Deploy Nebula Graph clusters with Kubectl¶

Prerequisites¶

Install Nebula Operator

Create clusters¶

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

1. 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: v2.5.1
       service:
         type: NodePort
         externalTrafficPolicy: Local
       storageClaim:
         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: v2.5.1
       storageClaim:
         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: v2.5.1
       storageClaim:
         resources:
           requests:
             storage: 2Gi
         storageClassName: gp2
     reference:
       name: statefulsets.apps
       version: v1
     schedulerName: default-scheduler
     imagePullPolicy: IfNotPresent
   

   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	v2.5.1	The version of the Graphd service.
   spec.graphd.service	-	The Service configurations for the Graphd service.
   spec.graphd.storageClaim	-	The 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	v2.5.1	The version of the Metad service.
   spec.metad.storageClaim	-	The 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	v2.5.1	The version of the Storaged service.
   spec.storaged.storageClaim	-	The 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.

2. Create a Nebula Graph cluster.

   kubectl create -f apps_v1alpha1_nebulacluster.yaml
   

   Output:

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

3. 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-cluster   1                1              1               1             3                  3                31h
   

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:

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

     storaged:
       resources:
         requests:
           cpu: "1"
           memory: "1Gi"
         limits:
           cpu: "1"
           memory: "1Gi"
       replicas: 5
       image: vesoft/nebula-storaged
       version: v2.5.1
       storageClaim:
         resources:
           requests:
             storage: 2Gi
         storageClassName: fast-disks
   

2. Run the following command to update the Nebula Graph cluster CR.

   kubectl apply -f apps_v1alpha1_nebulacluster.yaml
   

3. 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.

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