Do not schedule pod to the node under PID pressure.

Signed-off-by: Da K. Ma <klaus1982.cn@gmail.com>

pkg/scheduler/algorithmprovider/defaults/compatibility_test.go

@@ -480,7 +480,6 @@ func TestCompatibility_v1_Scheduler(t *testing.T) {
 			{"name": "CheckVolumeBinding"},
 			{"name": "TestServiceAffinity", "argument": {"serviceAffinity" : {"labels" : ["region"]}}},
 			{"name": "TestLabelsPresence",  "argument": {"labelsPresence"  : {"labels" : ["foo"], "presence":true}}}
-
 		  ],"priorities": [
 			{"name": "EqualPriority",   "weight": 2},
 			{"name": "ImageLocalityPriority",   "weight": 2},
@@ -529,6 +528,81 @@ func TestCompatibility_v1_Scheduler(t *testing.T) {
 				},
 			},
 		},
+		// Do not change this JSON after the corresponding release has been tagged.
+		// A failure indicates backwards compatibility with the specified release was broken.
+		"1.10": {
+			JSON: `{
+		  "kind": "Policy",
+		  "apiVersion": "v1",
+		  "predicates": [
+			{"name": "MatchNodeSelector"},
+			{"name": "PodFitsResources"},
+			{"name": "PodFitsHostPorts"},
+			{"name": "HostName"},
+			{"name": "NoDiskConflict"},
+			{"name": "NoVolumeZoneConflict"},
+			{"name": "PodToleratesNodeTaints"},
+			{"name": "CheckNodeMemoryPressure"},
+			{"name": "CheckNodeDiskPressure"},
+			{"name": "CheckNodePIDPressure"},
+			{"name": "CheckNodeCondition"},
+			{"name": "MaxEBSVolumeCount"},
+			{"name": "MaxGCEPDVolumeCount"},
+			{"name": "MaxAzureDiskVolumeCount"},
+			{"name": "MatchInterPodAffinity"},
+			{"name": "GeneralPredicates"},
+			{"name": "CheckVolumeBinding"},
+			{"name": "TestServiceAffinity", "argument": {"serviceAffinity" : {"labels" : ["region"]}}},
+			{"name": "TestLabelsPresence",  "argument": {"labelsPresence"  : {"labels" : ["foo"], "presence":true}}}
+		  ],"priorities": [
+			{"name": "EqualPriority",   "weight": 2},
+			{"name": "ImageLocalityPriority",   "weight": 2},
+			{"name": "LeastRequestedPriority",   "weight": 2},
+			{"name": "BalancedResourceAllocation",   "weight": 2},
+			{"name": "SelectorSpreadPriority",   "weight": 2},
+			{"name": "NodePreferAvoidPodsPriority",   "weight": 2},
+			{"name": "NodeAffinityPriority",   "weight": 2},
+			{"name": "TaintTolerationPriority",   "weight": 2},
+			{"name": "InterPodAffinityPriority",   "weight": 2},
+			{"name": "MostRequestedPriority",   "weight": 2}
+		  ]
+		}`,
+			ExpectedPolicy: schedulerapi.Policy{
+				Predicates: []schedulerapi.PredicatePolicy{
+					{Name: "MatchNodeSelector"},
+					{Name: "PodFitsResources"},
+					{Name: "PodFitsHostPorts"},
+					{Name: "HostName"},
+					{Name: "NoDiskConflict"},
+					{Name: "NoVolumeZoneConflict"},
+					{Name: "PodToleratesNodeTaints"},
+					{Name: "CheckNodeMemoryPressure"},
+					{Name: "CheckNodeDiskPressure"},
+					{Name: "CheckNodePIDPressure"},
+					{Name: "CheckNodeCondition"},
+					{Name: "MaxEBSVolumeCount"},
+					{Name: "MaxGCEPDVolumeCount"},
+					{Name: "MaxAzureDiskVolumeCount"},
+					{Name: "MatchInterPodAffinity"},
+					{Name: "GeneralPredicates"},
+					{Name: "CheckVolumeBinding"},
+					{Name: "TestServiceAffinity", Argument: &schedulerapi.PredicateArgument{ServiceAffinity: &schedulerapi.ServiceAffinity{Labels: []string{"region"}}}},
+					{Name: "TestLabelsPresence", Argument: &schedulerapi.PredicateArgument{LabelsPresence: &schedulerapi.LabelsPresence{Labels: []string{"foo"}, Presence: true}}},
+				},
+				Priorities: []schedulerapi.PriorityPolicy{
+					{Name: "EqualPriority", Weight: 2},
+					{Name: "ImageLocalityPriority", Weight: 2},
+					{Name: "LeastRequestedPriority", Weight: 2},
+					{Name: "BalancedResourceAllocation", Weight: 2},
+					{Name: "SelectorSpreadPriority", Weight: 2},
+					{Name: "NodePreferAvoidPodsPriority", Weight: 2},
+					{Name: "NodeAffinityPriority", Weight: 2},
+					{Name: "TaintTolerationPriority", Weight: 2},
+					{Name: "InterPodAffinityPriority", Weight: 2},
+					{Name: "MostRequestedPriority", Weight: 2},
+				},
+			},
+		},
 	}
 
 	registeredPredicates := sets.NewString(factory.ListRegisteredFitPredicates()...)

pkg/scheduler/algorithmprovider/defaults/defaults.go

@@ -17,6 +17,8 @@ limitations under the License.
 package defaults
 
 import (
+	"github.com/golang/glog"
+
 	"k8s.io/apimachinery/pkg/util/sets"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 
@@ -26,8 +28,6 @@ import (
 	"k8s.io/kubernetes/pkg/scheduler/algorithm/priorities"
 	"k8s.io/kubernetes/pkg/scheduler/core"
 	"k8s.io/kubernetes/pkg/scheduler/factory"
-
-	"github.com/golang/glog"
 )
 
 const (
@@ -160,6 +160,9 @@ func defaultPredicates() sets.String {
 		// Fit is determined by node disk pressure condition.
 		factory.RegisterFitPredicate(predicates.CheckNodeDiskPressurePred, predicates.CheckNodeDiskPressurePredicate),
 
+		// Fit is determined by node pid pressure condition.
+		factory.RegisterFitPredicate(predicates.CheckNodePIDPressurePred, predicates.CheckNodePIDPressurePredicate),
+
 		// Fit is determined by node conditions: not ready, network unavailable or out of disk.
 		factory.RegisterMandatoryFitPredicate(predicates.CheckNodeConditionPred, predicates.CheckNodeConditionPredicate),
 
@@ -179,10 +182,12 @@ func defaultPredicates() sets.String {
 // ApplyFeatureGates applies algorithm by feature gates.
 func ApplyFeatureGates() {
 	if utilfeature.DefaultFeatureGate.Enabled(features.TaintNodesByCondition) {
-		// Remove "CheckNodeCondition", "CheckNodeMemoryPressure" and "CheckNodeDiskPressure" predicates
+		// Remove "CheckNodeCondition", "CheckNodeMemoryPressure", "CheckNodePIDPressurePred"
+		// and "CheckNodeDiskPressure" predicates
 		factory.RemoveFitPredicate(predicates.CheckNodeConditionPred)
 		factory.RemoveFitPredicate(predicates.CheckNodeMemoryPressurePred)
 		factory.RemoveFitPredicate(predicates.CheckNodeDiskPressurePred)
+		factory.RemoveFitPredicate(predicates.CheckNodePIDPressurePred)
 		// Remove key "CheckNodeCondition", "CheckNodeMemoryPressure" and "CheckNodeDiskPressure"
 		// from ALL algorithm provider
 		// The key will be removed from all providers which in algorithmProviderMap[]
@@ -190,6 +195,7 @@ func ApplyFeatureGates() {
 		factory.RemovePredicateKeyFromAlgorithmProviderMap(predicates.CheckNodeConditionPred)
 		factory.RemovePredicateKeyFromAlgorithmProviderMap(predicates.CheckNodeMemoryPressurePred)
 		factory.RemovePredicateKeyFromAlgorithmProviderMap(predicates.CheckNodeDiskPressurePred)
+		factory.RemovePredicateKeyFromAlgorithmProviderMap(predicates.CheckNodePIDPressurePred)
 
 		// Fit is determined based on whether a pod can tolerate all of the node's taints
 		factory.RegisterMandatoryFitPredicate(predicates.PodToleratesNodeTaintsPred, predicates.PodToleratesNodeTaints)

pkg/scheduler/algorithmprovider/defaults/defaults_test.go

@@ -76,6 +76,7 @@ func TestDefaultPredicates(t *testing.T) {
 		"GeneralPredicates",
 		"CheckNodeMemoryPressure",
 		"CheckNodeDiskPressure",
+		"CheckNodePIDPressure",
 		"CheckNodeCondition",
 		"PodToleratesNodeTaints",
 		predicates.CheckVolumeBindingPred,