New to KubeDB? Please start here.

Storage Autoscaling of a Cassandra Cluster

This guide will show you how to use KubeDB to autoscale the storage of a Cassandra 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.
Install KubeDB Community, Enterprise and Autoscaler operator in your cluster following the steps here.
Install Metrics Server from here
Install Prometheus from here
You must have a StorageClass that supports volume expansion.
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

Storage Autoscaling of Cluster Database

At first verify that your cluster has a storage class, that supports volume expansion. Let’s check,

$ kubectl get storageclass
NAME                   PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
local-path (default)   rancher.io/local-path   Delete          WaitForFirstConsumer   false                  6h2m
longhorn (default)     driver.longhorn.io      Delete          Immediate              true                   9m41s
longhorn-static        driver.longhorn.io      Delete          Immediate              true                   9m24s

We can see from the output the longhorn storage class has ALLOWVOLUMEEXPANSION field as true. So, this storage class supports volume expansion. We can use it.

Now, we are going to deploy a Cassandra cluster using a supported version by KubeDB operator. Then we are going to apply CassandraAutoscaler to set up autoscaling.

Deploy Cassandra Cluster

In this section, we are going to deploy a Cassandra cluster with version 3.13.2. Then, in the next section we will set up autoscaling for this database using CassandraAutoscaler CRD. Below is the YAML of the Cassandra CR that we are going to create,

If you want to autoscale Cassandra Standalone, Just remove the spec.Replicas from the below yaml and rest of the steps are same.

apiVersion: kubedb.com/v1alpha2
kind: Cassandra
metadata:

  name: cassandra-autoscale
  namespace: demo
spec:
  version: 5.0.3
  topology:
    rack:
      - name: r0
        replicas: 2
        storage:
          storageClassName:
            longhorn
          accessModes:
            - ReadWriteOnce
          resources:
            requests:
              storage: 600Mi
        storageType: Durable
        podTemplate:
          spec:
            containers:
              - name: cassandra
                resources:
                  limits:
                    memory: 3Gi
                    cpu: 2
                  requests:
                    memory: 1Gi
                    cpu: 1
  deletionPolicy: WipeOut

Let’s create the Cassandra CRO we have shown above,

$ kubectl create -f https://github.com/kubedb/docs/raw/v2025.7.31/docs/guides/examples/cassandra/autoscaling/storage/cassandra-autoscale.yaml
cassandra.kubedb.com/cassandra-autoscale created

Now, wait until cassandra-autoscale has status Ready. i.e,

$ kubectl get cassandra -n demo
NAME                  TYPE                  VERSION   STATUS   AGE
cassandra-autoscale   kubedb.com/v1alpha2   5.0.3     Ready    16m

Let’s check volume size from petset, and from the persistent volume,

$ kubectl get petset -n demo cassandra-autoscale-rack-r0 -o json | jq '.spec.volumeClaimTemplates[0].spec.resources.requests.storage'
"600Mi"


$ kubectl get pv -n demo
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                                                                       STORAGECLASS   VOLUMEATTRIBUTESCLASS   REASON   AGE
pvc-394fefad-d4ad-4dfa-ba11-df96e015da30   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-main-config-volume-cassandra-autoscale-rack-r0-1   longhorn       <unset>                          21m
pvc-86ece3c8-520a-4d41-834e-66108867ca36   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-data-cassandra-autoscale-rack-r0-1                 longhorn       <unset>                          21m
pvc-c35bb138-9f13-4098-b2b0-cc151f013f6d   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-main-config-volume-cassandra-autoscale-rack-r0-0   longhorn       <unset>                          21m
pvc-cc932132-de53-425f-bd31-91af255a47e8   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-data-cassandra-autoscale-rack-r0-0                 longhorn       <unset>                          21m
pvc-cd57fb5f-b2f3-48de-b9d2-03059b05113f   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-nodetool-cassandra-autoscale-rack-r0-1             longhorn       <unset>                          21m
pvc-e550c573-60c7-4ec0-9e01-cf22683c502c   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-nodetool-cassandra-autoscale-rack-r0-0             longhorn       <unset>                          21m

You can see the petset has 600Mi storage, and the capacity of all the persistent volume is also 600Mi.

We are now ready to apply the CassandraAutoscaler CRO to set up storage autoscaling for this database.

Storage Autoscaling

Here, we are going to set up storage autoscaling using a CassandraAutoscaler Object.

Create CassandraAutoscaler Object

In order to set up vertical autoscaling for this replicaset database, we have to create a CassandraAutoscaler CRO with our desired configuration. Below is the YAML of the CassandraAutoscaler object that we are going to create,

apiVersion: autoscaling.kubedb.com/v1alpha1
kind: CassandraAutoscaler
metadata:
  name: cassandra-storage-autoscaler
  namespace: demo
spec:
  databaseRef:
    name: cassandra-autoscale
  storage:
    cassandra:
      trigger: "On"
      usageThreshold: 20
      scalingThreshold: 100
      expansionMode: "Offline"

Here,

spec.databaseRef.name specifies that we are performing vertical scaling operation on cassandra-autoscale database.
spec.storage.cassandra.trigger specifies that storage autoscaling is enabled for this database.
spec.storage.cassandra.usageThreshold specifies storage usage threshold, if storage usage exceeds 20% then storage autoscaling will be triggered.
spec.storage.cassandra.scalingThreshold specifies the scaling threshold. Storage will be scaled to 100% of the current amount.
spec.storage.cassandra.expansionMode specifies the expansion mode of volume expansion cassandraOpsRequest created by cassandraAutoscaler. topolvm-provisioner supports online volume expansion so here expansionMode is set as “Online”.

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

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2025.7.31/docs/examples/cassandra/autoscaling/storage/cassandra-autoscaler-ops.yaml
cassandraautoscaler.autoscaling.kubedb.com/cassandra-storage-autosclaer created

Storage Autoscaling is set up successfully

Let’s check that the cassandraautoscaler resource is created successfully,

$ kubectl get cassandraautoscaler -n demo
NAME                           AGE
cassandra-storage-autoscaler   1m25s

$ kubectl describe cassandraautoscaler cassandra-storage-autoscaler -n demo
Name:         cassandra-storage-autoscaler
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  autoscaling.kubedb.com/v1alpha1
Kind:         CassandraAutoscaler
Metadata:
  Creation Timestamp:  2025-07-15T04:48:26Z
  Generation:          1
  Owner References:
    API Version:           kubedb.com/v1alpha2
    Block Owner Deletion:  true
    Controller:            true
    Kind:                  Cassandra
    Name:                  cassandra-autoscale
    UID:                   ca165d22-0cdd-44c9-8fe6-6691ceccc05b
  Resource Version:        82339
  UID:                     d49df408-a2b8-4f30-a9d4-320ca4351885
Spec:
  Database Ref:
    Name:  cassandra-autoscale
  Ops Request Options:
    Apply:  IfReady
  Storage:
    Cassandra:
      Expansion Mode:  Offline
      Scaling Rules:
        Applies Upto:     
        Threshold:        100pc
      Scaling Threshold:  100
      Trigger:            On
      Usage Threshold:    2
Events:                   <none>

So, the cassandraautoscaler resource is created successfully.

Let’s watch the cassandraopsrequest in the demo namespace to see if any cassandraopsrequest object is created. After some time you’ll see that a cassandraopsrequest of type VolumeExpansion will be created based on the scalingThreshold.

$ kubectl get cassandraopsrequest -n demo
NAME                              TYPE              STATUS        AGE
casops-cassandra-autoscale-xojkua   VolumeExpansion   Progressing   15s

Let’s wait for the ops request to become successful.

$ kubectl get cassandraopsrequest -n demo
NAME                                TYPE              STATUS       AGE
casops-cassandra-autoscale-9ah2rp   VolumeExpansion   Successful   10m

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

$kubectl describe cassandraopsrequest -n demo casops-cassandra-autoscale-9ah2rp 
Name:         casops-cassandra-autoscale-9ah2rp
Namespace:    demo
Labels:       app.kubernetes.io/component=database
              app.kubernetes.io/instance=cassandra-autoscale
              app.kubernetes.io/managed-by=kubedb.com
              app.kubernetes.io/name=cassandras.kubedb.com
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         CassandraOpsRequest
Metadata:
  Creation Timestamp:  2025-07-15T04:54:52Z
  Generation:          1
  Owner References:
    API Version:           autoscaling.kubedb.com/v1alpha1
    Block Owner Deletion:  true
    Controller:            true
    Kind:                  CassandraAutoscaler
    Name:                  cassandra-storage-autoscaler
    UID:                   d49df408-a2b8-4f30-a9d4-320ca4351885
  Resource Version:        85451
  UID:                     6f6d2997-12ea-47d0-b07f-f6820827373e
Spec:
  Apply:  IfReady
  Database Ref:
    Name:  cassandra-autoscale
  Type:    VolumeExpansion
  Volume Expansion:
    Mode:  Offline
    Node:  1203126272
Status:
  Conditions:
    Last Transition Time:  2025-07-15T04:54:52Z
    Message:               Cassandra ops-request has started to expand volume of cassandra nodes.
    Observed Generation:   1
    Reason:                VolumeExpansion
    Status:                True
    Type:                  VolumeExpansion
    Last Transition Time:  2025-07-15T04:55:10Z
    Message:               successfully deleted the petSets with orphan propagation policy
    Observed Generation:   1
    Reason:                OrphanPetSetPods
    Status:                True
    Type:                  OrphanPetSetPods
    Last Transition Time:  2025-07-15T04:55:00Z
    Message:               get petset; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  GetPetset
    Last Transition Time:  2025-07-15T04:55:00Z
    Message:               delete petset; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  DeletePetset
    Last Transition Time:  2025-07-15T05:04:40Z
    Message:               successfully updated node PVC sizes
    Observed Generation:   1
    Reason:                UpdateNodePVCs
    Status:                True
    Type:                  UpdateNodePVCs
    Last Transition Time:  2025-07-15T05:03:50Z
    Message:               get pod; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  GetPod
    Last Transition Time:  2025-07-15T04:55:15Z
    Message:               patch ops request; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  PatchOpsRequest
    Last Transition Time:  2025-07-15T04:55:15Z
    Message:               delete pod; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  DeletePod
    Last Transition Time:  2025-07-15T04:55:50Z
    Message:               get pvc; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  GetPvc
    Last Transition Time:  2025-07-15T04:55:50Z
    Message:               patch pvc; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  PatchPvc
    Last Transition Time:  2025-07-15T05:01:05Z
    Message:               compare storage; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  CompareStorage
    Last Transition Time:  2025-07-15T04:57:50Z
    Message:               create pod; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  CreatePod
    Last Transition Time:  2025-07-15T04:57:55Z
    Message:               running cassandra; ConditionStatus:False
    Observed Generation:   1
    Status:                False
    Type:                  RunningCassandra
    Last Transition Time:  2025-07-15T05:04:48Z
    Message:               successfully reconciled the Cassandra resources
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2025-07-15T05:04:53Z
    Message:               PetSet is recreated
    Observed Generation:   1
    Reason:                ReadyPetSets
    Status:                True
    Type:                  ReadyPetSets
    Last Transition Time:  2025-07-15T05:04:53Z
    Message:               get pet set; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  GetPetSet
    Last Transition Time:  2025-07-15T05:04:53Z
    Message:               Successfully completed volumeExpansion for Cassandra
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                    Age    From                         Message
  ----     ------                                    ----   ----                         -------
  Normal   Starting                                  11m    KubeDB Ops-manager Operator  Start processing for CassandraOpsRequest: demo/casops-cassandra-autoscale-9ah2rp
  Normal   Starting                                  11m    KubeDB Ops-manager Operator  Pausing Cassandra databse: demo/cassandra-autoscale
  Normal   Successful                                11m    KubeDB Ops-manager Operator  Successfully paused Cassandra database: demo/cassandra-autoscale for CassandraOpsRequest: casops-cassandra-autoscale-9ah2rp
  Warning  get petset; ConditionStatus:True          10m    KubeDB Ops-manager Operator  get petset; ConditionStatus:True
  Warning  delete petset; ConditionStatus:True       10m    KubeDB Ops-manager Operator  delete petset; ConditionStatus:True
  Warning  get petset; ConditionStatus:True          10m    KubeDB Ops-manager Operator  get petset; ConditionStatus:True
  Normal   OrphanPetSetPods                          10m    KubeDB Ops-manager Operator  successfully deleted the petSets with orphan propagation policy
  Warning  get pod; ConditionStatus:True             10m    KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  patch ops request; ConditionStatus:True   10m    KubeDB Ops-manager Operator  patch ops request; ConditionStatus:True
  Warning  delete pod; ConditionStatus:True          10m    KubeDB Ops-manager Operator  delete pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:False            10m    KubeDB Ops-manager Operator  get pod; ConditionStatus:False
  Warning  get pod; ConditionStatus:True             10m    KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             10m    KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  patch pvc; ConditionStatus:True           10m    KubeDB Ops-manager Operator  patch pvc; ConditionStatus:True
  Warning  compare storage; ConditionStatus:False    10m    KubeDB Ops-manager Operator  compare storage; ConditionStatus:False
  Warning  get pod; ConditionStatus:True             10m    KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             10m    KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             9m56s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             9m56s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
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  Warning  get pod; ConditionStatus:True             9m36s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
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  Warning  get pvc; ConditionStatus:True             9m16s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             9m11s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
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  Warning  get pod; ConditionStatus:True             9m6s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             9m6s   KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             9m1s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             9m1s   KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             8m56s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             8m56s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
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  Warning  get pod; ConditionStatus:True             8m41s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             8m41s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             8m36s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
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  Warning  get pod; ConditionStatus:True             8m31s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
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  Warning  get pod; ConditionStatus:True             8m26s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             8m26s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             8m21s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             8m21s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             8m16s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
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  Warning  get pod; ConditionStatus:True             8m11s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
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  Warning  get pod; ConditionStatus:True             8m6s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             8m6s   KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  compare storage; ConditionStatus:True     8m6s   KubeDB Ops-manager Operator  compare storage; ConditionStatus:True
  Warning  create pod; ConditionStatus:True          8m6s   KubeDB Ops-manager Operator  create pod; ConditionStatus:True
  Warning  patch ops request; ConditionStatus:True   8m6s   KubeDB Ops-manager Operator  patch ops request; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             8m1s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  running cassandra; ConditionStatus:False  8m1s   KubeDB Ops-manager Operator  running cassandra; ConditionStatus:False
  Warning  get pod; ConditionStatus:True             7m56s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             7m51s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
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  Warning  patch ops request; ConditionStatus:True   7m21s  KubeDB Ops-manager Operator  patch ops request; ConditionStatus:True
  Warning  delete pod; ConditionStatus:True          7m21s  KubeDB Ops-manager Operator  delete pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:False            7m16s  KubeDB Ops-manager Operator  get pod; ConditionStatus:False
  Warning  get pod; ConditionStatus:True             6m46s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             6m46s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  patch pvc; ConditionStatus:True           6m46s  KubeDB Ops-manager Operator  patch pvc; ConditionStatus:True
  Warning  compare storage; ConditionStatus:False    6m46s  KubeDB Ops-manager Operator  compare storage; ConditionStatus:False
  Warning  get pod; ConditionStatus:True             6m41s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             6m41s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             6m36s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
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  Warning  get pod; ConditionStatus:True             6m31s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             6m31s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
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  Warning  get pvc; ConditionStatus:True             5m36s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             5m31s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             5m31s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             5m26s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             5m26s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             5m21s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             5m21s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             5m16s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             5m16s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             5m11s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             5m11s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             5m6s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             5m6s   KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             5m1s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             5m1s   KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m56s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             4m56s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m51s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             4m51s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  compare storage; ConditionStatus:True     4m51s  KubeDB Ops-manager Operator  compare storage; ConditionStatus:True
  Warning  create pod; ConditionStatus:True          4m51s  KubeDB Ops-manager Operator  create pod; ConditionStatus:True
  Warning  patch ops request; ConditionStatus:True   4m51s  KubeDB Ops-manager Operator  patch ops request; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m46s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m41s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m36s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m31s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m26s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m21s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m16s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m11s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             4m6s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  patch ops request; ConditionStatus:True   4m6s   KubeDB Ops-manager Operator  patch ops request; ConditionStatus:True
  Warning  delete pod; ConditionStatus:True          4m6s   KubeDB Ops-manager Operator  delete pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:False            4m1s   KubeDB Ops-manager Operator  get pod; ConditionStatus:False
  Warning  get pod; ConditionStatus:True             3m31s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             3m31s  KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  compare storage; ConditionStatus:True     3m31s  KubeDB Ops-manager Operator  compare storage; ConditionStatus:True
  Warning  create pod; ConditionStatus:True          3m31s  KubeDB Ops-manager Operator  create pod; ConditionStatus:True
  Warning  patch ops request; ConditionStatus:True   3m31s  KubeDB Ops-manager Operator  patch ops request; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             3m26s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             3m21s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             3m16s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             3m11s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             3m6s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             3m1s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             2m56s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             2m51s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             2m46s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             2m41s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  patch ops request; ConditionStatus:True   2m41s  KubeDB Ops-manager Operator  patch ops request; ConditionStatus:True
  Warning  delete pod; ConditionStatus:True          2m41s  KubeDB Ops-manager Operator  delete pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:False            2m36s  KubeDB Ops-manager Operator  get pod; ConditionStatus:False
  Warning  get pod; ConditionStatus:True             2m6s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pvc; ConditionStatus:True             2m6s   KubeDB Ops-manager Operator  get pvc; ConditionStatus:True
  Warning  compare storage; ConditionStatus:True     2m6s   KubeDB Ops-manager Operator  compare storage; ConditionStatus:True
  Warning  create pod; ConditionStatus:True          2m6s   KubeDB Ops-manager Operator  create pod; ConditionStatus:True
  Warning  patch ops request; ConditionStatus:True   2m6s   KubeDB Ops-manager Operator  patch ops request; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             2m1s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             102s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             98s    KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             95s    KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             91s    KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             86s    KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Warning  get pod; ConditionStatus:True             81s    KubeDB Ops-manager Operator  get pod; ConditionStatus:True
  Normal   UpdateNodePVCs                            76s    KubeDB Ops-manager Operator  successfully updated node PVC sizes
  Normal   UpdatePetSets                             68s    KubeDB Ops-manager Operator  successfully reconciled the Cassandra resources
  Warning  get pet set; ConditionStatus:True         63s    KubeDB Ops-manager Operator  get pet set; ConditionStatus:True
  Normal   ReadyPetSets                              63s    KubeDB Ops-manager Operator  PetSet is recreated
  Normal   Starting                                  63s    KubeDB Ops-manager Operator  Resuming Cassandra database: demo/cassandra-autoscale
  Normal   Successful                                63s    KubeDB Ops-manager Operator  Successfully resumed Cassandra database: demo/cassandra-autoscale for CassandraOpsRequest: casops-cassandra-autoscale-9ah2rp

Now, we are going to verify from the Petset, and the Persistent Volume whether the volume of the replicaset database has expanded to meet the desired state, Let’s check,

$ kubectl get petset -n demo cassandra-autoscale-rack-r0 -o json | jq '.spec.volumeClaimTemplates[0].spec.resources.requests.storage'
"1203126272"

$  kubectl get pv -n demo
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                                                                       STORAGECLASS   VOLUMEATTRIBUTESCLASS   REASON   AGE
pvc-394fefad-d4ad-4dfa-ba11-df96e015da30   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-main-config-volume-cassandra-autoscale-rack-r0-1   longhorn       <unset>                          45m
pvc-86ece3c8-520a-4d41-834e-66108867ca36   1148Mi     RWO            Delete           Bound    demo/cassandra-autoscale-data-cassandra-autoscale-rack-r0-1                 longhorn       <unset>                          45m
pvc-c35bb138-9f13-4098-b2b0-cc151f013f6d   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-main-config-volume-cassandra-autoscale-rack-r0-0   longhorn       <unset>                          45m
pvc-cc932132-de53-425f-bd31-91af255a47e8   1148Mi     RWO            Delete           Bound    demo/cassandra-autoscale-data-cassandra-autoscale-rack-r0-0                 longhorn       <unset>                          45m
pvc-cd57fb5f-b2f3-48de-b9d2-03059b05113f   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-nodetool-cassandra-autoscale-rack-r0-1             longhorn       <unset>                          45m
pvc-e550c573-60c7-4ec0-9e01-cf22683c502c   600Mi      RWO            Delete           Bound    demo/cassandra-autoscale-nodetool-cassandra-autoscale-rack-r0-0             longhorn       <unset>                          45m

The above output verifies that we have successfully autoscaled the volume related to data of the cassandra cluster.

Cleaning Up

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

kubectl delete cassandra -n demo cassandra-autoscale
kubectl delete cassandraautoscaler -n demo casops-cassandra-autoscale-xojkua
kubectl delete ns demo

KubeDB

KubeStash New

Stash

KubeVault

Voyager

ConfigSyncer

Guard

RESOURCES

Cassandra

Druid

Elasticsearch

FerretDB

Ignite

Kafka

MariaDB

Memcached

Microsoft SQL Server

MongoDB

MySQL

OpenSearch

PerconaXtraDB

PgBouncer

Pgpool

PostgreSQL

ProxySQL

RabbitMQ

Redis

SingleStore

Solr

Valkey

ZooKeeper