Stop/Start a Kafka Cluster

You can stop/start a cluster to save computing resources. When a cluster is stopped, the computing resources of this cluster are released, which means the pods of Kubernetes are released, but the storage resources are reserved. Start this cluster again if you want to restore the cluster resources from the original storage by snapshots.

Stop a cluster

Steps:

1. Configure the name of your cluster and run the command below to stop this cluster.

   kbcli

   kbcli cluster stop mycluster -n demo

   OpsRequest

   Run the command below to stop a cluster.

   kubectl apply -f - <<EOF
   apiVersion: apps.kubeblocks.io/v1alpha1
   kind: OpsRequest
   metadata:
     name: ops-stop
     namespace: demo
   spec:
     clusterName: mycluster
     type: Stop
   EOF

   Edit cluster YAML file

   Configure replicas as 0 to delete pods.

   kubectl edit cluster mycluster -n demo
   >
   apiVersion: apps.kubeblocks.io/v1alpha1
   kind: Cluster
   metadata:
     name: mycluster
     namespace: demo
   spec:
     clusterDefinitionRef: kafka
     clusterVersionRef: kafka-3.3.2
     terminationPolicy: Delete
     componentSpecs:
     - name: kafka
       componentDefRef: kafka
       disableExporter: true  
       replicas: 0
       volumeClaimTemplates:
       - name: data
         spec:
           storageClassName: standard
           accessModes:
             - ReadWriteOnce
           resources:
             requests:
               storage: 20Gi

2. Check the status of the cluster to see whether it is stopped.

   kbcli

   kbcli cluster list -n demo

   kubectl

   kubectl get cluster mycluster -n demo

Start a cluster

1. Configure the name of your cluster and run the command below to start this cluster.

   kbcli

   kbcli cluster start mycluster -n demo

   OpsRequest

   Apply an OpsRequest to start the cluster.

   kubectl apply -f - <<EOF
   apiVersion: apps.kubeblocks.io/v1alpha1
   kind: OpsRequest
   metadata:
     name: ops-start
     namespace: demo
   spec:
     clusterName: mycluster
     type: Start
   EOF 

   Edit cluster YAML File

   Change replicas back to the original amount to start this cluster again.

   apiVersion: apps.kubeblocks.io/v1alpha1
   kind: Cluster
   metadata:
     name: mycluster
     namespace: demo
   spec:
     clusterDefinitionRef: kafka
     clusterVersionRef: kafka-3.3.2
     terminationPolicy: Delete
     componentSpecs:
     - name: kafka
       componentDefRef: kafka
       disableExporter: true   
       replicas: 1
       volumeClaimTemplates:
       - name: data
         spec:
           storageClassName: standard
           accessModes:
             - ReadWriteOnce
           resources:
             requests:
               storage: 20Gi

2. Check the status of the cluster to see whether it is running again.

   kbcli

   kbcli cluster list -n demo

   kubectl

   kubectl get cluster mycluster -n demo