StorageClass configuration

The Cassandra database uses dynamically created persistent volumes to store data. For proper database functioning, Apigee requires you to configure a StorageClass definition that is backed by a solid-state drive (SSD).

If you do not currently have SSD configured for Cassandra, this topic explains how to create a new StorageClass that uses SSD and make it the default class. When Cassandra starts, it will use this default StorageClass.

The steps outlined in this topic for StorageClass configuration are only applicable to a new Cassandra installation. If you already have a Cassandra class installed, you must decommission the existing cluster in order to configure the StorageClass definition. Changes to the StorageClass definition of an existing Cassandra cluster after installation are not supported.

Apigee recommends deploying hybrid in two or more regions, in order to decommission and re-install one region while preserving data in the secondary region. Alternatively, you can use a non-CSI hybrid backup to restore data in a single-region installation, after decommissioning and configuring the required StorageClass definition.

Change the default StorageClass

The following steps explain how to create a StorageClass and make it the default class. For more information, see Change the default storage class in the Kubernetes documentation.

  1. Get the name of the current default StorageClass:
    kubectl get sc

    For example:

    kubectl get sc
        NAME                    PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
        premium-rwo             pd.csi.storage.gke.io   Delete          WaitForFirstConsumer   true                   15h
        standard                kubernetes.io/gce-pd    Delete          Immediate              true                   15h
        standard-rwo (default)  pd.csi.storage.gke.io   Delete          WaitForFirstConsumer   true                   15h
      
  2. Describe the StorageClass named standard-rwo. Note that its type is pd-balanced:
    kubectl describe sc standard-rwo

    For example:

    kubectl describe sc standard-rwo
    Name:                  standard-rwo
    IsDefaultClass:        Yes
    Annotations:           components.gke.io/layer=addon,storageclass.kubernetes.io/is-default-class=false
    Provisioner:           pd.csi.storage.gke.io
    Parameters:            type=pd-balanced
    AllowVolumeExpansion:  True
    MountOptions:          <none>
    ReclaimPolicy:         Delete
    VolumeBindingMode:     WaitForFirstConsumer
    Events:                <none>
  3. Create a new file called storageclass.yaml.
  4. Add this code to the file. Note that the name of the new class is apigee-sc. You can use any name you like. Also, note that the storage type is pd-ssd:
    ---
    kind: StorageClass
    apiVersion: storage.k8s.io/v1
    metadata:
      name: "apigee-sc"
    provisioner: pd.csi.storage.gke.io
    parameters:
      type: pd-ssd
      replication-type: none
    volumeBindingMode: WaitForFirstConsumer
    allowVolumeExpansion: true
  5. Apply the new StorageClass to your Kubernetes cluster:
    kubectl apply -f storageclass.yaml
  6. Execute the following two commands to change the default StorageClass:
    kubectl patch storageclass standard-rwo \
      -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'
    kubectl patch storageclass apigee-sc \
      -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'
  7. Execute this command to verify that the new default StorageClass is called apigee-sc:
    kubectl get sc

    For example:

    kubectl get sc
        NAME                  PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
        apigee-sc (default)   pd.csi.storage.gke.io    Delete          WaitForFirstConsumer   true                   14h
        premium-rwo           pd.csi.storage.gke.io   Delete          WaitForFirstConsumer   true                   15h
        standard              kubernetes.io/gce-pd    Delete          Immediate              true                   15h
        standard-rwo          pd.csi.storage.gke.io   Delete          WaitForFirstConsumer   true                   15h
      
  8. Describe both the StorageClass to verify the value of IsDefaultClass.
    kubectl describe sc apigee-sc
        Name:            apigee-sc
        IsDefaultClass:  Yes
        Annotations:     kubectl.kubernetes.io/last-applied-configuration={"allowVolumeExpansion":true,"apiVersion":"storage.k8s.io/v1","kind":"StorageClass","metadata":{"annotations":{},"name":"apigee-sc"},"parameters":{"replication-type":"none","type":"pd-ssd"},"provisioner":"pd.csi.storage.gke.io","volumeBindingMode":"WaitForFirstConsumer"}
        ,storageclass.kubernetes.io/is-default-class=true
        Provisioner:           pd.csi.storage.gke.io
        Parameters:            replication-type=none,type=pd-ssd
        AllowVolumeExpansion:  True
        MountOptions:          
        ReclaimPolicy:         Delete
        VolumeBindingMode:     WaitForFirstConsumer
        Events:                
        
    kubectl describe sc standard-rwo
        Name:                  standard-rwo
        IsDefaultClass:        No
        Annotations:           components.gke.io/layer=addon,storageclass.kubernetes.io/is-default-class=false
        Provisioner:           pd.csi.storage.gke.io
        Parameters:            type=pd-balanced
        AllowVolumeExpansion:  True
        MountOptions:          
        ReclaimPolicy:         Delete
        VolumeBindingMode:     WaitForFirstConsumer
        Events: