node health check succeeded: kubelet /healthz endpoint returns ok",
 									LastTransitionTime: util.Date(2012, 1, 1, 0, 0, 0, 0, time.UTC),
 								},
+								{
+									Type:               api.NodeSchedulable,
+									Status:             api.ConditionFull,
+									Reason:             "Node is schedulable by default",
+									LastTransitionTime: util.Date(2012, 1, 1, 0, 0, 0, 0, time.UTC),
+								},
 							},
 						},
 					},
@@ -865,7 +902,7 @@ func TestSyncNodeStatusDeletePods(t *testing.T) {
 		expectedActions      []client.FakeAction
 	}{
 		{
-			// Existing node is healthy, current porbe is healthy too.
+			// Existing node is healthy, current probe is healthy too.
 			fakeNodeHandler: &FakeNodeHandler{
 				Existing: []*api.Node{
 					{
@@ -894,7 +931,7 @@ func TestSyncNodeStatusDeletePods(t *testing.T) {
 			expectedActions:      nil,
 		},
 		{
-			// Existing node is healthy, current porbe is unhealthy, i.e. node just becomes unhealthy.
+			// Existing node is healthy, current probe is unhealthy, i.e. node just becomes unhealthy.
 			// Do not delete pods.
 			fakeNodeHandler: &FakeNodeHandler{
 				Existing: []*api.Node{
@@ -924,7 +961,7 @@ func TestSyncNodeStatusDeletePods(t *testing.T) {
 			expectedActions:      nil,
 		},
 		{
-			// Existing node unhealthy, current porbe is unhealthy. Node is still within grace peroid.
+			// Existing node unhealthy, current probe is unhealthy. Node is still within grace peroid.
 			fakeNodeHandler: &FakeNodeHandler{
 				Existing: []*api.Node{
 					{
@@ -956,7 +993,7 @@ func TestSyncNodeStatusDeletePods(t *testing.T) {
 			expectedActions:      nil,
 		},
 		{
-			// Existing node unhealthy, current porbe is unhealthy. Node exceeds grace peroid.
+			// Existing node unhealthy, current probe is unhealthy. Node exceeds grace peroid.
 			fakeNodeHandler: &FakeNodeHandler{
 				Existing: []*api.Node{
 					{
@@ -1036,6 +1073,11 @@ func TestSyncNodeStatus(t *testing.T) {
 								Status: api.ConditionFull,
 								Reason: "Node health check succeeded: kubelet /healthz endpoint returns ok",
 							},
+							{
+								Type:   api.NodeSchedulable,
+								Status: api.ConditionFull,
+								Reason: "Node is schedulable by default",
+							},
 						},
 						Addresses: []api.NodeAddress{
 							{Type: api.NodeLegacyHostIP, Address: "1.2.3.4"},
@@ -1051,6 +1093,11 @@ func TestSyncNodeStatus(t *testing.T) {
 								Status: api.ConditionFull,
 								Reason: "Node health check succeeded: kubelet /healthz endpoint returns ok",
 							},
+							{
+								Type:   api.NodeSchedulable,
+								Status: api.ConditionFull,
+								Reason: "Node is schedulable by default",
+							},
 						},
 						Addresses: []api.NodeAddress{
 							{Type: api.NodeLegacyHostIP, Address: "1.2.3.4"},

pkg/kubectl/resource_printer.go

@@ -432,7 +432,7 @@ func printSecretList(list *api.SecretList, w io.Writer) error {
 
 func printNode(node *api.Node, w io.Writer) error {
 	conditionMap := make(map[api.NodeConditionType]*api.NodeCondition)
-	NodeAllConditions := []api.NodeConditionType{api.NodeReady, api.NodeReachable}
+	NodeAllConditions := []api.NodeConditionType{api.NodeSchedulable, api.NodeReady, api.NodeReachable}
 	for i := range node.Status.Conditions {
 		cond := node.Status.Conditions[i]
 		conditionMap[cond.Type] = &cond

pkg/kubectl/resource_printer_test.go

@@ -567,6 +567,26 @@ func TestPrintMinionStatus(t *testing.T) {
 			},
 			status: "Unknown",
 		},
+		{
+			minion: api.Node{
+				ObjectMeta: api.ObjectMeta{Name: "foo7"},
+				Status: api.NodeStatus{Conditions: []api.NodeCondition{
+					{Type: api.NodeSchedulable, Status: api.ConditionFull},
+					{Type: api.NodeReady, Status: api.ConditionFull},
+					{Type: api.NodeReachable, Status: api.ConditionFull}}},
+			},
+			status: "Schedulable,Ready,Reachable",
+		},
+		{
+			minion: api.Node{
+				ObjectMeta: api.ObjectMeta{Name: "foo8"},
+				Status: api.NodeStatus{Conditions: []api.NodeCondition{
+					{Type: api.NodeSchedulable, Status: api.ConditionNone},
+					{Type: api.NodeReady, Status: api.ConditionNone},
+					{Type: api.NodeReachable, Status: api.ConditionFull}}},
+			},
+			status: "NotSchedulable,NotReady,Reachable",
+		},
 	}
 
 	for _, test := range table {

pkg/registry/minion/rest.go

@@ -46,7 +46,6 @@ func NewREST(m Registry) *REST {
 }
 
 var ErrDoesNotExist = errors.New("The requested resource does not exist.")
-var ErrNotHealty = errors.New("The requested minion is not healthy.")
 
 // Create satisfies the RESTStorage interface.
 func (rs *REST) Create(ctx api.Context, obj runtime.Object) (runtime.Object, error) {

plugin/pkg/scheduler/factory/factory.go

@@ -207,6 +207,11 @@ func (factory *ConfigFactory) pollMinions() (cache.Enumerator, error) {
 			cond := node.Status.Conditions[i]
 			conditionMap[cond.Type] = &cond
 		}
+		if condition, ok := conditionMap[api.NodeSchedulable]; ok {
+			if condition.Status != api.ConditionFull {
+				continue
+			}
+		}
 		if condition, ok := conditionMap[api.NodeReady]; ok {
 			if condition.Status == api.ConditionFull {
 				nodes.Items = append(nodes.Items, node)

plugin/pkg/scheduler/factory/factory_test.go

@@ -156,7 +156,15 @@ func TestPollMinions(t *testing.T) {
 					},
 				},
 				{
-					ObjectMeta: api.ObjectMeta{Name: "baz"},
+					ObjectMeta: api.ObjectMeta{Name: "fiz"},
+					Status: api.NodeStatus{
+						Conditions: []api.NodeCondition{
+							{Type: api.NodeSchedulable, Status: api.ConditionFull},
+						},
+					},
+				},
+				{
+					ObjectMeta: api.ObjectMeta{Name: "biz"},
 					Status: api.NodeStatus{
 						Conditions: []api.NodeCondition{
 							{Type: api.NodeReady, Status: api.ConditionFull},
@@ -173,8 +181,47 @@ func TestPollMinions(t *testing.T) {
 						},
 					},
 				},
+				{
+					ObjectMeta: api.ObjectMeta{Name: "fuz"},
+					Status: api.NodeStatus{
+						Conditions: []api.NodeCondition{
+							{Type: api.NodeSchedulable, Status: api.ConditionFull},
+							{Type: api.NodeReady, Status: api.ConditionFull},
+							{Type: api.NodeReachable, Status: api.ConditionFull},
 						},
-			expectedCount: 4,
+					},
+				},
+				{
+					ObjectMeta: api.ObjectMeta{Name: "buz"},
+					Status: api.NodeStatus{
+						Conditions: []api.NodeCondition{
+							{Type: api.NodeSchedulable, Status: api.ConditionNone},
+							{Type: api.NodeReady, Status: api.ConditionFull},
+							{Type: api.NodeReachable, Status: api.ConditionFull},
+						},
+					},
+				},
+				{
+					ObjectMeta: api.ObjectMeta{Name: "foobar"},
+					Status: api.NodeStatus{
+						Conditions: []api.NodeCondition{
+							{Type: api.NodeSchedulable, Status: api.ConditionFull},
+							{Type: api.NodeReady, Status: api.ConditionNone},
+							{Type: api.NodeReachable, Status: api.ConditionFull},
+						},
+					},
+				},
+				{
+					ObjectMeta: api.ObjectMeta{Name: "fizbiz"},
+					Status: api.NodeStatus{
+						Conditions: []api.NodeCondition{
+							{Type: api.NodeSchedulable, Status: api.ConditionFull},
+							{Type: api.NodeReachable, Status: api.ConditionNone},
+						},
+					},
+				},
+			},
+			expectedCount: 6,
 		},
 		{
 			minions: []api.Node{
@@ -197,6 +244,27 @@ func TestPollMinions(t *testing.T) {
 			},
 			expectedCount: 1,
 		},
+		{
+			minions: []api.Node{
+				{
+					ObjectMeta: api.ObjectMeta{Name: "foo"},
+					Status: api.NodeStatus{
+						Conditions: []api.NodeCondition{
+							{Type: api.NodeSchedulable, Status: api.ConditionFull},
+						},
+					},
+				},
+				{
+					ObjectMeta: api.ObjectMeta{Name: "bar"},
+					Status: api.NodeStatus{
+						Conditions: []api.NodeCondition{
+							{Type: api.NodeSchedulable, Status: api.ConditionNone},
+						},
+					},
+				},
+			},
+			expectedCount: 1,
+		},
 		{
 			minions: []api.Node{
 				{