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Autoscaling the Compute Resource of a SingleStore Cluster

This guide will show you how to use KubeDB to autoscale compute resources i.e. cpu and memory of a singlestore cluster for aggregator and leaf nodes.

Before You Begin

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/singlestore directory of kubedb/docs repository.

Autoscaling of SingleStore Cluster

Here, we are going to deploy a SingleStore Cluster using a supported version by KubeDB operator. Then we are going to apply SingleStoreAutoscaler to set up autoscaling.

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 with version 8.7.10. Then, in the next section we will set up autoscaling for this database using SingleStoreAutoscaler CRD. Below is the YAML of the SingleStore CR that we are going to create,

apiVersion: kubedb.com/v1alpha2
kind: Singlestore
metadata:
  name: sdb-sample
  namespace: demo
spec:
  version: 8.7.10
  topology:
    aggregator:
      replicas: 2
      podTemplate:
        spec:
          containers:
            - name: singlestore
              resources:
                limits:
                  memory: "2Gi"
                  cpu: "0.7"
                requests:
                  memory: "2Gi"
                  cpu: "0.7"
      storage:
        storageClassName: "standard"
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 1Gi
    leaf:
      replicas: 3
      podTemplate:
        spec:
          containers:
            - name: singlestore
              resources:
                limits:
                  memory: "2Gi"
                  cpu: "0.7"
                requests:
                  memory: "2Gi"
                  cpu: "0.7"
      storage:
        storageClassName: "standard"
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 10Gi
  licenseSecret:
    name: license-secret
  storageType: Durable
  deletionPolicy: WipeOut

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

$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.8-rc.0/docs/examples/singlestore/autoscaling/compute/sdb-cluster.yaml
singlestore.kubedb.com/sdb-cluster created

Now, wait until sdb-sample has status Ready. i.e,

NAME                                TYPE                  VERSION   STATUS   AGE
singlestore.kubedb.com/sdb-sample   kubedb.com/v1alpha2   8.7.10    Ready    4m35s

Let’s check the aggregator pod containers resources,

kubectl get pod -n demo sdb-sample-aggregator-0 -o json | jq '.spec.containers[].resources'
{
  "limits": {
    "cpu": "700m",
    "memory": "2Gi"
  },
  "requests": {
    "cpu": "700m",
    "memory": "2Gi"
  }
}

Let’s check the SingleStore aggregator node resources,

kubectl get singlestore -n demo sdb-sample -o json | jq '.spec.topology.aggregator.podTemplate.spec.containers[] | select(.name == "singlestore") | .resources'
{
  "limits": {
    "cpu": "700m",
    "memory": "2Gi"
  },
  "requests": {
    "cpu": "700m",
    "memory": "2Gi"
  }
}

You can see from the above outputs that the resources are same as the one we have assigned while deploying the singlestore.

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

Compute Resource Autoscaling

Here, we are going to set up compute resource autoscaling using a SingleStoreAutoscaler Object.

Create SingleStoreAutoscaler Object

In order to set up compute resource autoscaling for this singlestore cluster, we have to create a SingleStoreAutoscaler CRO with our desired configuration. Below is the YAML of the SingleStoreAutoscaler object that we are going to create,

apiVersion: autoscaling.kubedb.com/v1alpha1
kind: SinglestoreAutoscaler
metadata:
  name: sdb-cluster-autoscaler
  namespace: demo
spec:
  databaseRef:
    name: sdb-sample
  compute:
    aggregator:
      trigger: "On"
      podLifeTimeThreshold: 5m
      minAllowed:
        cpu: 900m
        memory: 3Gi
      maxAllowed:
        cpu: 2000m
        memory: 6Gi
      controlledResources: ["cpu", "memory"]
      containerControlledValues: "RequestsAndLimits"
      resourceDiffPercentage: 10

Here,

  • spec.databaseRef.name specifies that we are performing compute resource scaling operation on sdb-sample cluster.
  • spec.compute.aggregator.trigger or spec.compute.leaf.trigger specifies that compute autoscaling is enabled for this cluster.
  • spec.compute.aggregator.podLifeTimeThreshold or spec.compute.leaf.podLifeTimeThreshold specifies the minimum lifetime for at least one of the pod to initiate a vertical scaling.
  • spec.compute.aggregator.resourceDiffPercentage or spec.compute.leaf.resourceDiffPercentage specifies the minimum resource difference in percentage. The default is 10%.If the difference between current & recommended resource is less than ResourceDiffPercentage, Autoscaler Operator will ignore the updating.
  • spec.compute.aggregator.minAllowed or spec.compute.leaf.minAllowed specifies the minimum allowed resources for the cluster.
  • spec.compute.aggregator.maxAllowed or spec.compute.leaf.maxAllowed specifies the maximum allowed resources for the cluster.
  • spec.compute.aggregator.controlledResources or spec.compute.leaf.controlledResources specifies the resources that are controlled by the autoscaler.
  • spec.compute.aggregator.containerControlledValues or spec.compute.leaf.containerControlledValues specifies which resource values should be controlled. The default is “RequestsAndLimits”.
  • spec.opsRequestOptions contains the options to pass to the created OpsRequest. It has 2 fields.
    • timeout specifies the timeout for the OpsRequest.
    • apply specifies when the OpsRequest should be applied. The default is “IfReady”.

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

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.8-rc.0/docs/examples/singlestore/autoscaler/compute/sdb-cluster-autoscaler.yaml
singlestoreautoscaler.autoscaling.kubedb.com/sdb-cluster-autoscaler created

Verify Autoscaling is set up successfully

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

$ kubectl describe singlestoreautoscaler -n demo sdb-cluster-autoscaler 
Name:         sdb-cluster-autoscaler
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  autoscaling.kubedb.com/v1alpha1
Kind:         SinglestoreAutoscaler
Metadata:
  Creation Timestamp:  2024-09-10T08:55:26Z
  Generation:          1
  Owner References:
    API Version:           kubedb.com/v1alpha2
    Block Owner Deletion:  true
    Controller:            true
    Kind:                  Singlestore
    Name:                  sdb-sample
    UID:                   f81d0592-9dda-428a-b0b4-e72ab3643e22
  Resource Version:        424275
  UID:                     6b7b3d72-b92f-4e6f-88eb-4e891c24c550
Spec:
  Compute:
    Aggregator:
      Container Controlled Values:  RequestsAndLimits
      Controlled Resources:
        cpu
        memory
      Max Allowed:
        Cpu:     2
        Memory:  6Gi
      Min Allowed:
        Cpu:                     900m
        Memory:                  3Gi
      Pod Life Time Threshold:   5m0s
      Resource Diff Percentage:  10
      Trigger:                   On
  Database Ref:
    Name:  sdb-sample
  Ops Request Options:
    Apply:  IfReady
Status:
  Checkpoints:
    Cpu Histogram:
      Bucket Weights:
        Index:              0
        Weight:             2455
        Index:              1
        Weight:             2089
        Index:              2
        Weight:             10000
        Index:              3
        Weight:             361
      Reference Timestamp:  2024-09-10T09:05:00Z
      Total Weight:         5.5790751974302655
    First Sample Start:     2024-09-10T08:59:26Z
    Last Sample Start:      2024-09-10T09:15:18Z
    Last Update Time:       2024-09-10T09:15:27Z
    Memory Histogram:
      Bucket Weights:
        Index:              1
        Weight:             1821
        Index:              2
        Weight:             10000
      Reference Timestamp:  2024-09-10T09:05:00Z
      Total Weight:         14.365194626381038
    Ref:
      Container Name:     singlestore-coordinator
      Vpa Object Name:    sdb-sample-aggregator
    Total Samples Count:  32
    Version:              v3
    Cpu Histogram:
      Bucket Weights:
        Index:              5
        Weight:             3770
        Index:              6
        Weight:             10000
        Index:              7
        Weight:             132
        Index:              20
        Weight:             118
      Reference Timestamp:  2024-09-10T09:05:00Z
      Total Weight:         6.533759718059768
    First Sample Start:     2024-09-10T08:59:26Z
    Last Sample Start:      2024-09-10T09:16:19Z
    Last Update Time:       2024-09-10T09:16:28Z
    Memory Histogram:
      Bucket Weights:
        Index:              17
        Weight:             8376
        Index:              18
        Weight:             10000
      Reference Timestamp:  2024-09-10T09:05:00Z
      Total Weight:         17.827743425726553
    Ref:
      Container Name:     singlestore
      Vpa Object Name:    sdb-sample-aggregator
    Total Samples Count:  34
    Version:              v3
  Conditions:
    Last Transition Time:  2024-09-10T08:59:43Z
    Message:               Successfully created SinglestoreOpsRequest demo/sdbops-sdb-sample-aggregator-c0u141
    Observed Generation:   1
    Reason:                CreateOpsRequest
    Status:                True
    Type:                  CreateOpsRequest
  Vpas:
    Conditions:
      Last Transition Time:  2024-09-10T08:59:42Z
      Status:                True
      Type:                  RecommendationProvided
    Recommendation:
      Container Recommendations:
        Container Name:  singlestore
        Lower Bound:
          Cpu:     900m
          Memory:  3Gi
        Target:
          Cpu:     900m
          Memory:  3Gi
        Uncapped Target:
          Cpu:     100m
          Memory:  351198544
        Upper Bound:
          Cpu:     2
          Memory:  6Gi
    Vpa Name:      sdb-sample-aggregator
Events:            <none>

So, the singlestoreautoscaler resource is created successfully.

you can see in the Status.VPAs.Recommendation section, that recommendation has been generated for our database. Our autoscaler operator continuously watches the recommendation generated and creates an singlestoreopsrequest based on the recommendations, if the database pods resources are needed to scaled up or down.

Let’s watch the singlestoreopsrequest in the demo namespace to see if any singlestoreopsrequest object is created. After some time you’ll see that a singlestoreopsrequest will be created based on the recommendation.

$ watch kubectl get singlestoreopsrequest -n demo
Every 2.0s: kubectl get singlestoreopsrequest -n demo
NAME                                       TYPE              STATUS       AGE
sdbops-sdb-sample-aggregator-c0u141     VerticalScaling    Progressing    10s

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

$ kubectl get singlestoreopsrequest -n demo
NAME                                       TYPE              STATUS       AGE
sdbops-sdb-sample-aggregator-c0u141      VerticalScaling    Successful    3m2s

We can see from the above output that the SinglestoreOpsRequest has succeeded. If we describe the SinglestoreOpsRequest we will get an overview of the steps that were followed to scale the cluster.

$ kubectl describe singlestoreopsrequest -n demo sdbops-sdb-sample-aggregator-c0u141 
Name:         sdbops-sdb-sample-aggregator-c0u141
Namespace:    demo
Labels:       app.kubernetes.io/component=database
              app.kubernetes.io/instance=sdb-sample
              app.kubernetes.io/managed-by=kubedb.com
              app.kubernetes.io/name=singlestores.kubedb.com
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         SinglestoreOpsRequest
Metadata:
  Creation Timestamp:  2024-09-10T08:59:43Z
  Generation:          1
  Owner References:
    API Version:           autoscaling.kubedb.com/v1alpha1
    Block Owner Deletion:  true
    Controller:            true
    Kind:                  SinglestoreAutoscaler
    Name:                  sdb-cluster-autoscaler
    UID:                   6b7b3d72-b92f-4e6f-88eb-4e891c24c550
  Resource Version:        406111
  UID:                     978a1a00-f217-4326-b103-f66bbccf2943
Spec:
  Apply:  IfReady
  Database Ref:
    Name:  sdb-sample
  Type:    VerticalScaling
  Vertical Scaling:
    Aggregator:
      Resources:
        Limits:
          Cpu:     900m
          Memory:  3Gi
        Requests:
          Cpu:     900m
          Memory:  3Gi
Status:
  Conditions:
    Last Transition Time:  2024-09-10T09:01:55Z
    Message:               Timeout: request did not complete within requested timeout - context deadline exceeded
    Observed Generation:   1
    Reason:                Failed
    Status:                True
    Type:                  VerticalScaling
    Last Transition Time:  2024-09-10T08:59:46Z
    Message:               Successfully paused database
    Observed Generation:   1
    Reason:                DatabasePauseSucceeded
    Status:                True
    Type:                  DatabasePauseSucceeded
    Last Transition Time:  2024-09-10T08:59:46Z
    Message:               Successfully updated PetSets Resources
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2024-09-10T09:01:21Z
    Message:               Successfully Restarted Pods With Resources
    Observed Generation:   1
    Reason:                RestartPods
    Status:                True
    Type:                  RestartPods
    Last Transition Time:  2024-09-10T08:59:52Z
    Message:               get pod; ConditionStatus:True; PodName:sdb-sample-aggregator-0
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--sdb-sample-aggregator-0
    Last Transition Time:  2024-09-10T08:59:52Z
    Message:               evict pod; ConditionStatus:True; PodName:sdb-sample-aggregator-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--sdb-sample-aggregator-0
    Last Transition Time:  2024-09-10T09:00:31Z
    Message:               check pod ready; ConditionStatus:True; PodName:sdb-sample-aggregator-0
    Observed Generation:   1
    Status:                True
    Type:                  CheckPodReady--sdb-sample-aggregator-0
    Last Transition Time:  2024-09-10T09:00:36Z
    Message:               get pod; ConditionStatus:True; PodName:sdb-sample-aggregator-1
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--sdb-sample-aggregator-1
    Last Transition Time:  2024-09-10T09:00:36Z
    Message:               evict pod; ConditionStatus:True; PodName:sdb-sample-aggregator-1
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--sdb-sample-aggregator-1
    Last Transition Time:  2024-09-10T09:01:16Z
    Message:               check pod ready; ConditionStatus:True; PodName:sdb-sample-aggregator-1
    Observed Generation:   1
    Status:                True
    Type:                  CheckPodReady--sdb-sample-aggregator-1
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                                                   Age   From                         Message
  ----     ------                                                                   ----  ----                         -------
  Normal   Starting                                                                 25m   KubeDB Ops-manager Operator  Start processing for SinglestoreOpsRequest: demo/sdbops-sdb-sample-aggregator-c0u141
  Normal   Starting                                                                 25m   KubeDB Ops-manager Operator  Pausing Singlestore database: demo/sdb-sample
  Normal   Successful                                                               25m   KubeDB Ops-manager Operator  Successfully paused Singlestore database: demo/sdb-sample for SinglestoreOpsRequest: sdbops-sdb-sample-aggregator-c0u141
  Normal   UpdatePetSets                                                            25m   KubeDB Ops-manager Operator  Successfully updated PetSets Resources
  Warning  get pod; ConditionStatus:True; PodName:sdb-sample-aggregator-0           25m   KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:sdb-sample-aggregator-0
  Warning  evict pod; ConditionStatus:True; PodName:sdb-sample-aggregator-0         25m   KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:sdb-sample-aggregator-0
  Warning  check pod ready; ConditionStatus:False; PodName:sdb-sample-aggregator-0  25m   KubeDB Ops-manager Operator  check pod ready; ConditionStatus:False; PodName:sdb-sample-aggregator-0
  Warning  check pod ready; ConditionStatus:True; PodName:sdb-sample-aggregator-0   24m   KubeDB Ops-manager Operator  check pod ready; ConditionStatus:True; PodName:sdb-sample-aggregator-0
  Warning  get pod; ConditionStatus:True; PodName:sdb-sample-aggregator-1           24m   KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:sdb-sample-aggregator-1
  Warning  evict pod; ConditionStatus:True; PodName:sdb-sample-aggregator-1         24m   KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:sdb-sample-aggregator-1
  Warning  check pod ready; ConditionStatus:False; PodName:sdb-sample-aggregator-1  24m   KubeDB Ops-manager Operator  check pod ready; ConditionStatus:False; PodName:sdb-sample-aggregator-1
  Warning  check pod ready; ConditionStatus:True; PodName:sdb-sample-aggregator-1   24m   KubeDB Ops-manager Operator  check pod ready; ConditionStatus:True; PodName:sdb-sample-aggregator-1
  Normal   RestartPods                                                              24m   KubeDB Ops-manager Operator  Successfully Restarted Pods With Resources
  Normal Starting
  Normal Successful

Now, we are going to verify from the Pod, and the singlestore yaml whether the resources of the topology database has updated to meet up the desired state, Let’s check,

kubectl get pod -n demo sdb-sample-aggregator-0 -o json | jq '.spec.containers[].resources'
{
  "limits": {
    "cpu": "900m",
    "memory": "3Gi"
  },
  "requests": {
    "cpu": "900m",
    "memory": "3Gi"
  }
}


kubectl get singlestore -n demo sdb-sample -o json | jq '.spec.topology.aggregator.podTemplate.spec.containers[] | select(.name == "singlestore") | .resources'
{
  "limits": {
    "cpu": "900m",
    "memory": "3Gi"
  },
  "requests": {
    "cpu": "900m",
    "memory": "3Gi"
  }
}

The above output verifies that we have successfully auto scaled the resources of the SingleStore cluster.

Cleaning Up

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

kubectl delete singlestoreopsrequest -n demo sdbops-sdb-sample-aggregator-c0u141
kubectl delete singlestoreautoscaler -n demo sdb-cluster-autoscaler
kubectl delete kf -n demo sdb-sample
kubectl delete ns demo

Next Steps