diff --git a/docs/concepts/configuration/assign-pod-node.md b/docs/concepts/configuration/assign-pod-node.md index a99896a2ac..7ef1b40ba0 100644 --- a/docs/concepts/configuration/assign-pod-node.md +++ b/docs/concepts/configuration/assign-pod-node.md @@ -88,7 +88,7 @@ feature, currently in beta, greatly expands the types of constraints you can exp 3. you can constrain against labels on other pods running on the node (or other topological domain), rather than against labels on the node itself, which allows rules about which pods can and cannot be co-located -The affinity feature consists of two types of affinity, "node affinity" and "inter-pod affinity/anti-affinity." +The affinity feature consists of two types of affinity, "node affinity" and "inter-pod affinity/anti-affinity". Node affinity is like the existing `nodeSelector` (but with the first two benefits listed above), while inter-pod affinity/anti-affinity constrains against pod labels rather than node labels, as described in the third item listed above, in addition to having the first and second properties listed above. @@ -147,7 +147,7 @@ For more information on node affinity, see the design doc Inter-pod affinity and anti-affinity were introduced in Kubernetes 1.4. Inter-pod affinity and anti-affinity allow you to constrain which nodes your pod is eligible to be scheduled *based on labels on pods that are already running on the node* rather than based on labels on nodes. The rules are of the form "this pod should (or, in the case of -anti-affinity, should not) run in an X if that X is already running one or more pods that meet rule Y." Y is expressed +anti-affinity, should not) run in an X if that X is already running one or more pods that meet rule Y". Y is expressed as a LabelSelector with an associated list of namespaces (or "all" namespaces); unlike nodes, because pods are namespaced (and therefore the labels on pods are implicitly namespaced), a label selector over pod labels must specify which namespaces the selector should apply to. Conceptually X is a topology domain @@ -203,7 +203,7 @@ empty `topologyKey` is not allowed. In addition to `labelSelector` and `topologyKey`, you can optionally specify a list `namespaces` of namespaces which the `labelSelector` should match against (this goes at the same level of the definition as `labelSelector` and `topologyKey`). If omitted, it defaults to the namespace of the pod where the affinity/anti-affinity definition appears. -If defined but empty, it means "all namespaces." +If defined but empty, it means "all namespaces". All `matchExpressions` associated with `requiredDuringSchedulingIgnoredDuringExecution` affinity and anti-affinity must be satisfied for the pod to be scheduled onto a node.