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.

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

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>

Create a new file called storageclass.yaml.

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

Apply the new StorageClass to your Kubernetes cluster:
```
kubectl apply -f storageclass.yaml
```

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"}}}'

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

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: