Warning:
This version of CockroachDB is no longer supported. For more details, see the Release Support Policy.

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.

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:

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    $ 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.

  1. From your local workstation, use our cockroachdb-statefulset-secure.yaml file to create the StatefulSet that automatically creates 3 pods, each with a CockroachDB node running inside it.

    Download cockroachdb-statefulset-secure.yaml:

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

    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. Specify this amount by adjusting resources.requests.memory and resources.limits.memory in cockroachdb-statefulset-secure.yaml. Their values should be identical.

    We recommend setting cache and max-sql-memory each to 1/4 of your memory allocation. For example, if you are allocating 8Gi of memory to each CockroachDB node, substitute the following values in this line:

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    --cache 2Gi --max-sql-memory 2Gi
    

    Use the file to create the StatefulSet and start the cluster:

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    $ 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
    

    Alternatively, if you'd rather start with a configuration file that has been customized for performance:

    1. Download our performance version of cockroachdb-statefulset-secure.yaml:

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      $ curl -O https://raw.githubusercontent.com/cockroachdb/cockroach/master/cloud/kubernetes/performance/cockroachdb-statefulset-secure.yaml
      
    2. Modify the file wherever there is a TODO comment.

    3. Use the file to create the StatefulSet and start the cluster:

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

  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:

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      $ 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:

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      $ 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:

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      $ 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:

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      $ 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:

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      $ kubectl get persistentvolumes
      
      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:

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      $ 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:

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      $ 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:

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      $ kubectl get job cluster-init-secure
      
      NAME                  COMPLETIONS   DURATION   AGE
      cluster-init-secure   1/1           23s        35s
      
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      $ 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
      
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.

  1. Install the Helm client.

  2. Install the Helm server, known as Tiller.

    In the likely case that your Kubernetes cluster uses RBAC (e.g., if you are using GKE), you first need to create RBAC resources to grant Tiller access to the Kubernetes API:

    1. Create a rbac-config.yaml file to define a role and service account:

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      apiVersion: v1
      kind: ServiceAccount
      metadata:
        name: tiller
        namespace: kube-system
      ---
      apiVersion: rbac.authorization.k8s.io/v1
      kind: ClusterRoleBinding
      metadata:
        name: tiller
      roleRef:
        apiGroup: rbac.authorization.k8s.io
        kind: ClusterRole
        name: cluster-admin
      subjects:
        - kind: ServiceAccount
          name: tiller
          namespace: kube-system
      
    2. Create the service account:

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      $ kubectl create -f rbac-config.yaml
      
      serviceaccount/tiller created
      clusterrolebinding.rbac.authorization.k8s.io/tiller created
      
    3. Start the Helm server and install Tiller:

      Note:

      Tiller does not currently support Kubernetes 1.16.0. The following command includes a workaround to install Tiller for use with 1.16.0.

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      $ helm init --service-account tiller --override spec.selector.matchLabels.'name'='tiller',spec.selector.matchLabels.'app'='helm' --output yaml | sed 's@apiVersion: extensions/v1beta1@apiVersion: apps/v1@' | kubectl apply -f -
      
      deployment.apps/tiller-deploy created
      service/tiller-deploy created
      
  3. Install the CockroachDB Helm chart, providing a "release" name to identify and track this particular deployment of the chart and setting the Secure.Enabled parameter to true:

    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.

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    $ helm install --name my-release --set Secure.Enabled=true,Resources.requests.memory="<your memory allocation>",CacheSize="<your cache size>",MaxSQLMemory="<your SQL memory size>" 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.

    Warning:

    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 CacheSize and MaxSQLMemory each to 1/4 of the memory allocation specified in your Resources.requests.memory parameter. For example, if you are allocating 8GiB of memory to each CockroachDB node, use the following values with the --set flag in the helm install command:

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    Requests.resources.memory="8GiB",CacheSize="2GiB",MaxSQLMemory="2GiB"
    
    Note:

    You can customize your deployment by passing additional configuration parameters to helm install using the --set key=value[,key=value] flag. For a production cluster, you should consider modifying the Storage and StorageClass parameters. This chart defaults to 100 GiB of disk space per pod, but you may want more or less depending on your use case, and the default persistent volume StorageClass in your environment may not be what you want for a database (e.g., on GCE and Azure the default is not SSD).

  4. 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:

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      $ 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:

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      $ 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:

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      $ 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.

  5. Confirm that three pods are Running successfully:

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

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    $ kubectl certificate approve default.client.root
    
    certificatesigningrequest.certificates.k8s.io/default.client.root approved
    
  7. 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:

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

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    $ kubectl get persistentvolumes
    
    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.

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

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

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    $ kubectl exec -it cockroachdb-client-secure \
    -- ./cockroach sql \
    --certs-dir=/cockroach-certs \
    --host=cockroachdb-public
    
    # Welcome to the cockroach SQL interface.
    # All statements must be terminated by a semicolon.
    # To exit: CTRL + D.
    #
    # Client version: CockroachDB CCL v19.1.0 (x86_64-unknown-linux-gnu, built 2019/04/29 18:36:40, go1.11.6)
    # Server version: CockroachDB CCL v19.1.0 (x86_64-unknown-linux-gnu, built 2019/04/29 18:36:40, go1.11.6)
    
    # Cluster ID: 256a8705-e348-4e3a-ab12-e1aba96857e4
    #
    # Enter \? for a brief introduction.
    #
    root@cockroachdb-public:26257/defaultdb>
    
  3. Run some basic CockroachDB SQL statements:

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    > CREATE DATABASE bank;
    
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    > CREATE TABLE bank.accounts (id INT PRIMARY KEY, balance DECIMAL);
    
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    > INSERT INTO bank.accounts VALUES (1, 1000.50);
    
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    > SELECT * FROM bank.accounts;
    
      id | balance
    +----+---------+
       1 | 1000.50
    (1 row)
    
  4. Create a user with a password:

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    > 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:

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    > \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:

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      $ 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:

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      $ 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:

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    $ kubectl exec -it cockroachdb-client-secure \
    -- ./cockroach sql \
    --certs-dir=/cockroach-certs \
    --host=my-release-cockroachdb-public
    
    # Welcome to the cockroach SQL interface.
    # All statements must be terminated by a semicolon.
    # To exit: CTRL + D.
    #
    # Client version: CockroachDB CCL v19.1.0 (x86_64-unknown-linux-gnu, built 2019/04/29 18:36:40, go1.11.6)
    # Server version: CockroachDB CCL v19.1.0 (x86_64-unknown-linux-gnu, built 2019/04/29 18:36:40, go1.11.6)
    
    # Cluster ID: 256a8705-e348-4e3a-ab12-e1aba96857e4
    #
    # Enter \? for a brief introduction.
    #
    root@my-release-cockroachdb-public:26257/defaultdb>
    
  3. Run some basic CockroachDB SQL statements:

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    > CREATE DATABASE bank;
    
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    > CREATE TABLE bank.accounts (id INT PRIMARY KEY, balance DECIMAL);
    
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    > INSERT INTO bank.accounts VALUES (1, 1000.50);
    
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    > SELECT * FROM bank.accounts;
    
      id | balance
    +----+---------+
       1 | 1000.50
    (1 row)
    
  4. Create a user with a password:

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    > 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:

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    > \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:

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    $ 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):

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    > GRANT admin TO roach;
    
  3. Exit the SQL shell and pod:

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    > \q
    
  4. In a new terminal window, port-forward from your local machine to one of the pods:

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    $ kubectl port-forward cockroachdb-0 8080
    
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    $ kubectl port-forward my-release-cockroachdb-0 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:

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    $ kubectl delete pod cockroachdb-2
    
    pod "cockroachdb-2" deleted
    
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    $ 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:

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    $ kubectl get pod cockroachdb-2
    
    NAME            READY     STATUS    RESTARTS   AGE
    cockroachdb-2   1/1       Running   0          12s
    
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    $ 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:

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    $ kubectl scale statefulset cockroachdb --replicas=4
    
    statefulset.apps/cockroachdb scaled
    
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    $ helm upgrade \
    my-release \
    cockroachdb/cockroachdb \
    --set Replicas=4 \
    --reuse-values
    
    statefulset "my-release-cockroachdb" scaled
    
  2. Get the name of the Pending CSR for the new pod:

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    $ 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:

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    $ kubectl certificate approve default.node.cockroachdb-3
    
    certificatesigningrequest.certificates.k8s.io/default.node.cockroachdb-3 approved
    
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    $ 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:

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    $ 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 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:

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    $ 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 | v19.1.11 | 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 | v19.1.11 | 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 | v19.1.11 | 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 | v19.1.11 | 2018-11-29 17:31:19.990784+00:00 | 2018-11-29 18:24:26.041686+00:00 | true         | true
    (4 rows)
    
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    $ 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 | v19.1.11 | 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 | v19.1.11 | 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 | v19.1.11 | 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 | v19.1.11 | 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.

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

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    $ kubectl scale statefulset cockroachdb --replicas=3
    
    statefulset.apps/cockroachdb scaled
    
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    $ helm upgrade \
    my-release \
    cockroachdb/cockroachdb \
    --set 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:

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    $ 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:

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    $ 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:

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



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