Orchestrate CockroachDB in a Single Kubernetes Cluster (Insecure)

This page shows you how to orchestrate the deployment, management, and monitoring of an insecure 3-node CockroachDB cluster in a single Kubernetes cluster, using the StatefulSet feature directly or via the Helm Kubernetes package manager.

To deploy across multiple Kubernetes clusters in different geographic regions instead, see Kubernetes Multi-Cluster Deployment. Also, for details about potential performance bottlenecks to be aware of when running CockroachDB in Kubernetes and guidance on how to optimize your deployment for better performance, see CockroachDB Performance on Kubernetes.

Before you begin

Before getting started, it's helpful to review some Kubernetes-specific terminology and current limitations.

Kubernetes terminology

Feature	Description
instance	A physical or virtual machine. In this tutorial, you'll create GCE or AWS instances and join them into a single Kubernetes cluster from your local workstation.
pod	A pod is a group of one or more Docker containers. In this tutorial, each pod will run on a separate instance and include 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 networked storage (Persistent Disk on GCE, Elastic Block Store on AWS) 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. This tutorial assumes that dynamic volume provisioning is available. When that is not the case, persistent volume claims need to be created manually.

Limitations

Kubernetes version

Kubernetes 1.18 or higher is required in order to use our most up-to-date configuration files. Earlier Kubernetes releases do not support some of the options used in our configuration files. If you need to run on an older version of Kubernetes, we have kept around configuration files that work on older Kubernetes releases in the versioned subdirectories of https://github.com/cockroachdb/cockroach/tree/master/cloud/kubernetes (e.g., v1.7).

Storage

At this time, orchestrations of CockroachDB with Kubernetes use external persistent volumes that are often replicated by the provider. Because CockroachDB already replicates data automatically, this additional layer of replication is unnecessary and can negatively impact performance. High-performance use cases on a private Kubernetes cluster may want to consider using local volumes.

Step 1. Start Kubernetes

Choose whether you want to orchestrate CockroachDB with Kubernetes using the hosted Google Kubernetes Engine (GKE) service or manually on Google Compute Engine (GCE) or AWS. The instructions below will change slightly depending on your choice.

• Hosted GKE
• Manual GCE
• Manual AWS

Hosted GKE

1. Complete the Before You Begin steps described in the Google Kubernetes Engine Quickstart documentation.

   This includes installing gcloud, which is used to create and delete Kubernetes Engine clusters, and kubectl, which is the command-line tool used to manage Kubernetes from your workstation.

   Tip:

   The documentation offers the choice of using Google's Cloud Shell product or using a local shell on your machine. Choose to use a local shell if you want to be able to view the CockroachDB Admin UI using the steps in this guide.

2. From your local workstation, start the Kubernetes cluster:

   $ gcloud container clusters create cockroachdb --machine-type n1-standard-4
   

   Creating cluster cockroachdb...done.
   

   This creates GKE instances and joins them into a single Kubernetes cluster named cockroachdb. The --machine-type flag tells the node pool to use the n1-standard-4 machine type (4 vCPUs, 15 GB memory), which meets our recommended CPU and memory configuration.

   The process can take a few minutes, so do not move on to the next step until you see a Creating cluster cockroachdb...done message and details about your cluster.

3. Get the email address associated with your Google Cloud account:

   $ gcloud info | grep Account
   

   Account: [your.google.cloud.email@example.org]
   

   Warning:

   This command returns your email address in all lowercase. However, in the next step, you must enter the address using the accurate capitalization. For example, if your address is YourName@example.com, you must use YourName@example.com and not yourname@example.com.

4. Create the RBAC roles CockroachDB needs for running on GKE, using the address from the previous step:

   $ kubectl create clusterrolebinding $USER-cluster-admin-binding --clusterrole=cluster-admin --user=<your.google.cloud.email@example.org>
   

   clusterrolebinding "cluster-admin-binding" created
   

Manual GCE

From your local workstation, install prerequisites and start a Kubernetes cluster as described in the Running Kubernetes on Google Compute Engine documentation.

The process includes:

• Creating a Google Cloud Platform account, installing gcloud, and other prerequisites.
• Downloading and installing the latest Kubernetes release.
• Creating GCE instances and joining them into a single Kubernetes cluster.
• Installing kubectl, the command-line tool used to manage Kubernetes from your workstation.

Manual AWS

From your local workstation, install prerequisites and start a Kubernetes cluster as described in the Running Kubernetes on AWS EC2 documentation.

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.yaml file to create the StatefulSet that automatically creates 3 pods, each with a CockroachDB node running inside it:

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

   service "cockroachdb-public" created
   service "cockroachdb" created
   poddisruptionbudget "cockroachdb-budget" created
   statefulset "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-insecure.yaml:

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

   2. Modify the file wherever there is a TODO comment.

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

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

2. 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
   

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

   $ kubectl get persistentvolumes
   

   NAME                                       CAPACITY   ACCESSMODES   RECLAIMPOLICY   STATUS    CLAIM                           REASON    AGE
   pvc-52f51ecf-8bd5-11e6-a4f4-42010a800002   1Gi        RWO           Delete          Bound     default/datadir-cockroachdb-0             26s
   pvc-52fd3a39-8bd5-11e6-a4f4-42010a800002   1Gi        RWO           Delete          Bound     default/datadir-cockroachdb-1             27s
   pvc-5315efda-8bd5-11e6-a4f4-42010a800002   1Gi        RWO           Delete          Bound     default/datadir-cockroachdb-2             27s
   

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

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

   job "cluster-init" created
   

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

   $ kubectl get job cluster-init
   

   NAME           DESIRED   SUCCESSFUL   AGE
   cluster-init   1         1            2m
   

   $ 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
   

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 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:

      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:

      $ kubectl create -f rbac-config.yaml
      

      serviceaccount "tiller" created
      clusterrolebinding "tiller" created
      

   3. Start the Helm server:

      $ helm init --service-account tiller
      

3. Install the CockroachDB Helm chart, providing a "release" name to identify and track this particular deployment of the chart:

   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 --name my-release 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.

   Note:

   You can customize your deployment by passing 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. Confirm that three pods are Running successfully:

   $ kubectl get pods
   

   NAME                       READY     STATUS    RESTARTS   AGE
   my-release-cockroachdb-0   1/1       Running   0          48s
   my-release-cockroachdb-1   1/1       Running   0          47s
   my-release-cockroachdb-2   1/1       Running   0          47s
   

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

   $ kubectl get persistentvolumes
   

   NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS    CLAIM                                      STORAGECLASS   REASON    AGE
   pvc-64878ebf-f3f0-11e8-ab5b-42010a8e0035   100Gi      RWO            Delete           Bound     default/datadir-my-release-cockroachdb-0   standard                 51s
   pvc-64945b4f-f3f0-11e8-ab5b-42010a8e0035   100Gi      RWO            Delete           Bound     default/datadir-my-release-cockroachdb-1   standard                 51s
   pvc-649d920d-f3f0-11e8-ab5b-42010a8e0035   100Gi      RWO            Delete           Bound     default/datadir-my-release-cockroachdb-2   standard                 51s
   

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

1. Launch a temporary interactive pod and start the built-in SQL client inside it:

   $ kubectl run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
   -- sql --insecure --host=cockroachdb-public
   

   $ kubectl run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
   -- sql --insecure --host=my-release-cockroachdb-public
   

2. Run some basic CockroachDB SQL statements:

   > CREATE DATABASE bank;
   

   > CREATE TABLE bank.accounts (
       id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
         balance DECIMAL
     );
   

   > INSERT INTO bank.accounts (balance)
     VALUES
         (1000.50), (20000), (380), (500), (55000);
   

   > SELECT * FROM bank.accounts;
   

                      id                  | balance
   +--------------------------------------+---------+
     6f123370-c48c-41ff-b384-2c185590af2b |     380
     990c9148-1ea0-4861-9da7-fd0e65b0a7da | 1000.50
     ac31c671-40bf-4a7b-8bee-452cff8a4026 |     500
     d58afd93-5be9-42ba-b2e2-dc00dcedf409 |   20000
     e6d8f696-87f5-4d3c-a377-8e152fdc27f7 |   55000
   (5 rows)
   

3. Exit the SQL shell and delete the temporary pod:

   > \q
   

Step 4. Access the Admin UI

To access the cluster's Admin UI:

1. Port-forward from your local machine to one of the pods:

   $ kubectl port-forward cockroachdb-0 8080
   

   $ 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.

2. Go to http://localhost:8080.

3. 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. Set up monitoring and alerting

Despite CockroachDB's various built-in safeguards against failure, it is critical to actively monitor the overall health and performance of a cluster running in production and to create alerting rules that promptly send notifications when there are events that require investigation or intervention.

Configure Prometheus

Every node of a CockroachDB cluster exports granular timeseries metrics formatted for easy integration with Prometheus, an open source tool for storing, aggregating, and querying timeseries data. This section shows you how to orchestrate Prometheus as part of your Kubernetes cluster and pull these metrics into Prometheus for external monitoring.

This guidance is based on CoreOS's Prometheus Operator, which allows a Prometheus instance to be managed using built-in Kubernetes concepts.

1. From your local workstation, edit the cockroachdb service to add the prometheus: cockroachdb label:

   $ kubectl label svc cockroachdb prometheus=cockroachdb
   

   service "cockroachdb" labeled
   

   This ensures that there is a prometheus job and monitoring data only for the cockroachdb service, not for the cockroach-public service.

   $ kubectl label svc my-release-cockroachdb prometheus=cockroachdb
   

   service "cockroachdb" labeled
   

   This ensures that there is a prometheus job and monitoring data only for the my-release-cockroachdb service, not for the my-release-cockroach-public service.

2. Install CoreOS's Prometheus Operator:

   $ kubectl apply -f https://raw.githubusercontent.com/coreos/prometheus-operator/release-0.20/bundle.yaml
   

   clusterrolebinding "prometheus-operator" created
   clusterrole "prometheus-operator" created
   serviceaccount "prometheus-operator" created
   deployment "prometheus-operator" created
   

3. Confirm that the prometheus-operator has started:

   $ kubectl get deploy prometheus-operator
   

   NAME                  DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
   prometheus-operator   1         1         1            1           1m
   

4. Use our prometheus.yaml file to create the various objects necessary to run a Prometheus instance:

   $ kubectl apply -f https://raw.githubusercontent.com/cockroachdb/cockroach/master/cloud/kubernetes/prometheus/prometheus.yaml
   

   clusterrole "prometheus" created
   clusterrolebinding "prometheus" created
   servicemonitor "cockroachdb" created
   prometheus "cockroachdb" created
   

5. Access the Prometheus UI locally and verify that CockroachDB is feeding data into Prometheus:

   1. Port-forward from your local machine to the pod running Prometheus:

      $ kubectl port-forward prometheus-cockroachdb-0 9090
      

   2. Go to http://localhost:9090 in your browser.

   3. To verify that each CockroachDB node is connected to Prometheus, go to Status > Targets. The screen should look like this:

      

   4. To verify that data is being collected, go to Graph, enter the sys_uptime variable in the field, click Execute, and then click the Graph tab. The screen should like this:

      

   Tip:

   Prometheus auto-completes CockroachDB time series metrics for you, but if you want to see a full listing, with descriptions, port-forward as described in Access the Admin UI and then point your browser to http://localhost:8080/_status/vars.

   For more details on using the Prometheus UI, see their official documentation.

Configure Alertmanager

Active monitoring helps you spot problems early, but it is also essential to send notifications when there are events that require investigation or intervention. This section shows you how to use Alertmanager and CockroachDB's starter alerting rules to do this.

1. Download our alertmanager-config.yaml configuration file.

2. Edit the alertmanager-config.yaml file to specify the desired receivers for notifications. Initially, the file contains a placeholder web hook.

3. Add this configuration to the Kubernetes cluster as a secret, renaming it to alertmanager.yaml and labelling it to make it easier to find:

   $ kubectl create secret generic alertmanager-cockroachdb --from-file=alertmanager.yaml=alertmanager-config.yaml
   

   secret "alertmanager-cockroachdb" created
   

   $ kubectl label secret alertmanager-cockroachdb app=cockroachdb
   

   secret "alertmanager-cockroachdb" labeled
   

   Warning:

   The name of the secret, alertmanager-cockroachdb, must match the name used in the altermanager.yaml file. If they differ, the Alertmanager instance will start without configuration, and nothing will happen.

4. Use our alertmanager.yaml file to create the various objects necessary to run an Alertmanager instance, including a ClusterIP service so that Prometheus can forward alerts:

   $ kubectl apply -f https://raw.githubusercontent.com/cockroachdb/cockroach/master/cloud/kubernetes/prometheus/alertmanager.yaml
   

   alertmanager "cockroachdb" created
   service "alertmanager-cockroachdb" created
   

5. Verify that Alertmanager is running:

   1. Port-forward from your local machine to the pod running Alertmanager:

      $ kubectl port-forward alertmanager-cockroachdb-0 9093
      

   2. Go to http://localhost:9093 in your browser. The screen should look like this:

      

6. Ensure that the Alertmanagers are visible to Prometheus by opening http://localhost:9090/status. The screen should look like this:

   

7. Add CockroachDB's starter alerting rules:

   $ kubectl apply -f https://raw.githubusercontent.com/cockroachdb/cockroach/master/cloud/kubernetes/prometheus/alert-rules.yaml
   

   prometheusrule "prometheus-cockroachdb-rules" created
   

8. Ensure that the rules are visible to Prometheus by opening http://localhost:9090/rules. The screen should look like this:

   

9. Verify that the example alert is firing by opening http://localhost:9090/alerts. The screen should look like this:

   

10. To remove the example alert:

    1. Use the kubectl edit command to open the rules for editing:

       $ kubectl edit prometheusrules prometheus-cockroachdb-rules
       

    2. Remove the dummy.rules block and save the file:

       - name: rules/dummy.rules
         rules:
         - alert: TestAlertManager
           expr: vector(1)
       

Step 7. Maintain the cluster

Add nodes

The Kubernetes cluster contains 4 nodes, one master and 3 workers. Pods get placed only on worker nodes, so to ensure that you do not have two pods on the same node (as recommended in our production best practices), you need to add a new worker node and then edit your StatefulSet configuration to add another pod. The Kubernetes cluster we created contains 3 nodes that pods can be run on. To ensure that you do not have two pods on the same node (as recommended in our production best practices), you need to add a new node and then edit your StatefulSet configuration to add another pod.

1. Add a worker node:

   • On GKE, resize your cluster.
   • On GCE, resize your Managed Instance Group.
   • On AWS, resize your Auto Scaling Group.

2. Use the kubectl scale command to add a pod to your StatefulSet:

   $ kubectl scale statefulset cockroachdb --replicas=4
   

   statefulset "cockroachdb" scaled
   

   $ kubectl scale statefulset my-release-cockroachdb --replicas=4
   

   statefulset "my-release-cockroachdb" scaled
   

3. Verify that a fourth pod was added successfully:

   $ kubectl get pods
   

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.

1. Launch a temporary interactive pod and use the cockroach node status command to get the internal IDs of nodes:

   $ kubectl run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
   -- node status --insecure --host=cockroachdb-public
   

     id |               address                                     | build  |            started_at            |            updated_at            | is_available | is_live
   +----+---------------------------------------------------------------------------------+--------+----------------------------------+----------------------------------+--------------+---------+
      1 | cockroachdb-0.cockroachdb.default.svc.cluster.local:26257 | v2.1.1 | 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 | v2.1.1 | 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 | v2.1.1 | 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 | v2.1.1 | 2018-11-29 17:31:19.990784+00:00 | 2018-11-29 18:24:26.041686+00:00 | true         | true
   (4 rows)
   

   $ kubectl run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
   -- node status --insecure --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 | v2.1.1 | 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 | v2.1.1 | 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 | v2.1.1 | 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 | v2.1.1 | 2018-11-29 17:31:19.990784+00:00 | 2018-11-29 18:24:26.041686+00:00 | true         | true
   (4 rows)
   

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 run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
   -- node decommission <node ID> --insecure --host=cockroachdb-public
   

   $ kubectl run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
   -- node decommission <node ID> --insecure --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, use the kubectl scale command to remove a pod from your StatefulSet:

   $ kubectl scale statefulset cockroachdb --replicas=3
   

   statefulset "cockroachdb" scaled
   

   $ kubectl scale statefulset my-release-cockroachdb --replicas=3
   

   statefulset "my-release-cockroachdb" scaled
   

Upgrade the cluster

As new versions of CockroachDB are released, it's strongly recommended to upgrade to newer versions in order to pick up bug fixes, performance improvements, and new features. The general CockroachDB upgrade documentation provides best practices for how to prepare for and execute upgrades of CockroachDB clusters, but the mechanism of actually stopping and restarting processes in Kubernetes is somewhat special.

Kubernetes knows how to carry out a safe rolling upgrade process of the CockroachDB nodes. When you tell it to change the Docker image used in the CockroachDB StatefulSet, Kubernetes will go one-by-one, stopping a node, restarting it with the new image, and waiting for it to be ready to receive client requests before moving on to the next one. For more information, see the Kubernetes documentation.

1. Decide how the upgrade will be finalized.

   Note:

   This step is relevant only when upgrading from v2.0.x to v2.1. For upgrades within the v2.1.x series, skip this step.

   By default, after all nodes are running the new version, the upgrade process will be auto-finalized. This will enable certain performance improvements and bug fixes introduced in v2.1. After finalization, however, it will no longer be possible to perform a downgrade to v2.0. In the event of a catastrophic failure or corruption, the only option will be to start a new cluster using the old binary and then restore from one of the backups created prior to performing the upgrade.

   We recommend disabling auto-finalization so you can monitor the stability and performance of the upgraded cluster before finalizing the upgrade:

   1. Launch a temporary interactive pod and start the built-in SQL client inside it:

      $ kubectl run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
      -- sql --insecure --host=cockroachdb-public
      

      $ kubectl run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
      -- sql --insecure --host=my-release-cockroachdb-public
      

   2. Set the cluster.preserve_downgrade_option cluster setting:

      > SET CLUSTER SETTING cluster.preserve_downgrade_option = '2.0';
      

2. Kick off the upgrade process by changing the desired Docker image. To do so, pick the version that you want to upgrade to, then run the following command, replacing "VERSION" with your desired new version:

   $ kubectl patch statefulset cockroachdb --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value":"cockroachdb/cockroach:VERSION"}]'
   

   statefulset "cockroachdb" patched
   

   $ kubectl patch statefulset my-release-cockroachdb --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value":"cockroachdb/cockroach:VERSION"}]'
   

   statefulset "my-release0-cockroachdb" patched
   

3. If you then check the status of your cluster's pods, you should see one of them being restarted:

   $ kubectl get pods
   

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

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

4. This will continue until all of the pods have restarted and are running the new image. To check the image of each pod to determine whether they've all be upgraded, run:

   $ kubectl get pods -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[0].image}{"\n"}'
   

   cockroachdb-0   cockroachdb/cockroach:v2.1.11
   cockroachdb-1   cockroachdb/cockroach:v2.1.11
   cockroachdb-2   cockroachdb/cockroach:v2.1.11
   cockroachdb-3   cockroachdb/cockroach:v2.1.11
   

   my-release-cockroachdb-0    cockroachdb/cockroach:v2.1.11
   my-release-cockroachdb-1    cockroachdb/cockroach:v2.1.11
   my-release-cockroachdb-2    cockroachdb/cockroach:v2.1.11
   my-release-cockroachdb-3    cockroachdb/cockroach:v2.1.11
   

5. Finish the upgrade.

   Note:

   This step is relevant only when upgrading from v2.0.x to v2.1. For upgrades within the v2.1.x series, skip this step.

   If you disabled auto-finalization in step 1 above, monitor the stability and performance of your cluster for as long as you require to feel comfortable with the upgrade (generally at least a day). If during this time you decide to roll back the upgrade, repeat the rolling restart procedure with the old binary.

   Once you are satisfied with the new version, re-enable auto-finalization:

   1. Launch a temporary interactive pod and start the built-in SQL client inside it:

      $ kubectl run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
      -- sql --insecure --host=cockroachdb-public
      

      $ kubectl run cockroachdb -it --image=cockroachdb/cockroach --rm --restart=Never \
      -- sql --insecure --host=my-release-cockroachdb-public
      

   2. Re-enable auto-finalization:

      > RESET CLUSTER SETTING cluster.preserve_downgrade_option;
      

Stop the cluster

To shut down the CockroachDB cluster:

1. Delete all of the resources you created, including the logs and remote persistent volumes:

   $ kubectl delete pods,statefulsets,services,persistentvolumeclaims,persistentvolumes,poddisruptionbudget,jobs,rolebinding,clusterrolebinding,role,clusterrole,serviceaccount,alertmanager,prometheus,prometheusrule,serviceMonitor -l app=cockroachdb
   

   pod "cockroachdb-0" deleted
   pod "cockroachdb-1" deleted
   pod "cockroachdb-2" deleted
   pod "cockroachdb-3" deleted
   service "alertmanager-cockroachdb" deleted
   service "cockroachdb" deleted
   service "cockroachdb-public" deleted
   persistentvolumeclaim "datadir-cockroachdb-0" deleted
   persistentvolumeclaim "datadir-cockroachdb-1" deleted
   persistentvolumeclaim "datadir-cockroachdb-2" deleted
   persistentvolumeclaim "datadir-cockroachdb-3" deleted
   poddisruptionbudget "cockroachdb-budget" deleted
   job "cluster-init" deleted
   clusterrolebinding "prometheus" deleted
   clusterrole "prometheus" deleted
   serviceaccount "prometheus" deleted
   alertmanager "cockroachdb" deleted
   prometheus "cockroachdb" deleted
   prometheusrule "prometheus-cockroachdb-rules" deleted
   servicemonitor "cockroachdb" deleted
   

   $ kubectl delete pods,statefulsets,services,persistentvolumeclaims,persistentvolumes,poddisruptionbudget,jobs,rolebinding,clusterrolebinding,role,clusterrole,serviceaccount,alertmanager,prometheus,prometheusrule,serviceMonitor -l app=my-release-cockroachdb
   

   pod "my-release-cockroachdb-0" deleted
   pod "my-release-cockroachdb-1" deleted
   pod "my-release-cockroachdb-2" deleted
   pod "my-release-cockroachdb-3" deleted
   service "alertmanager-cockroachdb" deleted
   service "my-release-cockroachdb" deleted
   service "my-release-cockroachdb-public" deleted
   persistentvolumeclaim "datadir-my-release-cockroachdb-0" deleted
   persistentvolumeclaim "datadir-my-release-cockroachdb-1" deleted
   persistentvolumeclaim "datadir-my-release-cockroachdb-2" deleted
   persistentvolumeclaim "datadir-my-release-cockroachdb-3" deleted
   poddisruptionbudget "cockroachdb-budget" deleted
   job "cluster-init" deleted
   clusterrolebinding "prometheus" deleted
   clusterrole "prometheus" deleted
   serviceaccount "prometheus" deleted
   alertmanager "cockroachdb" deleted
   prometheus "cockroachdb" deleted
   prometheusrule "prometheus-cockroachdb-rules" deleted
   servicemonitor "cockroachdb" deleted
   

2. Stop Kubernetes:

   • Hosted GKE:

     $ gcloud container clusters delete cockroachdb
     

   • Manual GCE:

     $ cluster/kube-down.sh
     

   • Manual AWS:

     $ cluster/kube-down.sh
     

   Warning:

   If you stop Kubernetes without first deleting the persistent volumes, they will still exist in your cloud project.

See also

• Kubernetes Multi-Cluster Deployment
• Kubernetes Performance Guide
• Production Checklist
• Manual Deployment
• Orchestrated Deployment
• Monitoring and Alerting
• Performance Benchmarking
• Performance Tuning
• Local Deployment