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Update Version of ZooKeeper Ensemble

This guide will show you how to use KubeDB Ops-manager operator to update the version of ZooKeeper Cluster.

Before You Begin

  • At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.

  • Install KubeDB Provisioner and Ops-manager operator in your cluster following the steps here.

  • You should be familiar with the following KubeDB concepts:

To keep everything isolated, we are going to use a separate namespace called demo throughout this tutorial.

$ kubectl create ns demo
namespace/demo created

Note: YAML files used in this tutorial are stored in docs/examples/zookeeper directory of kubedb/docs repository.

Prepare ZooKeeper Ensemble

Now, we are going to deploy a ZooKeeper cluster with version 3.8.3.

Deploy ZooKeeper

In this section, we are going to deploy a ZooKeeper cluster. Then, in the next section we will update the version of the database using ZooKeeperOpsRequest CRD. Below is the YAML of the ZooKeeper CR that we are going to create,

apiVersion: kubedb.com/v1alpha2
kind: ZooKeeper
metadata:
  name: zk-quickstart
  namespace: demo
spec:
  version: "3.8.3"
  adminServerPort: 8080
  replicas: 3
  storage:
    resources:
      requests:
        storage: "1Gi"
    storageClassName: "standard"
    accessModes:
      - ReadWriteOnce
  deletionPolicy: "WipeOut"

Let’s create the ZooKeeper CR we have shown above,

$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/zookeeper/update-version/zookeeper.yaml
zookeeper.kubedb.com/zk-quickstart created

Now, wait until zk-quickstart created has status Ready. i.e,

$ kubectl get zk -n demo                                                                                                                                             
NAME               VERSION    STATUS    AGE
zk-quickstart      3.9.1      Ready     109s

We are now ready to apply the ZooKeeperOpsRequest CR to update this database.

update ZooKeeper Version

Here, we are going to update ZooKeeper cluster from 3.8.3 to 3.9.1.

Create ZooKeeperOpsRequest:

In order to update the version of the cluster, we have to create a ZooKeeperOpsRequest CR with your desired version that is supported by KubeDB. Below is the YAML of the ZooKeeperOpsRequest CR that we are going to create,

apiVersion: ops.kubedb.com/v1alpha1
kind: ZooKeeperOpsRequest
metadata:
  name: upgrade-topology
  namespace: demo
spec:
  databaseRef:
    name: zk-quickstart
  type: UpdateVersion
  updateVersion:
    targetVersion: 3.9.1
  timeout: 5m
  apply: IfReady

Here,

  • spec.databaseRef.name specifies that we are performing operation on zk-quickstart ZooKeeper database.
  • spec.type specifies that we are going to perform UpdateVersion on our database.
  • spec.updateVersion.targetVersion specifies the expected version of the database 3.9.1.
  • Have a look here on the respective sections to understand the readinessCriteria, timeout & apply fields.

Let’s create the ZooKeeperOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/zookeeper/update-version/zk-version-upgrade-ops.yaml
zookeeperopsrequest.ops.kubedb.com/upgrade-topology created

Verify ZooKeeper version updated successfully

If everything goes well, KubeDB Ops-manager operator will update the image of ZooKeeper object and related PetSets and Pods.

Let’s wait for ZooKeeperOpsRequest to be Successful. Run the following command to watch ZooKeeperOpsRequest CR,

$ kubectl get zookeeperopsrequest -n demo
Every 2.0s: kubectl get zookeeperopsrequest -n demo
NAME                TYPE            STATUS       AGE
upgrade-topology    UpdateVersion   Successful   84s

We can see from the above output that the ZooKeeperOpsRequest has succeeded. If we describe the ZooKeeperOpsRequest we will get an overview of the steps that were followed to update the database version.

$ kubectl describe zookeeperopsrequest -n demo upgrade-topology
Name:         upgrade-topology
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         ZooKeeperOpsRequest
Metadata:
  Creation Timestamp:  2024-10-23T10:46:27Z
  Generation:          1
  Resource Version:    1112190
  UID:                 6a1baef3-74cb-4a44-9b8f-f4fa49a4cfca
Spec:
  Apply:  IfReady
  Database Ref:
    Name:   zk-quickstart
  Timeout:  5m
  Type:     UpdateVersion
  Update Version:
    Target Version:  3.9.1
Status:
  Conditions:
    Last Transition Time:  2024-10-23T10:46:27Z
    Message:               Zookeeper ops-request has started to update version
    Observed Generation:   1
    Reason:                UpdateVersion
    Status:                True
    Type:                  UpdateVersion
    Last Transition Time:  2024-10-23T10:46:35Z
    Message:               successfully reconciled the ZooKeeper with updated version
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2024-10-23T10:49:25Z
    Message:               Successfully Restarted ZooKeeper nodes
    Observed Generation:   1
    Reason:                RestartPods
    Status:                True
    Type:                  RestartPods
    Last Transition Time:  2024-10-23T10:46:40Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-0
    Last Transition Time:  2024-10-23T10:46:40Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-0
    Last Transition Time:  2024-10-23T10:46:45Z
    Message:               running pod; ConditionStatus:False
    Observed Generation:   1
    Status:                False
    Type:                  RunningPod
    Last Transition Time:  2024-10-23T10:47:25Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-1
    Last Transition Time:  2024-10-23T10:47:25Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-1
    Last Transition Time:  2024-10-23T10:48:05Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-2
    Last Transition Time:  2024-10-23T10:48:05Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-2
    Last Transition Time:  2024-10-23T10:48:45Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-3
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-3
    Last Transition Time:  2024-10-23T10:48:45Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-3
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-3
    Last Transition Time:  2024-10-23T10:49:25Z
    Message:               Successfully updated ZooKeeper version
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                                    Age    From                         Message
  ----     ------                                                    ----   ----                         -------
  Normal   Starting                                                  10m    KubeDB Ops-manager Operator  Start processing for ZooKeeperOpsRequest: demo/upgrade-topology
  Normal   Starting                                                  10m    KubeDB Ops-manager Operator  Pausing ZooKeeper database: demo/zk-quickstart
  Normal   Successful                                                10m    KubeDB Ops-manager Operator  Successfully paused ZooKeeper database: demo/zk-quickstart for ZooKeeperOpsRequest: upgrade-topology
  Normal   UpdatePetSets                                             10m    KubeDB Ops-manager Operator  successfully reconciled the ZooKeeper with updated version
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-0    10m    KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-0
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-0  10m    KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-0
  Warning  running pod; ConditionStatus:False                        10m    KubeDB Ops-manager Operator  running pod; ConditionStatus:False
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-1    9m25s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-1
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-1  9m25s  KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-1
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-2    8m45s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-2
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-2  8m45s  KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-2
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-3    8m5s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-3
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-3  8m5s   KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-3
  Normal   RestartPods                                               7m25s  KubeDB Ops-manager Operator  Successfully Restarted ZooKeeper nodes
  Normal   Starting                                                  7m25s  KubeDB Ops-manager Operator  Resuming ZooKeeper database: demo/zk-quickstart
  Normal   Successful                                                7m25s  KubeDB Ops-manager Operator 

Now, we are going to verify whether the ZooKeeper and the related PetSets and their Pods have the new version image. Let’s check,

$ kubectl get zk -n demo zk-quickstart -o=jsonpath='{.spec.version}{"\n"}'
3.9.1

$ kubectl get petset -n demo zk-quickstart -o=jsonpath='{.spec.template.spec.containers[0].image}{"\n"}'
ghcr.io/appscode-images/zookeeper:3.9.1@sha256:21365fd1bd55cacd6bf556394d6dcb76ad559ad3767adc304e62db205e4b10b7

$ kubectl get pods -n demo zk-quickstart-0 -o=jsonpath='{.spec.containers[0].image}{"\n"}'
ghcr.io/appscode-images/zookeeper:3.9.1

You can see from above, our ZooKeeper cluster has been updated with the new version. So, the updateVersion process is successfully completed.

Cleaning Up

To clean up the Kubernetes resources created by this tutorial, run:

kubectl delete zk -n demo zk-quickstart
kubectl delete zookeeperopsrequest -n demo upgrade-topology