Deploy Nebula Graph clusters with Kubectl¶

Prerequisites¶

Create clusters¶

The following example shows how to create a Nebula Graph cluster by creating a cluster named nebula.

Create a file named apps_v1alpha1_nebulacluster.yaml.

The file contents are as follows:

apiVersion: apps.nebula-graph.io/v1alpha1
kind: NebulaCluster
metadata:
  name: nebula
spec:
  graphd:
    resources:
      requests:
        cpu: "500m"
        memory: "500Mi"
      limits:
        cpu: "1"
        memory: "1Gi"
    replicas: 1
    image: vesoft/nebula-graphd
    version: v2.6.0
    service:
      type: NodePort
      externalTrafficPolicy: Local
    logVolumeClaim:
      resources:
        requests:
          storage: 2Gi
      storageClassName: gp2
  metad:
    resources:
      requests:
        cpu: "500m"
        memory: "500Mi"
      limits:
        cpu: "1"
        memory: "1Gi"
    replicas: 1
    image: vesoft/nebula-metad
    version: v2.6.0
    dataVolumeClaim:
      resources:
        requests:
          storage: 2Gi
      storageClassName: gp2
    logVolumeClaim:
      resources:
        requests:
          storage: 2Gi
      storageClassName: gp2
  storaged:
    resources:
      requests:
        cpu: "500m"
        memory: "500Mi"
      limits:
        cpu: "1"
        memory: "1Gi"
    replicas: 3
    image: vesoft/nebula-storaged
    version: v2.6.0
    dataVolumeClaim:
      resources:
        requests:
          storage: 2Gi
      storageClassName: gp2
    logVolumeClaim:
      resources:
        requests:
          storage: 2Gi
      storageClassName: gp2
  reference:
    name: statefulsets.apps
    version: v1
  schedulerName: default-scheduler
  imagePullPolicy: Always

The parameters in the file are described as follows:

Parameter	Default value	Description
`metadata.name`	-	The name of the created Nebula Graph cluster.
`spec.graphd.replicas`	`1`	The numeric value of replicas of the Graphd service.
`spec.graphd.images`	`vesoft/nebula-graphd`	The container image of the Graphd service.
`spec.graphd.version`	`v2.6.0`	The version of the Graphd service.
`spec.graphd.service`	-	The Service configurations for the Graphd service.
`spec.graphd.logVolumeClaim.storageClassName`	-	The log disk storage configurations for the Graphd service.
`spec.metad.replicas`	`1`	The numeric value of replicas of the Metad service.
`spec.metad.images`	`vesoft/nebula-metad`	The container image of the Metad service.
`spec.metad.version`	`v2.6.0`	The version of the Metad service.
`spec.metad.dataVolumeClaim.storageClassName`	-	The data disk storage configurations for the Metad service.
`spec.metad.logVolumeClaim.storageClassName`	-	The log disk storage configurations for the Metad service.
`spec.storaged.replicas`	`3`	The numeric value of replicas of the Storaged service.
`spec.storaged.images`	`vesoft/nebula-storaged`	The container image of the Storaged service.
`spec.storaged.version`	`v2.6.0`	The version of the Storaged service.
`spec.storaged.dataVolumeClaim.storageClassName`	-	The data disk storage configurations for the Storaged service.
`spec.storaged.logVolumeClaim.storageClassName`	-	The log disk storage configurations for the Storaged service.
`spec.reference.name`	-	The name of the dependent controller.
`spec.schedulerName`	-	The scheduler name.
`spec.imagePullPolicy`	The image policy to pull the Nebula Graph image. For details, see Image pull policy.	The image pull policy in Kubernetes.

Create a Nebula Graph cluster.

kubectl create -f apps_v1alpha1_nebulacluster.yaml

Output:

nebulacluster.apps.nebula-graph.io/nebula created

Check the status of the Nebula Graph cluster.

kubectl get nebulaclusters.apps.nebula-graph.io nebula

Output:

NAME     GRAPHD-DESIRED   GRAPHD-READY   METAD-DESIRED   METAD-READY   STORAGED-DESIRED   STORAGED-READY   AGE
nebula   1                1              1               1             3                  3                86s

Scaling clusters¶

You can modify the value of replicas in apps_v1alpha1_nebulacluster.yaml to scale a Nebula Graph cluster.

Scale out clusters¶

The following shows how to scale out a Nebula Graph cluster by changing the number of Storage services to 5:

Change the value of the storaged.replicas from 3 to 5 in apps_v1alpha1_nebulacluster.yaml.

  storaged:
    resources:
      requests:
        cpu: "500m"
        memory: "500Mi"
      limits:
        cpu: "1"
        memory: "1Gi"
    replicas: 5
    image: vesoft/nebula-storaged
    version: v2.6.0
    dataVolumeClaim:
      resources:
        requests:
          storage: 2Gi
      storageClassName: gp2
    logVolumeClaim:
      resources:
        requests:
          storage: 2Gi
      storageClassName: gp2
  reference:
    name: statefulsets.apps
    version: v1
  schedulerName: default-scheduler

Run the following command to update the Nebula Graph cluster CR.
```
kubectl apply -f apps_v1alpha1_nebulacluster.yaml
```

Check the number of Storage services.

kubectl  get pods -l app.kubernetes.io/cluster=nebula

Output:

NAME                READY   STATUS    RESTARTS   AGE
nebula-graphd-0     1/1     Running   0          2m
nebula-metad-0      1/1     Running   0          2m
nebula-storaged-0   1/1     Running   0          2m
nebula-storaged-1   1/1     Running   0          2m
nebula-storaged-2   1/1     Running   0          2m
nebula-storaged-3   1/1     Running   0          5m
nebula-storaged-4   1/1     Running   0          5m

As you can see above, the number of Storage services is scaled up to 5.

Scale in clusters¶

The principle of scaling in a cluster is the same as scaling out a cluster. You scale in a cluster if the numeric value of the replicas in apps_v1alpha1_nebulacluster.yaml is changed smaller than the current number. For more information, see the Scale out clusters section above.

Caution

Nebula Operator currently only supports scaling Graph and Storage services and does not support scale Meta services.

Delete clusters¶

Run the following command to delete a Nebula Graph cluster with Kubectl:

kubectl delete -f apps_v1alpha1_nebulacluster.yaml

What's next¶

Connect to Nebula Graph databases

Last update: November 16, 2021