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Update plugin names and deprecations for scheduler config

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Signed-off-by: Aldo Culquicondor <acondor@google.com>
This commit is contained in:
Aldo Culquicondor
2021-07-07 11:30:36 -04:00
parent 8b51854c67
commit a5c3c66fc9
2 changed files with 75 additions and 59 deletions
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content/en/docs/reference/scheduling/config.md
+67 -59
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@@ -19,14 +19,15 @@ Each stage is exposed in a extension point. Plugins provide scheduling behaviors
by implementing one or more of these extension points.
You can specify scheduling profiles by running `kube-scheduler --config <filename>`,
using the
[KubeSchedulerConfiguration (v1beta1)](/docs/reference/config-api/kube-scheduler-config.v1beta1/)
using the
KubeSchedulerConfiguration ([v1beta1](/docs/reference/config-api/kube-scheduler-config.v1beta1/)
or [v1beta2](/docs/reference/config-api/kube-scheduler-config.v1beta2/)).
struct.
A minimal configuration looks as follows:
```yaml
apiVersion: kubescheduler.config.k8s.io/v1beta1
apiVersion: kubescheduler.config.k8s.io/v1beta2
kind: KubeSchedulerConfiguration
clientConnection:
kubeconfig: /etc/srv/kubernetes/kube-scheduler/kubeconfig
@@ -48,38 +49,41 @@ You can configure a single instance of `kube-scheduler` to run
Scheduling happens in a series of stages that are exposed through the following
extension points:
1. `QueueSort`: These plugins provide an ordering function that is used to
1. `queueSort`: These plugins provide an ordering function that is used to
sort pending Pods in the scheduling queue. Exactly one queue sort plugin
may be enabled at a time.
1. `PreFilter`: These plugins are used to pre-process or check information
1. `preFilter`: These plugins are used to pre-process or check information
about a Pod or the cluster before filtering. They can mark a pod as
unschedulable.
1. `Filter`: These plugins are the equivalent of Predicates in a scheduling
1. `filter`: These plugins are the equivalent of Predicates in a scheduling
Policy and are used to filter out nodes that can not run the Pod. Filters
are called in the configured order. A pod is marked as unschedulable if no
nodes pass all the filters.
1. `PreScore`: This is an informational extension point that can be used
1. `postFilter`: These plugins are called in their configured order when no
feasible nodes were found for the pod. If any `postFilter` plugin marks the
Pod _schedulable_, the remaining plugins are not called.
1. `preScore`: This is an informational extension point that can be used
for doing pre-scoring work.
1. `Score`: These plugins provide a score to each node that has passed the
1. `score`: These plugins provide a score to each node that has passed the
filtering phase. The scheduler will then select the node with the highest
weighted scores sum.
1. `Reserve`: This is an informational extension point that notifies plugins
1. `reserve`: This is an informational extension point that notifies plugins
when resources have been reserved for a given Pod. Plugins also implement an
`Unreserve` call that gets called in the case of failure during or after
`Reserve`.
1. `Permit`: These plugins can prevent or delay the binding of a Pod.
1. `PreBind`: These plugins perform any work required before a Pod is bound.
1. `Bind`: The plugins bind a Pod to a Node. Bind plugins are called in order
1. `permit`: These plugins can prevent or delay the binding of a Pod.
1. `preBind`: These plugins perform any work required before a Pod is bound.
1. `bind`: The plugins bind a Pod to a Node. `bind` plugins are called in order
and once one has done the binding, the remaining plugins are skipped. At
least one bind plugin is required.
1. `PostBind`: This is an informational extension point that is called after
1. `postBind`: This is an informational extension point that is called after
a Pod has been bound.
For each extension point, you could disable specific [default plugins](#scheduling-plugins)
or enable your own. For example:
```yaml
apiVersion: kubescheduler.config.k8s.io/v1beta1
apiVersion: kubescheduler.config.k8s.io/v1beta2
kind: KubeSchedulerConfiguration
profiles:
- plugins:
@@ -99,106 +103,109 @@ desired.
### Scheduling plugins
1. `UnReserve`: This is an informational extension point that is called if
a Pod is rejected after being reserved and put on hold by a `Permit` plugin.
## Scheduling plugins
The following plugins, enabled by default, implement one or more of these
extension points:
- `SelectorSpread`: Favors spreading across nodes for Pods that belong to
{{< glossary_tooltip text="Services" term_id="service" >}},
{{< glossary_tooltip text="ReplicaSets" term_id="replica-set" >}} and
{{< glossary_tooltip text="StatefulSets" term_id="statefulset" >}}.
Extension points: `PreScore`, `Score`.
- `ImageLocality`: Favors nodes that already have the container images that the
Pod runs.
Extension points: `Score`.
Extension points: `score`.
- `TaintToleration`: Implements
[taints and tolerations](/docs/concepts/scheduling-eviction/taint-and-toleration/).
Implements extension points: `Filter`, `Prescore`, `Score`.
Implements extension points: `filter`, `preScore`, `score`.
- `NodeName`: Checks if a Pod spec node name matches the current node.
Extension points: `Filter`.
Extension points: `filter`.
- `NodePorts`: Checks if a node has free ports for the requested Pod ports.
Extension points: `PreFilter`, `Filter`.
Extension points: `preFilter`, `filter`.
- `NodePreferAvoidPods`: Scores nodes according to the node
{{< glossary_tooltip text="annotation" term_id="annotation" >}}
`scheduler.alpha.kubernetes.io/preferAvoidPods`.
Extension points: `Score`.
Extension points: `score`.
- `NodeAffinity`: Implements
[node selectors](/docs/concepts/scheduling-eviction/assign-pod-node/#nodeselector)
and [node affinity](/docs/concepts/scheduling-eviction/assign-pod-node/#node-affinity).
Extension points: `Filter`, `Score`.
Extension points: `filter`, `score`.
- `PodTopologySpread`: Implements
[Pod topology spread](/docs/concepts/workloads/pods/pod-topology-spread-constraints/).
Extension points: `PreFilter`, `Filter`, `PreScore`, `Score`.
Extension points: `preFilter`, `filter`, `preScore`, `score`.
- `NodeUnschedulable`: Filters out nodes that have `.spec.unschedulable` set to
true.
Extension points: `Filter`.
Extension points: `filter`.
- `NodeResourcesFit`: Checks if the node has all the resources that the Pod is
requesting.
Extension points: `PreFilter`, `Filter`.
requesting. The score can use one of three strategies: `LeastAllocated`
(default), `MostAllocated` and `RequestedToCapacityRatio`.
Extension points: `preFilter`, `filter`, `score`.
- `NodeResourcesBalancedAllocation`: Favors nodes that would obtain a more
balanced resource usage if the Pod is scheduled there.
Extension points: `Score`.
- `NodeResourcesLeastAllocated`: Favors nodes that have a low allocation of
resources.
Extension points: `Score`.
Extension points: `score`.
- `VolumeBinding`: Checks if the node has or if it can bind the requested
{{< glossary_tooltip text="volumes" term_id="volume" >}}.
Extension points: `PreFilter`, `Filter`, `Reserve`, `PreBind`, `Score`.
Extension points: `preFilter`, `filter`, `reserve`, `preBind`, `score`.
{{< note >}}
`Score` extension point is enabled when `VolumeCapacityPriority` feature is
`score` extension point is enabled when `VolumeCapacityPriority` feature is
enabled. It prioritizes the smallest PVs that can fit the requested volume
size.
{{< /note >}}
- `VolumeRestrictions`: Checks that volumes mounted in the node satisfy
restrictions that are specific to the volume provider.
Extension points: `Filter`.
Extension points: `filter`.
- `VolumeZone`: Checks that volumes requested satisfy any zone requirements they
might have.
Extension points: `Filter`.
Extension points: `filter`.
- `NodeVolumeLimits`: Checks that CSI volume limits can be satisfied for the
node.
Extension points: `Filter`.
Extension points: `filter`.
- `EBSLimits`: Checks that AWS EBS volume limits can be satisfied for the node.
Extension points: `Filter`.
Extension points: `filter`.
- `GCEPDLimits`: Checks that GCP-PD volume limits can be satisfied for the node.
Extension points: `Filter`.
Extension points: `filter`.
- `AzureDiskLimits`: Checks that Azure disk volume limits can be satisfied for
the node.
Extension points: `Filter`.
Extension points: `filter`.
- `InterPodAffinity`: Implements
[inter-Pod affinity and anti-affinity](/docs/concepts/scheduling-eviction/assign-pod-node/#inter-pod-affinity-and-anti-affinity).
Extension points: `PreFilter`, `Filter`, `PreScore`, `Score`.
Extension points: `preFilter`, `filter`, `preScore`, `score`.
- `PrioritySort`: Provides the default priority based sorting.
Extension points: `QueueSort`.
Extension points: `queueSort`.
- `DefaultBinder`: Provides the default binding mechanism.
Extension points: `Bind`.
Extension points: `bind`.
- `DefaultPreemption`: Provides the default preemption mechanism.
Extension points: `PostFilter`.
Extension points: `postFilter`.
You can also enable the following plugins, through the component config APIs,
that are not enabled by default:
- `SelectorSpread`: Favors spreading across nodes for Pods that belong to
{{< glossary_tooltip text="Services" term_id="service" >}},
{{< glossary_tooltip text="ReplicaSets" term_id="replica-set" >}} and
{{< glossary_tooltip text="StatefulSets" term_id="statefulset" >}}.
Extension points: `preScore`, `score`.
- `CinderLimits`: Checks that [OpenStack Cinder](https://docs.openstack.org/cinder/)
volume limits can be satisfied for the node.
Extension points: `filter`.
The following plugins are deprecated and can only be enabled in a `v1beta1`
configuration:
- `NodeResourcesLeastAllocated`: Favors nodes that have a low allocation of
resources.
Extension points: `score`.
- `NodeResourcesMostAllocated`: Favors nodes that have a high allocation of
resources.
Extension points: `Score`.
Extension points: `score`.
- `RequestedToCapacityRatio`: Favor nodes according to a configured function of
the allocated resources.
Extension points: `Score`.
- `CinderVolume`: Checks that OpenStack Cinder volume limits can be satisfied
for the node.
Extension points: `Filter`.
Extension points: `score`.
- `NodeLabel`: Filters and / or scores a node according to configured
{{< glossary_tooltip text="label(s)" term_id="label" >}}.
Extension points: `Filter`, `Score`.
Extension points: `filter`, `score`.
- `ServiceAffinity`: Checks that Pods that belong to a
{{< glossary_tooltip term_id="service" >}} fit in a set of nodes defined by
configured labels. This plugin also favors spreading the Pods belonging to a
Service across nodes.
Extension points: `PreFilter`, `Filter`, `Score`.
Extension points: `preFilter`, `filter`, `score`.
- `NodePreferAvoidPods`: Prioritizes nodes according to the node annotation
`scheduler.alpha.kubernetes.io/preferAvoidPods`.
Extension points: `score`.
### Multiple profiles
@@ -211,7 +218,7 @@ profiles: one with the default plugins and one with all scoring plugins
disabled.
```yaml
apiVersion: kubescheduler.config.k8s.io/v1beta1
apiVersion: kubescheduler.config.k8s.io/v1beta2
kind: KubeSchedulerConfiguration
profiles:
- schedulerName: default-scheduler
@@ -243,7 +250,7 @@ list.
{{< /note >}}
{{< note >}}
All profiles must use the same plugin in the QueueSort extension point and have
All profiles must use the same plugin in the `queueSort` extension point and have
the same configuration parameters (if applicable). This is because the scheduler
only has one pending pods queue.
{{< /note >}}
@@ -252,5 +259,6 @@ only has one pending pods queue.
* Read the [kube-scheduler reference](/docs/reference/command-line-tools-reference/kube-scheduler/)
* Learn about [scheduling](/docs/concepts/scheduling-eviction/kube-scheduler/)
* Read the [kube-scheduler configuration (v1beta2)](/docs/reference/config-api/kube-scheduler-config.v1beta2/) reference
* Read the [kube-scheduler configuration (v1beta1)](/docs/reference/config-api/kube-scheduler-config.v1beta1/) reference