# Orchestrate a Local Cluster with Kubernetes

On top of CockroachDB's built-in automation, you can use a third-party orchestration system to simplify and automate even more of your operations, from deployment to scaling to overall cluster management.

This page walks you through a simple demonstration, using the open-source Kubernetes orchestration system. Using either the CockroachDB Helm chart or a few configuration files, you'll quickly create a 3-node local cluster. You'll run some SQL commands against the cluster and then simulate node failure, watching how Kubernetes auto-restarts without the need for any manual intervention. You'll then scale the cluster with a single command before shutting the cluster down, again with a single command.

Note:

To orchestrate a physically distributed cluster in production, see Orchestrated Deployments. To deploy a 30-day free CockroachCloud cluster instead of running CockroachDB yourself, see the Quickstart.

## Before you begin

Before getting started, it's helpful to review some Kubernetes-specific terminology:

Feature | Description
--- | ---
minikube | This is the tool you'll use to run a Kubernetes cluster inside a VM on your local workstation.
pod | A pod is a group of one of more Docker containers. In this tutorial, all pods will run on your local workstation, each containing one Docker container running a single CockroachDB node. You'll start with 3 pods and grow to 4.
StatefulSet | A StatefulSet is a group of pods treated as stateful units, where each pod has distinguishable network identity and always binds back to the same persistent storage on restart. StatefulSets are considered stable as of Kubernetes version 1.9 after reaching beta in version 1.5.
persistent volume | A persistent volume is a piece of storage mounted into a pod. The lifetime of a persistent volume is decoupled from the lifetime of the pod that's using it, ensuring that each CockroachDB node binds back to the same storage on restart. When using `minikube`, persistent volumes are external temporary directories that endure until they are manually deleted or until the entire Kubernetes cluster is deleted.
persistent volume claim | When pods are created (one per CockroachDB node), each pod will request a persistent volume claim to “claim” durable storage for its node.

## Step 1. Start Kubernetes

1. Follow Kubernetes' documentation to install `minikube`, the tool used to run Kubernetes locally, for your OS. This includes installing a hypervisor and `kubectl`, the command-line tool used to manage Kubernetes from your local workstation.

   Note:
   Make sure you install `minikube` version 0.21.0 or later. Earlier versions do not include a Kubernetes server that supports the `maxUnavailability` field and `PodDisruptionBudget` resource type used in the CockroachDB StatefulSet configuration.

2. Start a local Kubernetes cluster:

       $ minikube start

## Step 2. Start CockroachDB

To start your CockroachDB cluster, you can either use our StatefulSet configuration and related files directly, or you can use the Helm package manager for Kubernetes to simplify the process.

Download and modify our StatefulSet configuration, depending on how you want to sign your certificates.

Warning:

Some environments, such as Amazon EKS, do not support certificates signed by Kubernetes' built-in CA. In this case, use the second configuration below.

- Using the Kubernetes CA: `cockroachdb-statefulset-secure.yaml`.

      $ curl -O https://raw.githubusercontent.com/cockroachdb/cockroach/master/cloud/kubernetes/cockroachdb-statefulset-secure.yaml

- Using a non-Kubernetes CA: `cockroachdb-statefulset.yaml`

      $ curl -O https://raw.githubusercontent.com/cockroachdb/cockroach/master/cloud/kubernetes/bring-your-own-certs/cockroachdb-statefulset.yaml

Tip:

If you change the StatefulSet name from the default `cockroachdb`, be sure to start and end with an alphanumeric character and otherwise use lowercase alphanumeric characters, `-`, or `.` so as to comply with CSR naming requirements.

#### Initialize the cluster

Choose the authentication method that corresponds to the StatefulSet configuration you downloaded and modified above.

- Kubernetes CA
- Non-Kubernetes CA

Tip:

The StatefulSet configuration sets all CockroachDB nodes to log to `stderr`, so if you ever need access to a pod/node's logs to troubleshoot, use `kubectl logs <podname>` rather than checking the log on the persistent volume.

##### Kubernetes CA

1. Use the config file you downloaded to create the StatefulSet that automatically creates 3 pods, each running a CockroachDB node:

       $ kubectl create -f cockroachdb-statefulset-secure.yaml

       serviceaccount/cockroachdb created
       role.rbac.authorization.k8s.io/cockroachdb created
       clusterrole.rbac.authorization.k8s.io/cockroachdb created
       rolebinding.rbac.authorization.k8s.io/cockroachdb created
       clusterrolebinding.rbac.authorization.k8s.io/cockroachdb created
       service/cockroachdb-public created
       service/cockroachdb created
       poddisruptionbudget.policy/cockroachdb-budget created
       statefulset.apps/cockroachdb created

2. As each pod is created, it issues a Certificate Signing Request, or CSR, to have the node's certificate signed by the Kubernetes CA. You must manually check and approve each node's certificates, at which point the CockroachDB node is started in the pod.

   1. Get the names of the `Pending` CSRs:

          $ kubectl get csr

          NAME                         AGE   REQUESTOR                                   CONDITION
          default.node.cockroachdb-0   1m    system:serviceaccount:default:cockroachdb   Pending
          default.node.cockroachdb-1   1m    system:serviceaccount:default:cockroachdb   Pending
          default.node.cockroachdb-2   1m    system:serviceaccount:default:cockroachdb   Pending
          ...

      If you do not see a `Pending` CSR, wait a minute and try again.

   2. Examine the CSR for the first pod:

          $ kubectl describe csr default.node.cockroachdb-0

          Name:               default.node.cockroachdb-0
          Labels:             <none>
          Annotations:        <none>
          CreationTimestamp:  Thu, 09 Nov 2017 13:39:37 -0500
          Requesting User:    system:serviceaccount:default:cockroachdb
          Status:             Pending
          Subject:
            Common Name:    node
            Serial Number:
            Organization:   Cockroach
          Subject Alternative Names:
                   DNS Names:     localhost
                                  cockroachdb-0.cockroachdb.default.svc.cluster.local
                                  cockroachdb-0.cockroachdb
                                  cockroachdb-public
                                  cockroachdb-public.default.svc.cluster.local
                   IP Addresses:  127.0.0.1
                                  10.48.1.6
          Events:  <none>

   3. If everything looks correct, approve the CSR for the first pod:

          $ kubectl certificate approve default.node.cockroachdb-0

          certificatesigningrequest "default.node.cockroachdb-0" approved

   4. Repeat steps 2 and 3 for the other 2 pods.

3. Initialize the CockroachDB cluster:

   1. Confirm that three pods are `Running` successfully. Note that they will not be considered `Ready` until after the cluster has been initialized:

          $ kubectl get pods

          NAME            READY     STATUS    RESTARTS   AGE
          cockroachdb-0   0/1       Running   0          2m
          cockroachdb-1   0/1       Running   0          2m
          cockroachdb-2   0/1       Running   0          2m

   2. Confirm that the persistent volumes and corresponding claims were created successfully for all three pods:

          $ kubectl get pv

          NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                           STORAGECLASS   REASON   AGE
          pvc-9e435563-fb2e-11e9-a65c-42010a8e0fca   100Gi      RWO            Delete           Bound    default/datadir-cockroachdb-0   standard                51m
          pvc-9e47d820-fb2e-11e9-a65c-42010a8e0fca   100Gi      RWO            Delete           Bound    default/datadir-cockroachdb-1   standard                51m
          pvc-9e4f57f0-fb2e-11e9-a65c-42010a8e0fca   100Gi      RWO            Delete           Bound    default/datadir-cockroachdb-2   standard                51m

   3. Use our `cluster-init-secure.yaml` file to perform a one-time initialization that joins the CockroachDB nodes into a single cluster:

          $ kubectl create \
          -f https://raw.githubusercontent.com/cockroachdb/cockroach/master/cloud/kubernetes/cluster-init-secure.yaml

          job.batch/cluster-init-secure created

   4. Approve the CSR for the one-off pod from which cluster initialization happens:

          $ kubectl certificate approve default.client.root

          certificatesigningrequest.certificates.k8s.io/default.client.root approved

   5. Confirm that cluster initialization has completed successfully. The job should be considered successful and the Kubernetes pods should soon be considered `Ready`:

          $ kubectl get job cluster-init-secure

          NAME                  COMPLETIONS   DURATION   AGE
          cluster-init-secure   1/1           23s        35s

          $ kubectl get pods

          NAME                        READY     STATUS      RESTARTS   AGE
          cluster-init-secure-q8s7v   0/1       Completed   0          55s
          cockroachdb-0               1/1       Running     0          3m
          cockroachdb-1               1/1       Running     0          3m
          cockroachdb-2               1/1       Running     0          3m

##### Non-Kubernetes CA

Note:

The below steps use `cockroach cert` commands to quickly generate and sign the CockroachDB node and client certificates. Read our Authentication docs to learn about other methods of signing certificates.

1. Create two directories:

       $ mkdir certs

       $ mkdir my-safe-directory

   Directory | Description
   --- | ---
   `certs` | You'll generate your CA certificate and all node and client certificates and keys in this directory.
   `my-safe-directory` | You'll generate your CA key in this directory and then reference the key when generating node and client certificates.

2. Create the CA certificate and key pair:

       $ cockroach cert create-ca \
       --certs-dir=certs \
       --ca-key=my-safe-directory/ca.key

3. Create a client certificate and key pair for the root user:

       $ cockroach cert create-client \
       root \
       --certs-dir=certs \
       --ca-key=my-safe-directory/ca.key

4. Upload the client certificate and key to the Kubernetes cluster as a secret:

       $ kubectl create secret \
       generic cockroachdb.client.root \
       --from-file=certs

       secret/cockroachdb.client.root created

5. Create the certificate and key pair for your CockroachDB nodes:

       $ cockroach cert create-node \
       localhost 127.0.0.1 \
       cockroachdb-public \
       cockroachdb-public.default \
       cockroachdb-public.default.svc.cluster.local \
       *.cockroachdb \
       *.cockroachdb.default \
       *.cockroachdb.default.svc.cluster.local \
       --certs-dir=certs \
       --ca-key=my-safe-directory/ca.key

6. Upload the node certificate and key to the Kubernetes cluster as a secret:

       $ kubectl create secret \
       generic cockroachdb.node \
       --from-file=certs

       secret/cockroachdb.node created

7. Check that the secrets were created on the cluster:

       $ kubectl get secrets

       NAME                      TYPE                                  DATA   AGE
       cockroachdb.client.root   Opaque                                3      41m
       cockroachdb.node          Opaque                                5      14s
       default-token-6qjdb       kubernetes.io/service-account-token   3      4m

8. Use the config file you downloaded to create the StatefulSet that automatically creates 3 pods, each running a CockroachDB node:

       $ kubectl create -f cockroachdb-statefulset.yaml

       serviceaccount/cockroachdb created
       role.rbac.authorization.k8s.io/cockroachdb created
       rolebinding.rbac.authorization.k8s.io/cockroachdb created
       service/cockroachdb-public created
       service/cockroachdb created
       poddisruptionbudget.policy/cockroachdb-budget created
       statefulset.apps/cockroachdb created

9. Initialize the CockroachDB cluster:

   1. Confirm that three pods are `Running` successfully. Note that they will not be considered `Ready` until after the cluster has been initialized:

          $ kubectl get pods

          NAME            READY     STATUS    RESTARTS   AGE
          cockroachdb-0   0/1       Running   0          2m
          cockroachdb-1   0/1       Running   0          2m
          cockroachdb-2   0/1       Running   0          2m

   2. Confirm that the persistent volumes and corresponding claims were created successfully for all three pods:

          $ kubectl get pv

          NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                           STORAGECLASS   REASON   AGE
          pvc-9e435563-fb2e-11e9-a65c-42010a8e0fca   100Gi      RWO            Delete           Bound    default/datadir-cockroachdb-0   standard                51m
          pvc-9e47d820-fb2e-11e9-a65c-42010a8e0fca   100Gi      RWO            Delete           Bound    default/datadir-cockroachdb-1   standard                51m
          pvc-9e4f57f0-fb2e-11e9-a65c-42010a8e0fca   100Gi      RWO            Delete           Bound    default/datadir-cockroachdb-2   standard                51m

   3. Run `cockroach init` on one of the pods to complete the node startup process and have them join together as a cluster:

          $ kubectl exec -it cockroachdb-0 \
          -- /cockroach/cockroach init \
          --certs-dir=/cockroach/cockroach-certs

          Cluster successfully initialized

   4. Confirm that cluster initialization has completed successfully. The job should be considered successful and the Kubernetes pods should soon be considered `Ready`:

          $ kubectl get pods

          NAME            READY     STATUS    RESTARTS   AGE
          cockroachdb-0   1/1       Running   0          3m
          cockroachdb-1   1/1       Running   0          3m
          cockroachdb-2   1/1       Running   0          3m

1. Install the Helm client (version 3.0 or higher) and add the `cockroachdb` chart repository:

       $ helm repo add cockroachdb https://charts.cockroachdb.com/

       "cockroachdb" has been added to your repositories

2. Update your Helm chart repositories to ensure that you're using the latest CockroachDB chart:

       $ helm repo update

3. Modify our Helm chart's `values.yaml` parameters for your deployment scenario.

   Create a `my-values.yaml` file to override the defaults. For a secure deployment, set `tls.enabled` to true:

       tls:
         enabled: true

4. Install the CockroachDB Helm chart.

   Provide a "release" name to identify and track this particular deployment of the chart, and override the default values with those in `my-values.yaml`.

   Note:

   This tutorial uses `my-release` as the release name. If you use a different value, be sure to adjust the release name in subsequent commands. Also be sure to start and end the name with an alphanumeric character and otherwise use lowercase alphanumeric characters, `-`, or `.` so as to comply with CSR naming requirements.

       $ helm install my-release --values my-values.yaml cockroachdb/cockroachdb

   Behind the scenes, this command uses our `cockroachdb-statefulset.yaml` file to create the StatefulSet that automatically creates 3 pods, each with a CockroachDB node running inside it, where each pod has distinguishable network identity and always binds back to the same persistent storage on restart.

5. As each pod is created, it issues a Certificate Signing Request, or CSR, to have the CockroachDB node's certificate signed by the Kubernetes CA. You must manually check and approve each node's certificate, at which point the CockroachDB node is started in the pod.

   1. Get the names of the `Pending` CSRs:

          $ kubectl get csr

          NAME                                    AGE       REQUESTOR                                              CONDITION
          default.client.root                     21s       system:serviceaccount:default:my-release-cockroachdb   Pending
          default.node.my-release-cockroachdb-0   15s       system:serviceaccount:default:my-release-cockroachdb   Pending
          default.node.my-release-cockroachdb-1   16s       system:serviceaccount:default:my-release-cockroachdb   Pending
          default.node.my-release-cockroachdb-2   15s       system:serviceaccount:default:my-release-cockroachdb   Pending
          ...

      If you do not see a `Pending` CSR, wait a minute and try again.

   2. Examine the CSR for the first pod:

          $ kubectl describe csr default.node.my-release-cockroachdb-0

          Name:               default.node.my-release-cockroachdb-0
          Labels:             <none>
          Annotations:        <none>
          CreationTimestamp:  Mon, 10 Dec 2018 05:36:35 -0500
          Requesting User:    system:serviceaccount:default:my-release-cockroachdb
          Status:             Pending
          Subject:
            Common Name:    node
            Serial Number:
            Organization:   Cockroach
          Subject Alternative Names:
                   DNS Names:     localhost
                                  my-release-cockroachdb-0.my-release-cockroachdb.default.svc.cluster.local
                                  my-release-cockroachdb-0.my-release-cockroachdb
                                  my-release-cockroachdb-public
                                  my-release-cockroachdb-public.default.svc.cluster.local
                   IP Addresses:  127.0.0.1
          Events:  <none>

   3. If everything looks correct, approve the CSR for the first pod:

          $ kubectl certificate approve default.node.my-release-cockroachdb-0

          certificatesigningrequest.certificates.k8s.io/default.node.my-release-cockroachdb-0 approved

   4. Repeat steps 2 and 3 for the other 2 pods.

6. Confirm that three pods are `Running` successfully:

       $ kubectl get pods

       NAME                                READY     STATUS     RESTARTS   AGE
       my-release-cockroachdb-0            0/1       Running    0          6m
       my-release-cockroachdb-1            0/1       Running    0          6m
       my-release-cockroachdb-2            0/1       Running    0          6m
       my-release-cockroachdb-init-hxzsc   0/1       Init:0/1   0          6m

7. Approve the CSR for the one-off pod from which cluster initialization happens:

       $ kubectl certificate approve default.client.root

       certificatesigningrequest.certificates.k8s.io/default.client.root approved

8. Confirm that CockroachDB cluster initialization has completed successfully, with the pods for CockroachDB showing `1/1` under `READY` and the pod for initialization showing `COMPLETED` under `STATUS`:

       $ kubectl get pods

       NAME                                READY     STATUS      RESTARTS   AGE
       my-release-cockroachdb-0            1/1       Running     0          8m
       my-release-cockroachdb-1            1/1       Running     0          8m
       my-release-cockroachdb-2            1/1       Running     0          8m
       my-release-cockroachdb-init-hxzsc   0/1       Completed   0          1h

9. Confirm that the persistent volumes and corresponding claims were created successfully for all three pods:

       $ kubectl get pv

       NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS    CLAIM                                      STORAGECLASS   REASON    AGE
       pvc-71019b3a-fc67-11e8-a606-080027ba45e5   100Gi      RWO            Delete           Bound     default/datadir-my-release-cockroachdb-0   standard                 11m
       pvc-7108e172-fc67-11e8-a606-080027ba45e5   100Gi      RWO            Delete           Bound     default/datadir-my-release-cockroachdb-1   standard                 11m
       pvc-710dcb66-fc67-11e8-a606-080027ba45e5   100Gi      RWO            Delete           Bound     default/datadir-my-release-cockroachdb-2   standard                 11m

Tip:

The StatefulSet configuration sets all CockroachDB nodes to log to `stderr`, so if you ever need access to a pod/node's logs to troubleshoot, use `kubectl logs <podname>` rather than checking the log on the persistent volume.

## Step 3. Use the built-in SQL client

To use the built-in SQL client, you need to launch a pod that runs indefinitely with the `cockroach` binary inside it, get a shell into the pod, and then start the built-in SQL client.

~~~ shell $ kubectl create \ -f https://raw.githubusercontent.com/cockroachdb/cockroach/master/cloud/kubernetes/bring-your-own-certs/client.yaml ~~~

Note:
The pod uses the `root` client certificate created earlier to initialize the cluster, so there's no CSR approval required. If you issue client certificates for other users, however, be sure your SQL usernames contain only lowercase alphanumeric characters, `-`, or `.` so as to comply with CSR naming requirements.

~~~ pod/cockroachdb-client-secure created ~~~

1. Get a shell into the pod and start the CockroachDB built-in SQL client:

       $ kubectl exec -it cockroachdb-client-secure \
       -- ./cockroach sql \
       --certs-dir=/cockroach-certs \
       --host=cockroachdb-public

       # Welcome to the CockroachDB SQL shell.
       # All statements must be terminated by a semicolon.
       # To exit, type: \q.
       #
       # Server version: CockroachDB CCL v20.1.0 (x86_64-unknown-linux-gnu, built 2020/07/29 22:56:36, go1.13.9) (same version as client)
       # Cluster ID: f82abd88-5d44-4493-9558-d6c75a3b80cc
       #
       # Enter \? for a brief introduction.
       #
       root@:26257/defaultdb>

2. Run some basic CockroachDB SQL statements:

       > CREATE DATABASE bank;

       > CREATE TABLE bank.accounts (id INT PRIMARY KEY, balance DECIMAL);

       > INSERT INTO bank.accounts VALUES (1, 1000.50);

       > SELECT * FROM bank.accounts;

         id | balance
       +----+---------+
          1 | 1000.50
       (1 row)

3. Create a user with a password:

       > CREATE USER roach WITH PASSWORD 'Q7gc8rEdS';

   You will need this username and password to access the Admin UI later.

4. Exit the SQL shell and pod:

       > \q

1. From your local workstation, use our `client-secure.yaml` file to launch a pod and keep it running indefinitely.

   1. Download the file:

          $ curl -OOOOOOOOO \
          https://raw.githubusercontent.com/cockroachdb/cockroach/master/cloud/kubernetes/client-secure.yaml

   2. In the file, change `serviceAccountName: cockroachdb` to `serviceAccountName: my-release-cockroachdb`.

   3. Use the file to launch a pod and keep it running indefinitely:

          $ kubectl create -f client-secure.yaml

          pod "cockroachdb-client-secure" created

      Note:

      The pod uses the `root` client certificate created earlier to initialize the cluster, so there's no CSR approval required. If you issue client certificates for other users, however, be sure your SQL usernames contain only lowercase alphanumeric characters, `-`, or `.` so as to comply with CSR naming requirements.

2. Get a shell into the pod and start the CockroachDB built-in SQL client:

       $ kubectl exec -it cockroachdb-client-secure \
       -- ./cockroach sql \
       --certs-dir=/cockroach-certs \
       --host=my-release-cockroachdb-public

       # Welcome to the CockroachDB SQL shell.
       # All statements must be terminated by a semicolon.
       # To exit, type: \q.
       #
       # Server version: CockroachDB CCL v20.1.0 (x86_64-unknown-linux-gnu, built 2020/07/29 22:56:36, go1.13.9) (same version as client)
       # Cluster ID: f82abd88-5d44-4493-9558-d6c75a3b80cc
       #
       # Enter \? for a brief introduction.
       #
       root@:26257/defaultdb>

3. Run some basic CockroachDB SQL statements:

       > CREATE DATABASE bank;

       > CREATE TABLE bank.accounts (id INT PRIMARY KEY, balance DECIMAL);

       > INSERT INTO bank.accounts VALUES (1, 1000.50);

       > SELECT * FROM bank.accounts;

         id | balance
       +----+---------+
          1 | 1000.50
       (1 row)

4. Create a user with a password:

       > CREATE USER roach WITH PASSWORD 'Q7gc8rEdS';

   You will need this username and password to access the Admin UI later.

5. Exit the SQL shell and pod:

       > \q

Tip:

This pod will continue running indefinitely, so any time you need to reopen the built-in SQL client or run any other `cockroach` client commands (e.g., `cockroach node`), repeat step 2 using the appropriate `cockroach` command.

If you'd prefer to delete the pod and recreate it when needed, run `kubectl delete pod cockroachdb-client-secure`.

## Step 4. Access the Admin UI

To access the cluster's Admin UI:

1. On secure clusters, certain pages of the Admin UI can only be accessed by `admin` users.

   Get a shell into the pod and start the CockroachDB built-in SQL client:

       $ kubectl exec -it cockroachdb-client-secure \
       -- ./cockroach sql \
       --certs-dir=/cockroach-certs \
       --host=cockroachdb-public

2. Assign `roach` to the `admin` role (you only need to do this once):

       > GRANT admin TO roach;

3. Exit the SQL shell and pod:

       > \q

4. In a new terminal window, port-forward from your local machine to the `cockroachdb-public` service:

       $ kubectl port-forward service/cockroachdb-public 8080

       $ kubectl port-forward service/my-release-cockroachdb-public 8080

       Forwarding from 127.0.0.1:8080 -> 8080

   Note:
   The `port-forward` command must be run on the same machine as the web browser in which you want to view the Admin UI. If you have been running these commands from a cloud instance or other non-local shell, you will not be able to view the UI without configuring `kubectl` locally and running the above `port-forward` command on your local machine.

5. Go to https://localhost:8080 and log in with the username and password you created earlier.

   Note:

   If you are using Google Chrome, and you are getting an error about not being able to reach `localhost` because its certificate has been revoked, go to chrome://flags/#allow-insecure-localhost, enable "Allow invalid certificates for resources loaded from localhost", and then restart the browser. Enabling this Chrome feature degrades security for all sites running on `localhost`, not just CockroachDB's Admin UI, so be sure to enable the feature only temporarily.

6. In the UI, verify that the cluster is running as expected:

   - Click View nodes list on the right to ensure that all nodes successfully joined the cluster.
   - Click the Databases tab on the left to verify that `bank` is listed.

## Step 5. Simulate node failure

Based on the `replicas: 3` line in the StatefulSet configuration, Kubernetes ensures that three pods/nodes are running at all times. When a pod/node fails, Kubernetes automatically creates another pod/node with the same network identity and persistent storage.

To see this in action:

1. Terminate one of the CockroachDB nodes:

       $ kubectl delete pod cockroachdb-2

       pod "cockroachdb-2" deleted

       $ kubectl delete pod my-release-cockroachdb-2

       pod "my-release-cockroachdb-2" deleted

2. In the Admin UI, the Cluster Overview will soon show one node as Suspect. As Kubernetes auto-restarts the node, watch how the node once again becomes healthy.

3. Back in the terminal, verify that the pod was automatically restarted:

       $ kubectl get pod cockroachdb-2

       NAME            READY     STATUS    RESTARTS   AGE
       cockroachdb-2   1/1       Running   0          12s

       $ kubectl get pod my-release-cockroachdb-2

       NAME                       READY     STATUS    RESTARTS   AGE
       my-release-cockroachdb-2   1/1       Running   0          44s

## Step 6. Add nodes

1. Add a pod for another CockroachDB node:

       $ kubectl scale statefulset cockroachdb --replicas=4

       statefulset.apps/cockroachdb scaled

       $ helm upgrade \
       my-release \
       cockroachdb/cockroachdb \
       --set statefulset.replicas=4 \
       --reuse-values

       statefulset "my-release-cockroachdb" scaled

2. Get the name of the `Pending` CSR for the new pod:

       $ kubectl get csr

       NAME                         AGE       REQUESTOR                                   CONDITION
       default.client.root          8m        system:serviceaccount:default:cockroachdb   Approved,Issued
       default.node.cockroachdb-0   22m       system:serviceaccount:default:cockroachdb   Approved,Issued
       default.node.cockroachdb-1   22m       system:serviceaccount:default:cockroachdb   Approved,Issued
       default.node.cockroachdb-2   22m       system:serviceaccount:default:cockroachdb   Approved,Issued
       default.node.cockroachdb-3   2m        system:serviceaccount:default:cockroachdb   Pending

       NAME                                    AGE   REQUESTOR                                              CONDITION
       default.client.root                     8m    system:serviceaccount:default:my-release-cockroachdb   Approved,Issued
       default.node.my-release-cockroachdb-0   22m   system:serviceaccount:default:my-release-cockroachdb   Approved,Issued
       default.node.my-release-cockroachdb-1   22m   system:serviceaccount:default:my-release-cockroachdb   Approved,Issued
       default.node.my-release-cockroachdb-2   22m   system:serviceaccount:default:my-release-cockroachdb   Approved,Issued
       default.node.my-release-cockroachdb-3   2m    system:serviceaccount:default:my-release-cockroachdb   Pending

3. Approve the CSR for the new pod:

       $ kubectl certificate approve default.node.cockroachdb-3

       certificatesigningrequest.certificates.k8s.io/default.node.cockroachdb-3 approved

       $ kubectl certificate approve default.node.my-release-cockroachdb-3

       certificatesigningrequest.certificates.k8s.io/default.node.my-release-cockroachdb-3 approved

4. Confirm that pod for the fourth node, `cockroachdb-3`, is `Running` successfully:

       $ kubectl get pods

       NAME                         READY     STATUS    RESTARTS   AGE
       cockroachdb-0                1/1       Running   0          28m
       cockroachdb-1                1/1       Running   0          27m
       cockroachdb-2                1/1       Running   0          10m
       cockroachdb-3                1/1       Running   0          5s
       cockroachdb-client-secure    1/1       Running   0          25m

       NAME                                 READY     STATUS    RESTARTS   AGE
       my-release-cockroachdb-0             1/1       Running   0          28m
       my-release-cockroachdb-1             1/1       Running   0          27m
       my-release-cockroachdb-2             1/1       Running   0          10m
       my-release-cockroachdb-3             1/1       Running   0          5s
       example-545f866f5-2gsrs              1/1       Running   0          25m

## Step 7. Remove nodes

To safely remove a node from your cluster, you must first decommission the node and only then adjust the `spec.replicas` value of your StatefulSet configuration to permanently remove it. This sequence is important because the decommissioning process lets a node finish in-flight requests, rejects any new requests, and transfers all range replicas and range leases off the node.

Warning:

If you remove nodes without first telling CockroachDB to decommission them, you may cause data or even cluster unavailability. For more details about how this works and what to consider before removing nodes, see Decommission Nodes.

1. Get a shell into the `cockroachdb-client-secure` pod you created earlier and use the `cockroach node status` command to get the internal IDs of nodes:

       $ kubectl exec -it cockroachdb-client-secure \
       -- ./cockroach node status \
       --certs-dir=/cockroach-certs \
       --host=cockroachdb-public

         id |               address                                     | build  |            started_at            |            updated_at            | is_available | is_live
       +----+---------------------------------------------------------------------------------+--------+----------------------------------+----------------------------------+--------------+---------+
          1 | cockroachdb-0.cockroachdb.default.svc.cluster.local:26257 | v20.1.17 | 2018-11-29 16:04:36.486082+00:00 | 2018-11-29 18:24:24.587454+00:00 | true         | true
          2 | cockroachdb-2.cockroachdb.default.svc.cluster.local:26257 | v20.1.17 | 2018-11-29 16:55:03.880406+00:00 | 2018-11-29 18:24:23.469302+00:00 | true         | true
          3 | cockroachdb-1.cockroachdb.default.svc.cluster.local:26257 | v20.1.17 | 2018-11-29 16:04:41.383588+00:00 | 2018-11-29 18:24:25.030175+00:00 | true         | true
          4 | cockroachdb-3.cockroachdb.default.svc.cluster.local:26257 | v20.1.17 | 2018-11-29 17:31:19.990784+00:00 | 2018-11-29 18:24:26.041686+00:00 | true         | true
       (4 rows)

       $ kubectl exec -it cockroachdb-client-secure \
       -- ./cockroach node status \
       --certs-dir=/cockroach-certs \
       --host=my-release-cockroachdb-public

         id |                                     address                                     | build  |            started_at            |            updated_at            | is_available | is_live
       +----+---------------------------------------------------------------------------------+--------+----------------------------------+----------------------------------+--------------+---------+
          1 | my-release-cockroachdb-0.my-release-cockroachdb.default.svc.cluster.local:26257 | v20.1.17 | 2018-11-29 16:04:36.486082+00:00 | 2018-11-29 18:24:24.587454+00:00 | true         | true
          2 | my-release-cockroachdb-2.my-release-cockroachdb.default.svc.cluster.local:26257 | v20.1.17 | 2018-11-29 16:55:03.880406+00:00 | 2018-11-29 18:24:23.469302+00:00 | true         | true
          3 | my-release-cockroachdb-1.my-release-cockroachdb.default.svc.cluster.local:26257 | v20.1.17 | 2018-11-29 16:04:41.383588+00:00 | 2018-11-29 18:24:25.030175+00:00 | true         | true
          4 | my-release-cockroachdb-3.my-release-cockroachdb.default.svc.cluster.local:26257 | v20.1.17 | 2018-11-29 17:31:19.990784+00:00 | 2018-11-29 18:24:26.041686+00:00 | true         | true
       (4 rows)

   The pod uses the `root` client certificate created earlier to initialize the cluster, so there's no CSR approval required.

2. Note the ID of the node with the highest number in its address (in this case, the address including `cockroachdb-3`) and use the `cockroach node decommission` command to decommission it:

   Note:

   It's important to decommission the node with the highest number in its address because, when you reduce the replica count, Kubernetes will remove the pod for that node.

       $ kubectl exec -it cockroachdb-client-secure \
       -- ./cockroach node decommission <node ID> \
       --certs-dir=/cockroach-certs \
       --host=cockroachdb-public

       $ kubectl exec -it cockroachdb-client-secure \
       -- ./cockroach node decommission <node ID> \
       --certs-dir=/cockroach-certs \
       --host=my-release-cockroachdb-public

   You'll then see the decommissioning status print to `stderr` as it changes:

        id | is_live | replicas | is_decommissioning | is_draining
       +---+---------+----------+--------------------+-------------+
         4 |  true   |       73 |        true        |    false
       (1 row)

   Once the node has been fully decommissioned and stopped, you'll see a confirmation:

        id | is_live | replicas | is_decommissioning | is_draining
       +---+---------+----------+--------------------+-------------+
         4 |  true   |        0 |        true        |    false
       (1 row)

       No more data reported on target nodes. Please verify cluster health before removing the nodes.

3. Once the node has been decommissioned, remove a pod from your StatefulSet:

       $ kubectl scale statefulset cockroachdb --replicas=3

       statefulset.apps/cockroachdb scaled

       $ helm upgrade \
       my-release \
       cockroachdb/cockroachdb \
       --set statefulset.replicas=3 \
       --reuse-values

## Step 8. Stop the cluster

- If you plan to restart the cluster, use the `minikube stop` command. This shuts down the minikube virtual machine but preserves all the resources you created:

      $ minikube stop

      Stopping local Kubernetes cluster...
      Machine stopped.

  You can restore the cluster to its previous state with `minikube start`.

- If you do not plan to restart the cluster, use the `minikube delete` command. This shuts down and deletes the minikube virtual machine and all the resources you created, including persistent volumes:

      $ minikube delete

      Deleting local Kubernetes cluster...
      Machine deleted.

  Tip:
  To retain logs, copy them from each pod's `stderr` before deleting the cluster and all its resources. To access a pod's standard error stream, run `kubectl logs <podname>`.

## See also

Explore other core CockroachDB benefits and features:

- Replication & Rebalancing
- Fault Tolerance & Recovery
- Low Latency Multi-Region Deployment
- Serializable Transactions
- Cross-Cloud Migration
- Orchestration
- JSON Support

You might also want to learn how to orchestrate a production deployment of CockroachDB with Kubernetes.