New to KubeDB? Please start here.

Upgrade version of Redis Cluster

This guide will show you how to use KubeDB Enterprise operator to upgrade the version of Redis 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 Community and Enterprise 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/redis directory of kubedb/docs repository.

Prepare Redis Cluster Database

Now, we are going to deploy a Redis cluster database with version 5.0.3-v1.

Deploy Redis cluster :

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

apiVersion: kubedb.com/v1alpha2
kind: Redis
metadata:
  name: redis-cluster
  namespace: demo
spec:
  version: 5.0.3-v1
  mode: Cluster
  cluster:
    master: 3
    replicas: 1
  storageType: Durable
  storage:
    resources:
      requests:
        storage: 1Gi
    storageClassName: "standard"
    accessModes:
    - ReadWriteOnce
  terminationPolicy: WipeOut

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

$ kubectl create -f https://github.com/kubedb/docs/raw/v2021.04.16/docs/examples/redis/upgrading/rd-cluster.yaml
redis.kubedb.com/redis-cluster created

Now, wait until redis-cluster created has status Ready. i.e,

$ kubectl get rd -n demo
NAME              VERSION    STATUS   AGE
redis-cluster     5.0.3-v1   Ready    3m14s

We are now ready to apply the RedisOpsRequest CR to upgrade this database.

Upgrade Redis Version

Here, we are going to upgrade Redis cluster from 5.0.3-v1 to 6.0.6.

Create RedispsRequest:

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

apiVersion: ops.kubedb.com/v1alpha1
kind: RedisOpsRequest
metadata:
  name: upgrade-cluster
  namespace: demo
spec:
  type: Upgrade
  databaseRef:
    name: redis-cluster
  upgrade:
    targetVersion: 6.0.6

Here,

  • spec.databaseRef.name specifies that we are performing operation on redis-cluster Redis database.
  • spec.type specifies that we are going to perform Upgrade on our database.
  • spec.upgrade.targetVersion specifies the expected version of the database 6.0.6.

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

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2021.04.16/docs/examples/redis/upgrading/upgrade-cluster.yaml
redisopsrequest.ops.kubedb.com/upgrade-cluster created

Verify Redis version upgraded successfully :

If everything goes well, KubeDB Enterprise operator will update the image of Redis object and related StatefulSets and Pods.

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

$ watch kubectl get redisopsrequest -n demo
Every 2.0s: kubectl get redisopsrequest -n demo
NAME                    TYPE      STATUS       AGE
upgrade-cluster         Upgrade   Successful   90s

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

$ kubectl describe redisopsrequest -n demo upgrade-cluster
Name:         upgrade-cluster
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         RedisOpsRequest
Metadata:
  Creation Timestamp:  2020-11-26T06:18:15Z
  Generation:          1
  Resource Version:    24726
  Self Link:           /apis/ops.kubedb.com/v1alpha1/namespaces/demo/redisopsrequests/upgrade-cluster
  UID:                 02224da5-4bc9-437b-9bea-34325c867b20
Spec:
  Database Ref:
    Name:  redis-cluster
  Type:    Upgrade
  Upgrade:
    Target Version:  6.0.6
Status:
  Conditions:
    Last Transition Time:  2020-11-26T06:18:15Z
    Message:               RedisOpsRequest: demo/upgrade-cluster is upgrading database
    Observed Generation:   1
    Reason:                Upgrade
    Status:                True
    Type:                  Progressing
    Last Transition Time:  2020-11-26T06:18:15Z
    Message:               Successfully paused Redis: redis-cluster
    Observed Generation:   1
    Reason:                PauseDatabase
    Status:                True
    Type:                  PauseDatabase
    Last Transition Time:  2020-11-26T06:18:16Z
    Message:               Successfully Updated StatefulSets Image
    Observed Generation:   1
    Reason:                UpdateStatefulSetImage
    Status:                True
    Type:                  UpdateStatefulSetImage
    Last Transition Time:  2020-11-26T06:19:21Z
    Message:               Successfully Restarted Pods With Updated Version Image
    Observed Generation:   1
    Reason:                RestartedPodsWithImage
    Status:                True
    Type:                  RestartedPodsWithImage
    Last Transition Time:  2020-11-26T06:19:21Z
    Message:               Upgrading have been done successfully
    Observed Generation:   1
    Reason:                upgradingDone
    Status:                True
    Type:                  upgradingDone
    Last Transition Time:  2020-11-26T06:19:21Z
    Message:               Successfully resumed Redis: redis-cluster
    Observed Generation:   1
    Reason:                ResumeDatabase
    Status:                True
    Type:                  ResumeDatabase
    Last Transition Time:  2020-11-26T06:19:21Z
    Message:               RedisOpsRequest: demo/upgrade-cluster Successfully Upgraded Database
    Observed Generation:   1
    Reason:                Upgrade
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type    Reason                  Age   From                        Message
  ----    ------                  ----  ----                        -------
  Normal  PauseDatabase           2m8s  KubeDB Enterprise Operator  Pausing Redis demo/redis-cluster
  Normal  PauseDatabase           2m8s  KubeDB Enterprise Operator  Successfully paused Redis demo/redis-cluster
  Normal  Starting                2m8s  KubeDB Enterprise Operator  Updating Image of StatefulSet: redis-cluster-shard0
  Normal  Starting                2m8s  KubeDB Enterprise Operator  Updating Image of StatefulSet: redis-cluster-shard1
  Normal  Starting                2m7s  KubeDB Enterprise Operator  Updating Image of StatefulSet: redis-cluster-shard2
  Normal  UpdateStatefulSetImage  2m7s  KubeDB Enterprise Operator  Successfully updated StatefulSets Image
  Normal  RestartedPodsWithImage  62s   KubeDB Enterprise Operator  Successfully Restarted Pods With Updated Version Image
  Normal  ResumeDatabase          62s   KubeDB Enterprise Operator  Pausing Redis demo/redis-cluster
  Normal  ResumeDatabase          62s   KubeDB Enterprise Operator  Successfully resumed Redis demo/redis-cluster
  Normal  Successful              62s   KubeDB Enterprise Operator  Successfully Completed the OpsRequest

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

$ kubectl get redis -n demo redis-cluster -o=jsonpath='{.spec.version}{"\n"}'
6.0.6

$ kubectl get statefulset -n demo redis-cluster-shard0 -o=jsonpath='{.spec.template.spec.containers[0].image}{"\n"}'
kubedb/redis:6.0.6

$ kubectl get pods -n demo redis-cluster-shard1-1 -o=jsonpath='{.spec.containers[0].image}{"\n"}'
kubedb/redis:6.0.6

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

Cleaning Up

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

kubectl delete redis -n demo redis-cluster
kubectl delete redisopsrequest -n demo upgrade-cluster