Merge pull request #30291 from alculquicondor/patch-2

Fix whitespace in pod topology spread constraints page
This commit is contained in:
Kubernetes Prow Robot
2021-10-31 06:31:18 -07:00
committed by GitHub
@@ -236,41 +236,41 @@ The scheduler will skip the non-matching nodes from the skew calculations if the
Suppose you have a 5-node cluster ranging from zoneA to zoneC:
{{<mermaid>}}
graph BT
subgraph "zoneB"
p3(Pod) --> n3(Node3)
n4(Node4)
end
subgraph "zoneA"
p1(Pod) --> n1(Node1)
p2(Pod) --> n2(Node2)
end
{{<mermaid>}}
graph BT
subgraph "zoneB"
p3(Pod) --> n3(Node3)
n4(Node4)
end
subgraph "zoneA"
p1(Pod) --> n1(Node1)
p2(Pod) --> n2(Node2)
end
classDef plain fill:#ddd,stroke:#fff,stroke-width:4px,color:#000;
classDef k8s fill:#326ce5,stroke:#fff,stroke-width:4px,color:#fff;
classDef cluster fill:#fff,stroke:#bbb,stroke-width:2px,color:#326ce5;
class n1,n2,n3,n4,p1,p2,p3 k8s;
class p4 plain;
class zoneA,zoneB cluster;
{{< /mermaid >}}
classDef plain fill:#ddd,stroke:#fff,stroke-width:4px,color:#000;
classDef k8s fill:#326ce5,stroke:#fff,stroke-width:4px,color:#fff;
classDef cluster fill:#fff,stroke:#bbb,stroke-width:2px,color:#326ce5;
class n1,n2,n3,n4,p1,p2,p3 k8s;
class p4 plain;
class zoneA,zoneB cluster;
{{< /mermaid >}}
{{<mermaid>}}
graph BT
subgraph "zoneC"
n5(Node5)
end
{{<mermaid>}}
graph BT
subgraph "zoneC"
n5(Node5)
end
classDef plain fill:#ddd,stroke:#fff,stroke-width:4px,color:#000;
classDef k8s fill:#326ce5,stroke:#fff,stroke-width:4px,color:#fff;
classDef cluster fill:#fff,stroke:#bbb,stroke-width:2px,color:#326ce5;
class n5 k8s;
class zoneC cluster;
{{< /mermaid >}}
classDef plain fill:#ddd,stroke:#fff,stroke-width:4px,color:#000;
classDef k8s fill:#326ce5,stroke:#fff,stroke-width:4px,color:#fff;
classDef cluster fill:#fff,stroke:#bbb,stroke-width:2px,color:#326ce5;
class n5 k8s;
class zoneC cluster;
{{< /mermaid >}}
and you know that "zoneC" must be excluded. In this case, you can compose the yaml as below, so that "mypod" will be placed onto "zoneB" instead of "zoneC". Similarly `spec.nodeSelector` is also respected.
{{< codenew file="pods/topology-spread-constraints/one-constraint-with-nodeaffinity.yaml" >}}
{{< codenew file="pods/topology-spread-constraints/one-constraint-with-nodeaffinity.yaml" >}}
The scheduler doesn't have prior knowledge of all the zones or other topology domains that a cluster has. They are determined from the existing nodes in the cluster. This could lead to a problem in autoscaled clusters, when a node pool (or node group) is scaled to zero nodes and the user is expecting them to scale up, because, in this case, those topology domains won't be considered until there is at least one node in them.