New to KubeDB? Please start here.
Horizontal Scale SingleStore
This guide will show you how to use KubeDB Enterprise operator to scale the cluster of a SingleStore database.
Before You Begin
At first, you need to have a Kubernetes cluster, and the
kubectlcommand-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
KubeDBCommunity and Enterprise operator in your cluster following the steps here.You should be familiar with the following
KubeDBconcepts:
To keep everything isolated, we are going to use a separate namespace called demo throughout this tutorial.
$ kubectl create ns demo
namespace/demo created
Apply Horizontal Scaling on Cluster
Here, we are going to deploy a SingleStore cluster using a supported version by KubeDB operator. Then we are going to apply horizontal scaling on it.
Create SingleStore License Secret
We need SingleStore License to create SingleStore Database. So, Ensure that you have acquired a license and then simply pass the license by secret.
$ kubectl create secret generic -n demo license-secret \
--from-literal=username=license \
--from-literal=password='your-license-set-here'
secret/license-secret created
Deploy SingleStore Cluster
In this section, we are going to deploy a SingleStore cluster. Then, in the next section we will scale the database using SingleStoreOpsRequest CRD. Below is the YAML of the SingleStore CR that we are going to create,
apiVersion: kubedb.com/v1alpha2
kind: Singlestore
metadata:
name: sample-sdb
namespace: demo
spec:
version: "8.7.10"
topology:
aggregator:
replicas: 1
podTemplate:
spec:
containers:
- name: singlestore
resources:
limits:
memory: "2Gi"
cpu: "600m"
requests:
memory: "2Gi"
cpu: "600m"
storage:
storageClassName: "longhorn"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
leaf:
replicas: 2
podTemplate:
spec:
containers:
- name: singlestore
resources:
limits:
memory: "2Gi"
cpu: "600m"
requests:
memory: "2Gi"
cpu: "600m"
storage:
storageClassName: "longhorn"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 10Gi
licenseSecret:
name: license-secret
storageType: Durable
deletionPolicy: WipeOut
Let’s create the SingleStore CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.9.30/docs/guides/singlestore/scaling/horizontal-scaling/cluster/example/sample-sdb.yaml
singlestore.kubedb.com/sample-sdb created
Now, wait until sample-sdb has status Ready. i.e,
$ kubectl get singlestore -n demo
NAME TYPE VERSION STATUS AGE
sample-sdb kubedb.com/v1alpha2 8.7.10 Ready 86s
Let’s check the number of aggreagtor replicas and leaf replicas this database has from the SingleStore object, number of pods the aggregator-petset and leaf-petset have,
$ kubectl get sdb -n demo sample-sdb -o json | jq '.spec.topology.aggregator.replicas'
1
$ kubectl get sdb -n demo sample-sdb -o json | jq '.spec.topology.leaf.replicas'
2
$ kubectl get petset -n demo sample-sdb-aggregator -o=jsonpath='{.spec.replicas}{"\n"}'
1
kubectl get petset -n demo sample-sdb-leaf -o=jsonpath='{.spec.replicas}{"\n"}'
2
We can see from both command that the database has 1 aggregator replicas and 2 leaf replicas in the cluster.
Also, we can verify the replicas of the from an internal memsqlctl command by execing into a replica.
Now let’s connect to a singlestore instance and run a memsqlctl internal command to check the number of replicas,
$ kubectl exec -it -n demo sample-sdb-aggregator-0 -- bash
Defaulted container "singlestore" out of: singlestore, singlestore-coordinator, singlestore-init (init)
[memsql@sample-sdb-aggregator-0 /]$ memsqlctl show-cluster
+---------------------+--------------------------------------------------+------+--------------------+-----------+-----------+--------+--------------------+------------------------------+--------+-------------------+
| Role | Host | Port | Availability Group | Pair Host | Pair Port | State | Opened Connections | Average Roundtrip Latency ms | NodeId | Master Aggregator |
+---------------------+--------------------------------------------------+------+--------------------+-----------+-----------+--------+--------------------+------------------------------+--------+-------------------+
| Leaf | sample-sdb-leaf-0.sample-sdb-pods.demo.svc | 3306 | 1 | null | null | online | 2 | | 2 | |
| Leaf | sample-sdb-leaf-1.sample-sdb-pods.demo.svc | 3306 | 1 | null | null | online | 3 | | 3 | |
| Aggregator (Leader) | sample-sdb-aggregator-0.sample-sdb-pods.demo.svc | 3306 | | null | null | online | 1 | null | 1 | 1 |
+---------------------+--------------------------------------------------+------+--------------------+-----------+-----------+--------+--------------------+------------------------------+--------+-------------------+
We can see from the above output that the cluster has 1 aggregator node and 2 leaf nodes.
We are now ready to apply the SingleStoreOpsRequest CR to scale this database.
Scale Up Replicas
Here, we are going to scale up the replicas of the leaf nodes to meet the desired number of replicas after scaling.
Create SingleStoreOpsRequest
In order to scale up the replicas of the leaf nodes of the database, we have to create a SingleStoreOpsRequest CR with our desired replicas. Below is the YAML of the SingleStoreOpsRequest CR that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: SinglestoreOpsRequest
metadata:
name: sdbops-scale-horizontal-up
namespace: demo
spec:
type: HorizontalScaling
databaseRef:
name: sample-sdb
horizontalScaling:
leaf: 3
Here,
spec.databaseRef.namespecifies that we are performing horizontal scaling operation onsample-sdbdatabase.spec.typespecifies that we are performingHorizontalScalingon our database.spec.horizontalScaling.leafspecifies the desired leaf replicas after scaling.
Let’s create the SingleStoreOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.9.30/docs/guides/singlestore/scaling/horizontal-scaling/cluster/example/sdbops-upscale.yaml
singlestoreopsrequest.ops.kubedb.com/sdbops-scale-horizontal-up created
Verify Cluster replicas scaled up successfully
If everything goes well, KubeDB Enterprise operator will update the replicas of SingleStore object and related PetSets and Pods.
Let’s wait for SingleStoreOpsRequest to be Successful. Run the following command to watch SingleStoreOpsRequest CR,
$ kubectl get singlestoreopsrequest -n demo
NAME TYPE STATUS AGE
sdbops-scale-horizontal-up HorizontalScaling Successful 74s
We can see from the above output that the SingleStoreOpsRequest has succeeded. Now, we are going to verify the number of leaf replicas this database has from the SingleStore object, number of pods the leaf petset have,
$ kubectl get sdb -n demo sample-sdb -o json | jq '.spec.topology.leaf.replicas'
3
$ kubectl get petset -n demo sample-sdb-leaf -o=jsonpath='{.spec.replicas}{"\n"}'
3
Now let’s connect to a singlestore instance and run a memsqlctl internal command to check the number of replicas,
$ kubectl exec -it -n demo sample-sdb-aggregator-0 -- bash
Defaulted container "singlestore" out of: singlestore, singlestore-coordinator, singlestore-init (init)
[memsql@sample-sdb-aggregator-0 /]$ memsqlctl show-cluster
+---------------------+--------------------------------------------------+------+--------------------+-----------+-----------+--------+--------------------+------------------------------+--------+-------------------+
| Role | Host | Port | Availability Group | Pair Host | Pair Port | State | Opened Connections | Average Roundtrip Latency ms | NodeId | Master Aggregator |
+---------------------+--------------------------------------------------+------+--------------------+-----------+-----------+--------+--------------------+------------------------------+--------+-------------------+
| Leaf | sample-sdb-leaf-0.sample-sdb-pods.demo.svc | 3306 | 1 | null | null | online | 2 | | 2 | |
| Leaf | sample-sdb-leaf-1.sample-sdb-pods.demo.svc | 3306 | 1 | null | null | online | 3 | | 3 | |
| Leaf | sample-sdb-leaf-2.sample-sdb-pods.demo.svc | 3306 | 1 | null | null | online | 2 | | 4 | |
| Aggregator (Leader) | sample-sdb-aggregator-0.sample-sdb-pods.demo.svc | 3306 | | null | null | online | 1 | null | 1 | 1 |
+---------------------+--------------------------------------------------+------+--------------------+-----------+-----------+--------+--------------------+------------------------------+--------+-------------------+
From all the above outputs we can see that the leaf replicas of the cluster is 3. That means we have successfully scaled up the leaf replicas of the SingleStore Cluster.
Scale Down Replicas
Here, we are going to scale down the leaf replicas of the cluster to meet the desired number of replicas after scaling.
Create SingleStoreOpsRequest
In order to scale down the cluster of the database, we have to create a SingleStoreOpsRequest CR with our desired replicas. Below is the YAML of the SingleStoreOpsRequest CR that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: SinglestoreOpsRequest
metadata:
name: sdbops-scale-horizontal-down
namespace: demo
spec:
type: HorizontalScaling
databaseRef:
name: sample-sdb
horizontalScaling:
leaf: 2
Here,
spec.databaseRef.namespecifies that we are performing horizontal scaling down operation onsample-sdbdatabase.spec.typespecifies that we are performingHorizontalScalingon our database.spec.horizontalScaling.leafspecifies the desiredleaf replicasafter scaling.
Let’s create the SingleStoreOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.9.30/docs/guides/singlestore/scaling/horizontal-scaling/cluster/example/sdbops-downscale.yaml
singlestoreopsrequest.ops.kubedb.com/sdbops-scale-horizontal-down created
Verify Cluster replicas scaled down successfully
If everything goes well, KubeDB Enterprise operator will update the replicas of SingleStore object and related PetSets and Pods.
Let’s wait for SingleStoreOpsRequest to be Successful. Run the following command to watch SingleStoreOpsRequest CR,
$ kubectl get singlestoreopsrequest -n demo
NAME TYPE STATUS AGE
sdbops-scale-horizontal-down HorizontalScaling Successful 63s
We can see from the above output that the SingleStoreOpsRequest has succeeded. Now, we are going to verify the number of leaf replicas this database has from the SingleStore object, number of pods the leaf petset have,
$ kubectl get sdb -n demo sample-sdb -o json | jq '.spec.topology.leaf.replicas'
2
$ kubectl get petset -n demo sample-sdb-leaf -o=jsonpath='{.spec.replicas}{"\n"}'
2
Now let’s connect to a singlestore instance and run a memsqlctl internal command to check the number of replicas,
$ kubectl exec -it -n demo sample-sdb-aggregator-0 -- bash
Defaulted container "singlestore" out of: singlestore, singlestore-coordinator, singlestore-init (init)
bash: mesqlctl: command not found
[memsql@sample-sdb-aggregator-0 /]$ memsqlctl show-cluster
+---------------------+--------------------------------------------------+------+--------------------+-----------+-----------+--------+--------------------+------------------------------+--------+-------------------+
| Role | Host | Port | Availability Group | Pair Host | Pair Port | State | Opened Connections | Average Roundtrip Latency ms | NodeId | Master Aggregator |
+---------------------+--------------------------------------------------+------+--------------------+-----------+-----------+--------+--------------------+------------------------------+--------+-------------------+
| Leaf | sample-sdb-leaf-0.sample-sdb-pods.demo.svc | 3306 | 1 | null | null | online | 2 | | 2 | |
| Leaf | sample-sdb-leaf-1.sample-sdb-pods.demo.svc | 3306 | 1 | null | null | online | 3 | | 3 | |
| Aggregator (Leader) | sample-sdb-aggregator-0.sample-sdb-pods.demo.svc | 3306 | | null | null | online | 1 | null | 1 | 1 |
+---------------------+--------------------------------------------------+------+--------------------+-----------+-----------+--------+--------------------+------------------------------+--------+-------------------+
From all the above outputs we can see that the leaf replicas of the cluster is 2. That means we have successfully scaled down the leaf replicas of the SingleStore database.
Cleaning Up
To clean up the Kubernetes resources created by this tutorial, run:
$ kubectl delete sdb -n demo sample-sdb
$ kubectl delete singlestoreopsrequest -n demo sdbops-scale-horizontal-up sdbops-scale-horizontal-down