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.

   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
   

   kubectl edit cluster mycluster -n demo
   

   Configure the value of spec.componentSpecs.replicas as 0 to delete pods.

   ...
   spec:
     clusterDefinitionRef: kafka
     clusterVersionRef: kafka-3.3.2
     terminationPolicy: Delete
     componentSpecs:
     - name: kafka
       componentDefRef: kafka
       disableExporter: true  
       replicas: 0 # Change this value
   ...
   

   kbcli cluster stop mycluster -n demo
   

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

   kubectl get cluster mycluster -n demo
   

   kbcli cluster list -n demo
   

Start a cluster

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

   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 
   

   kubectl edit cluster mycluster -n demo
   

   Change the value of spec.componentSpecs.replicas back to the original amount to start this cluster again.

   ...
   spec:
     clusterDefinitionRef: kafka
     clusterVersionRef: kafka-3.3.2
     terminationPolicy: Delete
     componentSpecs:
     - name: kafka
       componentDefRef: kafka
       disableExporter: true   
       replicas: 1 # Change this value
   ...
   

   kbcli cluster start mycluster -n demo
   

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

   kubectl get cluster mycluster -n demo
   

   kbcli cluster list -n demo