# Scheduler plugins for Kubernetes [scheduler-plugins](https://github.com/kubernetes-sigs/scheduler-plugins) is out-of-tree scheduler plugins based on the [scheduler framework](https://kubernetes.io/docs/concepts/scheduling-eviction/scheduling-framework/). The kube-scheduler binary includes a list of plugins: - [CapacityScheduling](https://github.com/kubernetes-sigs/scheduler-plugins/tree/master/pkg/capacityscheduling) [Beta] - [CoScheduling](https://github.com/kubernetes-sigs/scheduler-plugins/tree/master/pkg/coscheduling) [Beta] - [NodeResources](https://github.com/kubernetes-sigs/scheduler-plugins/tree/master/pkg/noderesources) [Beta] - [NodeResouceTopology](https://github.com/kubernetes-sigs/scheduler-plugins/blob/master/pkg/noderesourcetopology/README.md) [Beta] - [PreemptionToleration](https://github.com/kubernetes-sigs/scheduler-plugins/blob/master/pkg/preemptiontoleration/README.md) [Alpha] - [Trimaran](https://github.com/kubernetes-sigs/scheduler-plugins/blob/master/pkg/trimaran/README.md) [Alpha] - [NetworkAware](https://github.com/kubernetes-sigs/scheduler-plugins/blob/master/pkg/networkaware/README.md) [Sample] - [CrossNodePreemption](https://github.com/kubernetes-sigs/scheduler-plugins/blob/master/pkg/crossnodepreemption/README.md) [Sample] - [PodState](https://github.com/kubernetes-sigs/scheduler-plugins/blob/master/pkg/podstate/README.md) [Sample] - [QualityOfService](https://github.com/kubernetes-sigs/scheduler-plugins/blob/master/pkg/qos/README.md) [Sample] Currently, we use [helm chart](https://github.com/kubernetes-sigs/scheduler-plugins/blob/master/manifests/install/charts/as-a-second-scheduler/README.md#installing-the-chart) to install the scheduler plugins, so that a second scheduler would be created and running. **Note that running multi-scheduler will inevitably encounter resource conflicts when the cluster is short of resources**. ## Compatibility Matrix There are requirements for the version of Kubernetes, please see [Compatibility Matrix ](https://github.com/kubernetes-sigs/scheduler-plugins/tree/master?tab=readme-ov-file#compatibility-matrix). It deserves our attention. | Scheduler Plugins | Compiled With K8s Version | | ----------------- | ------------------------- | | v0.28.9 | v1.28.9 | | v0.27.8 | v1.27.8 | ## Turning it on The `scheduler_plugins_enabled` option is used to enable the installation of scheduler plugins. You can enable or disable some plugins by setting the `scheduler_plugins_enabled_plugins` or `scheduler_plugins_disabled_plugins` option. They must be in the list we mentioned above. In addition, to use custom plugin configuration, set a value for `scheduler_plugins_plugin_config` option. For example, for Coscheduling plugin, you want to customize the permit waiting timeout to 10 seconds: ```yaml scheduler_plugins_plugin_config: - name: Coscheduling args: permitWaitingTimeSeconds: 10 # default is 60 ``` ## Leverage plugin Once the plugin is installed, we can apply CRs into cluster. For example, if using `CoScheduling`, we can apply the CR and test the deployment in the [example](https://github.com/kubernetes-sigs/scheduler-plugins/blob/master/doc/install.md#test-coscheduling).