Orchestrate a Local Cluster with Kubernetes

On this page

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 free CockroachDB Cloud 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

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.
Start a local Kubernetes cluster:
```
$ minikube start
```

Step 2. Start CockroachDB

Choose a way to deploy and maintain the CockroachDB cluster:

CockroachDB Kubernetes Operator (recommended)
Helm package manager
Manually apply our StatefulSet configuration and related files

Note:

The Operator is currently supported for GKE only.

Install the Operator

Apply the CustomResourceDefinition (CRD) for the Operator:

$ kubectl apply -f https://raw.githubusercontent.com/cockroachdb/cockroach-operator/v2.15.1/install/crds.yaml

customresourcedefinition.apiextensions.k8s.io/crdbclusters.crdb.cockroachlabs.com created

Apply the Operator manifest:

$ kubectl apply -f https://raw.githubusercontent.com/cockroachdb/cockroach-operator/v2.15.1/install/operator.yaml

clusterrole.rbac.authorization.k8s.io/cockroach-operator-role created
serviceaccount/cockroach-operator-default created
clusterrolebinding.rbac.authorization.k8s.io/cockroach-operator-default created
deployment.apps/cockroach-operator created

Validate that the Operator is running:

$ kubectl get pods

NAME                                  READY   STATUS    RESTARTS   AGE
cockroach-operator-6f7b86ffc4-9ppkv   1/1     Running   0          54s

Configure the cluster

On a production cluster, you will need to modify the StatefulSet configuration with values that are appropriate for your workload.

Download and edit example.yaml, which tells the Operator how to configure the Kubernetes cluster.
```
$ curl -O https://raw.githubusercontent.com/cockroachdb/cockroach-operator/v2.15.1/examples/example.yaml
```
```
$ vi example.yaml
```
Allocate CPU and memory resources to CockroachDB on each pod. Enable the commented-out lines in example.yaml and substitute values that are appropriate for your workload. For more context on provisioning CPU and memory, see the Production Checklist.

Tip:

Resource requests and limits should have identical values.
```
  resources:
    requests:
      cpu: "2"
      memory: "8Gi"
    limits:
      cpu: "2"
      memory: "8Gi"
```
Note:

If no resource limits are specified, the pods will be able to consume the maximum available CPUs and memory. However, to avoid overallocating resources when another memory-intensive workload is on the same instance, always set resource requests and limits explicitly.
Modify resources.requests.storage to allocate the appropriate amount of disk storage for your workload. This configuration defaults to 60Gi of disk space per pod. For more context on provisioning storage, see the Production Checklist.
```
resources:
  requests:
    storage: "60Gi"
```

Initialize the cluster

Note:

By default, the Operator will generate and sign 1 client and 1 node certificate to secure the cluster. To authenticate using your own CA, see Operate CockroachDB on Kubernetes.

Apply example.yaml:
```
$ kubectl apply -f example.yaml
```
The Operator will create a StatefulSet and initialize the nodes as a cluster.
```
crdbcluster.crdb.cockroachlabs.com/cockroachdb created
```

Check that the pods were created:

$ kubectl get pods

NAME                                  READY   STATUS    RESTARTS   AGE
cockroach-operator-6f7b86ffc4-9t9zb   1/1     Running   0          3m22s
cockroachdb-0                         1/1     Running   0          2m31s
cockroachdb-1                         1/1     Running   1          102s
cockroachdb-2                         1/1     Running   0          46s

Each pod should have READY status soon after being created.

Set up configuration file

Download and modify our StatefulSet configuration:

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

Allocate CPU and memory resources to CockroachDB on each pod. These settings should be appropriate for your workload. For more context on provisioning CPU and memory, see the Production Checklist.

Tip:

Resource requests and limits should have identical values.
```
resources:
  requests:
    cpu: "2"
    memory: "8Gi"
  limits:
    cpu: "2"
    memory: "8Gi"
```
Note:

If no resource limits are specified, the pods will be able to consume the maximum available CPUs and memory. However, to avoid overallocating resources when another memory-intensive workload is on the same instance, always set resource requests and limits explicitly.
In the volumeClaimTemplates specification, you may want to modify resources.requests.storage for your use case. This configuration defaults to 100Gi of disk space per pod. For more details on customizing disks for performance, see these instructions.
```
resources:
  requests:
    storage: "100Gi"
```

Initialize the cluster

Note:

The below steps use cockroach cert commands to quickly generate and sign the CockroachDB node and client certificates. If you use a different method of generating certificates, make sure to update secret.secretName in the StatefulSet configuration with the name of your node secret.

Create two directories:

$ mkdir certs 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.

Create the CA certificate and key pair:
```
$ cockroach cert create-ca \
--certs-dir=certs \
--ca-key=my-safe-directory/ca.key
```
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
```
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
```

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

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
```

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

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

Initialize the CockroachDB cluster:

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

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

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
```

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

Warning:

The CockroachDB Helm chart is undergoing maintenance for compatibility with Kubernetes versions 1.17 through 1.21 (the latest version as of this writing). No new feature development is currently planned. For new production and local deployments, we currently recommend using a manual configuration (Configs option). If you are experiencing issues with a Helm deployment on production, contact our Support team.

Note:

Secure CockroachDB deployments on Amazon EKS via Helm are not yet supported.

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
```
Update your Helm chart repositories to ensure that you're using the latest CockroachDB chart:
```
$ helm repo update
```
On a production cluster, you will need to modify the StatefulSet configuration with values that are appropriate for your workload. Modify our Helm chart's values.yaml parameters:

Create a my-values.yaml file to override the defaults in values.yaml, substituting your own values in this example based on the guidelines below.

Tip:

Resource requests and limits should have identical values.
```
statefulset:
  resources:
    limits:
      cpu: "16"
      memory: "8Gi"
    requests:
      cpu: "16"
      memory: "8Gi"
conf:
  cache: "2Gi"
  max-sql-memory: "2Gi"
tls:
  enabled: true
```
1. To avoid running out of memory when CockroachDB is not the only pod on a Kubernetes node, you must set memory limits explicitly. This is because CockroachDB does not detect the amount of memory allocated to its pod when run in Kubernetes. We recommend setting conf.cache and conf.max-sql-memory each to 1/4 of the memory allocation specified in statefulset.resources.requests and statefulset.resources.limits.
  
  Tip:
  
  For example, if you are allocating 8Gi of memory to each CockroachDB node, allocate 2Gi to cache and 2Gi to max-sql-memory.
2. You may want to modify storage.persistentVolume.size and storage.persistentVolume.storageClass for your use case. This chart defaults to 100Gi of disk space per pod. For more details on customizing disks for performance, see these instructions.
3. For a secure deployment, set tls.enabled to true.
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.
```
$ 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.

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.

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.

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>

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

Repeat steps 2 and 3 for the other 2 pods.

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

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
```

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

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

Get a shell into one of the pods and start the CockroachDB built-in SQL client:

$ kubectl exec -it cockroachdb-2 \
-- ./cockroach sql \
--certs-dir cockroach-certs

# Welcome to the CockroachDB SQL shell.
# All statements must be terminated by a semicolon.
# To exit, type: \q.
#
# Server version: CockroachDB CCL v20.2.0 (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>

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)
```
Create a user with a password:
```
> CREATE USER roach WITH PASSWORD 'Q7gc8rEdS';
```
You will need this username and password to access the DB Console later.
Exit the SQL shell and pod:
```
> \q
```

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 ~~~

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

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 v20.2.0 (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>

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.

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)
```
Create a user with a password:
```
> CREATE USER roach WITH PASSWORD 'Q7gc8rEdS';
```
You will need this username and password to access the DB Console later.
Exit the SQL shell and pod:
```
> \q
```

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.

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
```

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 v20.2.0 (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>

Tip:

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

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)
```
Create a user with a password:
```
> CREATE USER roach WITH PASSWORD 'Q7gc8rEdS';
```
You will need this username and password to access the DB Console later.
Exit the SQL shell and pod:
```
> \q
```

Step 4. Access the DB Console

To access the cluster's DB Console:

On secure clusters, certain pages of the DB Console 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-2 \
-- ./cockroach sql \
--certs-dir cockroach-certs
```
```
$ kubectl exec -it cockroachdb-client-secure \
-- ./cockroach sql \
--certs-dir=/cockroach-certs \
--host=cockroachdb-public
```
$ kubectl exec -it cockroachdb-client-secure \ -- ./cockroach sql \ --certs-dir=/cockroach-certs \ --host=my-release-cockroachdb-public
Assign roach to the admin role (you only need to do this once):
```
> GRANT admin TO roach;
```
Exit the SQL shell and pod:
```
> \q
```
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/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 DB Console. 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.
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 DB Console, so be sure to enable the feature only temporarily.
In the UI, verify that the cluster is running as expected:
- View the Node List 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:

Terminate one of the CockroachDB nodes:

$ kubectl delete pod cockroachdb-2

pod "cockroachdb-2" deleted

$ kubectl delete pod cockroachdb-2

pod "cockroachdb-2" deleted

$ kubectl delete pod my-release-cockroachdb-2

pod "my-release-cockroachdb-2" deleted

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

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 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

Your Kubernetes cluster includes 3 worker nodes, or instances, that can run pods. A CockroachDB node runs in each pod. As recommended in our production best practices, you should ensure that two pods are not placed on the same worker node.

Open and edit example.yaml.
```
$ vi example.yaml
```
In example.yaml, update the number of nodes:
```
nodes: 4
```
Note:

Note that you must scale by updating the nodes value in the Operator configuration. Using kubectl scale statefulset <cluster-name> --replicas=4 will result in new pods immediately being terminated.
Apply example.yaml with the new configuration:
```
$ kubectl apply -f example.yaml
```

Verify that the new pod started successfully:

$ kubectl get pods

NAME                        READY     STATUS    RESTARTS   AGE
cockroachdb-0               1/1       Running   0          51m
cockroachdb-1               1/1       Running   0          47m
cockroachdb-2               1/1       Running   0          3m
cockroachdb-3               1/1       Running   0          1m
...

Back in the DB Console, view the Node List to ensure that the fourth node successfully joined the cluster.

On a production deployment, first add a worker node, bringing the total from 3 to 4:
- On GKE, resize your cluster.
- On EKS, resize your Worker Node Group.
- On GCE, resize your Managed Instance Group.
- On AWS, resize your Auto Scaling Group.
Edit your StatefulSet configuration to add another pod for the new CockroachDB node:
```
$ kubectl scale statefulset cockroachdb --replicas=4
```
```
statefulset.apps/cockroachdb scaled
```

Verify that the new pod started successfully:

$ kubectl get pods

NAME                        READY     STATUS    RESTARTS   AGE
cockroachdb-0               1/1       Running   0          51m
cockroachdb-1               1/1       Running   0          47m
cockroachdb-2               1/1       Running   0          3m
cockroachdb-3               1/1       Running   0          1m
cockroachdb-client-secure   1/1       Running   0          15m
...

Back in the DB Console, view the Node List to ensure that the fourth node successfully joined the cluster.

Edit your StatefulSet configuration to add another pod for the new CockroachDB node:

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

Release "my-release" has been upgraded. Happy Helming!
LAST DEPLOYED: Tue May 14 14:06:43 2019
NAMESPACE: default
STATUS: DEPLOYED

RESOURCES:
==> v1beta1/PodDisruptionBudget
NAME                           AGE
my-release-cockroachdb-budget  51m

==> v1/Pod(related)

NAME                               READY  STATUS     RESTARTS  AGE
my-release-cockroachdb-0           1/1    Running    0         38m
my-release-cockroachdb-1           1/1    Running    0         39m
my-release-cockroachdb-2           1/1    Running    0         39m
my-release-cockroachdb-3           0/1    Pending    0         0s
my-release-cockroachdb-init-nwjkh  0/1    Completed  0         39m

...

Get the name of the Pending CSR for the new pod:

$ kubectl get csr

NAME                                                   AGE       REQUESTOR                               CONDITION
default.client.root                                    1h        system:serviceaccount:default:default   Approved,Issued
default.node.my-release-cockroachdb-0                  1h        system:serviceaccount:default:default   Approved,Issued
default.node.my-release-cockroachdb-1                  1h        system:serviceaccount:default:default   Approved,Issued
default.node.my-release-cockroachdb-2                  1h        system:serviceaccount:default:default   Approved,Issued
default.node.my-release-cockroachdb-3                  2m        system:serviceaccount:default:default   Pending
node-csr-0Xmb4UTVAWMEnUeGbW4KX1oL4XV_LADpkwjrPtQjlZ4   1h        kubelet                                 Approved,Issued
node-csr-NiN8oDsLhxn0uwLTWa0RWpMUgJYnwcFxB984mwjjYsY   1h        kubelet                                 Approved,Issued
node-csr-aU78SxyU69pDK57aj6txnevr7X-8M3XgX9mTK0Hso6o   1h        kubelet                                 Approved,Issued
...

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

Examine the CSR for the new pod:

$ kubectl describe csr default.node.my-release-cockroachdb-3

Name:               default.node.my-release-cockroachdb-3
Labels:             <none>
Annotations:        <none>
CreationTimestamp:  Thu, 09 Nov 2017 13:39:37 -0500
Requesting User:    system:serviceaccount:default:default
Status:             Pending
Subject:
  Common Name:    node
  Serial Number:
  Organization:   Cockroach
Subject Alternative Names:
         DNS Names:     localhost
                        my-release-cockroachdb-1.my-release-cockroachdb.default.svc.cluster.local
                        my-release-cockroachdb-1.my-release-cockroachdb
                        my-release-cockroachdb-public
                        my-release-cockroachdb-public.default.svc.cluster.local
         IP Addresses:  127.0.0.1
                        10.48.1.6
Events:  <none>

If everything looks correct, approve the CSR for the new pod:

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

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

Verify that the new pod started successfully:

$ kubectl get pods

NAME                        READY     STATUS    RESTARTS   AGE
my-release-cockroachdb-0    1/1       Running   0          51m
my-release-cockroachdb-1    1/1       Running   0          47m
my-release-cockroachdb-2    1/1       Running   0          3m
my-release-cockroachdb-3    1/1       Running   0          1m
cockroachdb-client-secure   1/1       Running   0          15m
...

Back in the DB Console, view the Node List to ensure that the fourth node successfully joined the cluster.

Step 7. Remove nodes

Before removing a node from your cluster, you must first decommission the node. This 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.

Warning:

Do not scale down to fewer than 3 nodes. This is considered an anti-pattern on CockroachDB and will cause errors.

Get a shell into one of the pods and use the cockroach node status command to get the internal IDs of nodes:

$ kubectl exec -it cockroachdb-2 \
-- ./cockroach node status \
--certs-dir cockroach-certs

  id |                 address                 |               sql_address               |  build  |            started_at            |            updated_at            | locality | is_available | is_live
-----+-----------------------------------------+-----------------------------------------+---------+----------------------------------+----------------------------------+----------+--------------+----------
   1 | cockroachdb-0.cockroachdb.default:26257 | cockroachdb-0.cockroachdb.default:26257 | v20.1.4 | 2020-10-22 23:02:10.084425+00:00 | 2020-10-27 20:18:22.117115+00:00 |          | true         | true
   2 | cockroachdb-1.cockroachdb.default:26257 | cockroachdb-1.cockroachdb.default:26257 | v20.1.4 | 2020-10-22 23:02:46.533911+00:00 | 2020-10-27 20:18:22.558333+00:00 |          | true         | true
   3 | cockroachdb-2.cockroachdb.default:26257 | cockroachdb-2.cockroachdb.default:26257 | v20.1.4 | 2020-10-26 21:46:38.90803+00:00  | 2020-10-27 20:18:22.601021+00:00 |          | true         | true
   4 | cockroachdb-3.cockroachdb.default:26257 | cockroachdb-3.cockroachdb.default:26257 | v20.1.4 | 2020-10-27 19:54:04.714241+00:00 | 2020-10-27 20:18:22.74559+00:00  |          | true         | true
(4 rows)

Use the cockroach node decommission command to decommission the node with the highest number in its address (in this case, the address including cockroachdb-3):

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-3 \
-- ./cockroach node decommission \
--self \
--certs-dir cockroach-certs \
--host=<address of node to decommission>

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.

Once the node has been decommissioned, open and edit example.yaml.
```
$ vi example.yaml
```
In example.yaml, update the number of nodes:
```
nodes: 3
```
Apply example.yaml with the new configuration:
```
$ kubectl apply -f example.yaml
```
The Operator will remove the node with the highest number in its address (in this case, the address including cockroachdb-3) from the cluster. It will also remove the persistent volume that was mounted to the pod.

Verify that the pod was successfully removed:

$ kubectl get pods

NAME                        READY     STATUS    RESTARTS   AGE
cockroachdb-0               1/1       Running   0          51m
cockroachdb-1               1/1       Running   0          47m
cockroachdb-2               1/1       Running   0          3m
...

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 | v20.2.19 | 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 | v20.2.19 | 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 | v20.2.19 | 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 | v20.2.19 | 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.

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

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.

Once the node has been decommissioned, scale down your StatefulSet:
```
$ kubectl scale statefulset cockroachdb --replicas=3
```
```
statefulset.apps/cockroachdb scaled
```

Verify that the pod was successfully removed:

$ kubectl get pods

NAME                        READY     STATUS    RESTARTS   AGE
cockroachdb-0               1/1       Running   0          51m
cockroachdb-1               1/1       Running   0          47m
cockroachdb-2               1/1       Running   0          3m
cockroachdb-client-secure   1/1       Running   0          15m
...

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=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 | v20.2.19 | 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 | v20.2.19 | 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 | v20.2.19 | 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 | v20.2.19 | 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.

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=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.

Once the node has been decommissioned, scale down your StatefulSet:
```
$ helm upgrade \
my-release \
cockroachdb/cockroachdb \
--set statefulset.replicas=3 \
--reuse-values
```

Verify that the pod was successfully removed:

$ kubectl get pods

NAME                        READY     STATUS    RESTARTS   AGE
my-release-cockroachdb-0    1/1       Running   0          51m
my-release-cockroachdb-1    1/1       Running   0          47m
my-release-cockroachdb-2    1/1       Running   0          3m
cockroachdb-client-secure   1/1       Running   0          15m
...

You should also remove the persistent volume that was mounted to the pod. Get the persistent volume claims for the volumes:

$ kubectl get pvc

NAME                               STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
datadir-my-release-cockroachdb-0   Bound    pvc-75dadd4c-01a1-11ea-b065-42010a8e00cb   100Gi      RWO            standard       17m
datadir-my-release-cockroachdb-1   Bound    pvc-75e143ca-01a1-11ea-b065-42010a8e00cb   100Gi      RWO            standard       17m
datadir-my-release-cockroachdb-2   Bound    pvc-75ef409a-01a1-11ea-b065-42010a8e00cb   100Gi      RWO            standard       17m
datadir-my-release-cockroachdb-3   Bound    pvc-75e561ba-01a1-11ea-b065-42010a8e00cb   100Gi      RWO            standard       17m

Verify that the PVC with the highest number in its name is no longer mounted to a pod:
```
$ kubectl describe pvc datadir-my-release-cockroachdb-3
```
```
Name:          datadir-my-release-cockroachdb-3
...
Mounted By:    <none>
```

Remove the persistent volume by deleting the PVC:

$ kubectl delete pvc datadir-my-release-cockroachdb-3

persistentvolumeclaim "datadir-my-release-cockroachdb-3" deleted

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>.

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Orchestrate a Local Cluster with Kubernetes

Before you begin

Step 1. Start Kubernetes

Step 2. Start CockroachDB

Install the Operator

Configure the cluster

Initialize the cluster

Set up configuration file

Initialize the cluster

Step 3. Use the built-in SQL client

Step 4. Access the DB Console

Step 5. Simulate node failure

Step 6. Add nodes

Step 7. Remove nodes

Step 8. Stop the cluster

See also