(TopologySpread) Evict pods with selectors that match multiple nodes

kubernetes-sigs · Mar 11, 2021 · 4da1862 · 4da1862
1 parent 0a11b5a
commit 4da1862
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Showing 2 changed files with 53 additions and 3 deletions.
diff --git a/pkg/descheduler/strategies/topologyspreadconstraint.go b/pkg/descheduler/strategies/topologyspreadconstraint.go
@@ -289,11 +289,11 @@ func balanceDomains(
  // however we still account for it "being evicted" so the algorithm can complete
  // TODO(@damemi): Since we don't order pods wrt their affinities, we should refactor this to skip the current pod
  // but still try to get the required # of movePods (instead of just chopping that value off the slice above)
- if aboveToEvict[k].Spec.NodeSelector != nil ||
+ if (aboveToEvict[k].Spec.NodeSelector != nil ||
  (aboveToEvict[k].Spec.Affinity != nil &&
  aboveToEvict[k].Spec.Affinity.NodeAffinity != nil &&
- aboveToEvict[k].Spec.Affinity.NodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution != nil &&
-  nodesPodFitsOnBesidesCurrent(aboveToEvict[k], nodeMap) == 0) {
+ aboveToEvict[k].Spec.Affinity.NodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution != nil)) &&
+ nodesPodFitsOnBesidesCurrent(aboveToEvict[k], nodeMap) == 0 {
  klog.V(2).InfoS("Ignoring pod for eviction due to node selector/affinity", "pod", klog.KObj(aboveToEvict[k]))
  continue
  }

diff --git a/pkg/descheduler/strategies/topologyspreadconstraint_test.go b/pkg/descheduler/strategies/topologyspreadconstraint_test.go
@@ -281,6 +281,56 @@ func TestTopologySpreadConstraint(t *testing.T) {
  strategy: api.DeschedulerStrategy{},
  namespaces: []string{"ns1"},
  },
+ {
+ name: "2 domains, sizes [4,0], maxSkew=1, move 2 pods since selector matches multiple nodes",
+ nodes: []*v1.Node{
+ test.BuildTestNode("n1", 2000, 3000, 10, func(n *v1.Node) {
+ n.Labels["zone"] = "zoneA"
+ n.Labels["region"] = "boston"
+ }),
+ test.BuildTestNode("n2", 2000, 3000, 10, func(n *v1.Node) {
+ n.Labels["zone"] = "zoneB"
+ n.Labels["region"] = "boston"
+ }),
+ },
+ pods: createTestPods([]testPodList{
+ {
+ count: 1,
+ node: "n1",
+ labels: map[string]string{"foo": "bar"},
+ constraints: []v1.TopologySpreadConstraint{
+ {
+ MaxSkew: 1,
+ TopologyKey: "zone",
+ WhenUnsatisfiable: v1.DoNotSchedule,
+ LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"foo": "bar"}},
+ },
+ },
+ nodeSelector: map[string]string{"region": "boston"},
+ },
+ {
+ count: 1,
+ node: "n1",
+ labels: map[string]string{"foo": "bar"},
+ nodeSelector: map[string]string{"region": "boston"},
+ },
+ {
+ count: 1,
+ node: "n1",
+ labels: map[string]string{"foo": "bar"},
+ nodeSelector: map[string]string{"region": "boston"},
+ },
+ {
+ count: 1,
+ node: "n1",
+ labels: map[string]string{"foo": "bar"},
+ nodeSelector: map[string]string{"region": "boston"},
+ },
+ }),
+ expectedEvictedCount: 2,
+ strategy: api.DeschedulerStrategy{},
+ namespaces: []string{"ns1"},
+ },
  {
  name: "3 domains, sizes [0, 1, 100], maxSkew=1, move 66 pods to get [34, 33, 34]",
  nodes: []*v1.Node{