Configure Multiple Schedulers [page]deterministic

Kubernetes ships with a default scheduler that is described [here](/docs/reference/command-line-tools-reference/kube-scheduler/). If the default scheduler does not suit your needs you can implement your own scheduler. Moreover, you can even run multiple schedulers simultaneously alongside the default scheduler and instruct Kubernetes what scheduler to use for each of your pods. Let's learn how to run multiple schedulers in Kubernetes with an example.

A detailed description of how to implement a scheduler is outside the scope of this document. Please refer to the kube-scheduler implementation in [pkg/scheduler](https://github.com/kubernetes/kubernetes/tree/master/pkg/scheduler) in the Kubernetes source directory for a canonical example.

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## Package the scheduler

Package your scheduler binary into a container image. For the purposes of this example, you can use the default scheduler (kube-scheduler) as your second scheduler. Clone the [Kubernetes source code from GitHub](https://github.com/kubernetes/kubernetes) and build the source.

```shell git clone https://github.com/kubernetes/kubernetes.git cd kubernetes make ```

Create a container image containing the kube-scheduler binary. Here is the `Dockerfile` to build the image:

```docker FROM busybox ADD ./_output/local/bin/linux/amd64/kube-scheduler /usr/local/bin/kube-scheduler ```

Save the file as `Dockerfile`, build the image and push it to a registry. This example pushes the image to [Google Container Registry (GCR)](https://cloud.google.com/container-registry/). For more details, please read the GCR [documentation](https://cloud.google.com/container-registry/docs/). Alternatively you can also use the [docker hub](https://hub.docker.com/search?q=). For more details refer to the docker hub [documentation](https://docs.docker.com/docker-hub/repos/create/#create-a-repository).

```shell docker build -t gcr.io/my-gcp-project/my-kube-scheduler:1.0 . # The image name and the repository gcloud docker -- push gcr.io/my-gcp-project/my-kube-scheduler:1.0 # used in here is just an example ```

## Define a Kubernetes Deployment for the scheduler

Now that you have your scheduler in a container image, create a pod configuration for it and run it in your Kubernetes cluster. But instead of creating a pod directly in the cluster, you can use a [Deployment](/docs/concepts/workloads/controllers/deployment/) for this example. A [Deployment](/docs/concepts/workloads/controllers/deployment/) manages a [Replica Set](/docs/concepts/workloads/controllers/replicaset/) which in turn manages the pods, thereby making the scheduler resilient to failures. Here is the deployment config. Save it as `my-scheduler.yaml`:

In the above manifest, you use a [KubeSchedulerConfiguration](/docs/reference/scheduling/config/) to customize the behavior of your scheduler implementation. This configuration has been passed to the `kube-scheduler` during initialization with the `--config` option. The `my-scheduler-config` ConfigMap stores the configuration file. The Pod of the`my-scheduler` Deployment mounts the `my-scheduler-config` ConfigMap as a volume.

In the aforementioned Scheduler Configuration, your scheduler implementation is represented via a [KubeSchedulerProfile](/docs/reference/config-api/kube-scheduler-config.v1/#kubescheduler-config-k8s-io-v1-KubeSchedulerProfile).

> Note: To determine if a scheduler is responsible for scheduling a specific Pod, the `spec.schedulerName` field in a PodTemplate or Pod manifest must match the `schedulerName` field of the `KubeSchedulerProfile`. All schedulers running in the cluster must have unique names.

Also, note that you create a dedicated service account `my-scheduler` and bind the ClusterRole `system:kube-scheduler` to it so that it can acquire the same privileges as `kube-scheduler`.

Please see the [kube-scheduler documentation](/docs/reference/command-line-tools-reference/kube-scheduler/) for detailed description of other command line a …(trimmed)