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Merge pull request #92752 from chendave/skip_preemption

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Cut off the cost to run filter plugins when no victim pods are found
This commit is contained in:
Kubernetes Prow Robot 2020-07-09 09:10:10 -07:00 committed by GitHub
commit 3a5e7ea986
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2 changed files with 20 additions and 45 deletions
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13
pkg/scheduler/framework/plugins/defaultpreemption/default_preemption.go
View File

@ -315,13 +315,6 @@ func pickOneNodeForPreemption(nodesToVictims map[string]*extenderv1.Victims) str
var minNodes1 []string
lenNodes1 := 0
for node, victims := range nodesToVictims {
if len(victims.Pods) == 0 {
// We found a node that doesn't need any preemption. Return it!
// This should happen rarely when one or more pods are terminated between
// the time that scheduler tries to schedule the pod and the time that
// preemption logic tries to find nodes for preemption.
return node
}
numPDBViolatingPods := victims.NumPDBViolations
if numPDBViolatingPods < minNumPDBViolatingPods {
minNumPDBViolatingPods = numPDBViolatingPods
@ -488,6 +481,12 @@ func selectVictimsOnNode(
}
}
}
// No potential victims are found, and so we don't need to evaluate the node again since its state didn't change.
if len(potentialVictims) == 0 {
return nil, 0, false
}
// If the new pod does not fit after removing all the lower priority pods,
// we are almost done and this node is not suitable for preemption. The only
// condition that we could check is if the "pod" is failing to schedule due to

52
pkg/scheduler/framework/plugins/defaultpreemption/default_preemption_test.go
View File

@ -323,7 +323,7 @@ func TestSelectNodesForPreemption(t *testing.T) {
expectedNumFilterCalled: 4,
},
{
name: "a pod that would fit on the machines, but other pods running are higher priority",
name: "a pod that would fit on the machines, but other pods running are higher priority, no preemption would happen",
registerPlugins: []st.RegisterPluginFunc{
st.RegisterPluginAsExtensions(noderesources.FitName, noderesources.NewFit, "Filter", "PreFilter"),
},
@ -334,7 +334,7 @@ func TestSelectNodesForPreemption(t *testing.T) {
st.MakePod().Name("p2").UID("p2").Node("node2").Priority(midPriority).Req(largeRes).Obj(),
},
expected: map[string]*extenderv1.Victims{},
expectedNumFilterCalled: 2,
expectedNumFilterCalled: 0,
},
{
name: "medium priority pod is preempted, but lower priority one stays as it is small",
@ -380,7 +380,7 @@ func TestSelectNodesForPreemption(t *testing.T) {
},
},
},
expectedNumFilterCalled: 5,
expectedNumFilterCalled: 4,
},
{
name: "mixed priority pods are preempted, pick later StartTime one when priorities are equal",
@ -404,7 +404,7 @@ func TestSelectNodesForPreemption(t *testing.T) {
},
},
},
expectedNumFilterCalled: 5,
expectedNumFilterCalled: 4, // no preemption would happen on node2 and no filter call is counted.
},
{
name: "pod with anti-affinity is preempted",
@ -428,9 +428,8 @@ func TestSelectNodesForPreemption(t *testing.T) {
PodAntiAffinityExists("foo", "hostname", st.PodAntiAffinityWithRequiredReq).Obj(),
},
},
"node2": {},
},
expectedNumFilterCalled: 4,
expectedNumFilterCalled: 3, // no preemption would happen on node2 and no filter call is counted.
},
{
name: "preemption to resolve pod topology spread filter failure",
@ -457,7 +456,7 @@ func TestSelectNodesForPreemption(t *testing.T) {
Pods: []*v1.Pod{st.MakePod().Name("pod-b1").UID("pod-b1").Node("node-b").Label("foo", "").Priority(lowPriority).Obj()},
},
},
expectedNumFilterCalled: 6,
expectedNumFilterCalled: 5, // node-a (3), node-b (2), node-x (0)
},
{
name: "get Unschedulable in the preemption phase when the filter plugins filtering the nodes",
@ -696,17 +695,6 @@ func TestPickOneNodeForPreemption(t *testing.T) {
},
expected: []string{"node1", "node2"},
},
{
name: "a pod that fits on a machine with no preemption",
registerPlugin: st.RegisterPluginAsExtensions(noderesources.FitName, noderesources.NewFit, "Filter", "PreFilter"),
nodeNames: []string{"node1", "node2", "node3"},
pod: st.MakePod().Name("p").UID("p").Priority(highPriority).Req(largeRes).Obj(),
pods: []*v1.Pod{
st.MakePod().Name("p1").UID("p1").Node("node1").Priority(midPriority).Req(largeRes).StartTime(epochTime).Obj(),
st.MakePod().Name("p2").UID("p2").Node("node2").Priority(midPriority).Req(largeRes).StartTime(epochTime).Obj(),
},
expected: []string{"node3"},
},
{
name: "machine with min highest priority pod is picked",
registerPlugin: st.RegisterPluginAsExtensions(noderesources.FitName, noderesources.NewFit, "Filter", "PreFilter"),
@ -1088,19 +1076,6 @@ func TestPreempt(t *testing.T) {
expectedNode: "node1",
expectedPods: []string{"p1.1", "p1.2"},
},
{
name: "One node doesn't need any preemption",
pod: st.MakePod().Name("p").UID("p").Priority(highPriority).Req(veryLargeRes).PreemptionPolicy(v1.PreemptLowerPriority).Obj(),
pods: []*v1.Pod{
st.MakePod().Name("p1.1").UID("p1.1").Node("node1").Priority(lowPriority).Req(smallRes).Obj(),
st.MakePod().Name("p1.2").UID("p1.2").Node("node1").Priority(lowPriority).Req(smallRes).Obj(),
st.MakePod().Name("p2.1").UID("p2.1").Node("node2").Priority(highPriority).Req(largeRes).Obj(),
},
nodeNames: []string{"node1", "node2", "node3"},
registerPlugin: st.RegisterPluginAsExtensions(noderesources.FitName, noderesources.NewFit, "Filter", "PreFilter"),
expectedNode: "node3",
expectedPods: []string{},
},
{
name: "preemption for topology spread constraints",
pod: st.MakePod().Name("p").UID("p").Label("foo", "").Priority(highPriority).
@ -1170,21 +1145,22 @@ func TestPreempt(t *testing.T) {
expectedPods: []string{"p1.1", "p1.2"},
},
{
name: "One scheduler extender allows only machine1, but it is not interested in given pod, otherwise node1 would have been chosen",
name: "One scheduler extender allows only machine1, but it is not interested in given pod, otherwise machine1 would have been chosen",
pod: st.MakePod().Name("p").UID("p").Priority(highPriority).Req(veryLargeRes).PreemptionPolicy(v1.PreemptLowerPriority).Obj(),
pods: []*v1.Pod{
st.MakePod().Name("p1.1").UID("p1.1").Node("node1").Priority(midPriority).Req(smallRes).Obj(),
st.MakePod().Name("p1.2").UID("p1.2").Node("node1").Priority(lowPriority).Req(smallRes).Obj(),
st.MakePod().Name("p2.1").UID("p2.1").Node("node2").Priority(midPriority).Req(largeRes).Obj(),
st.MakePod().Name("p1.1").UID("p1.1").Node("machine1").Priority(midPriority).Req(smallRes).Obj(),
st.MakePod().Name("p1.2").UID("p1.2").Node("machine1").Priority(lowPriority).Req(smallRes).Obj(),
st.MakePod().Name("p2.1").UID("p2.1").Node("machine2").Priority(midPriority).Req(largeRes).Obj(),
},
nodeNames: []string{"node1", "node2", "node3"},
nodeNames: []string{"machine1", "machine2"},
extenders: []*st.FakeExtender{
{Predicates: []st.FitPredicate{st.Machine1PredicateExtender}, UnInterested: true},
{Predicates: []st.FitPredicate{st.TruePredicateExtender}},
},
registerPlugin: st.RegisterPluginAsExtensions(noderesources.FitName, noderesources.NewFit, "Filter", "PreFilter"),
expectedNode: "node3",
expectedPods: []string{},
// sum of priorities of all victims on machine1 is larger than machine2, machine2 is chosen.
expectedNode: "machine2",
expectedPods: []string{"p2.1"},
},
{
name: "no preempting in pod",