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Version: release-0.9

Create and connect to an ApeCloud MySQL cluster

This tutorial shows how to create and connect to an ApeCloud MySQL cluster.

Create a MySQL cluster​

Before you start​

  • Install kbcli if you want to create and connect a MySQL cluster by kbcli.

  • Install KubeBlocks.

  • Check whether the ApeCloud MySQL Addon is enabled. The ApeCloud MySQL Addon is enabled by KubeBlocks by default. If you disable it when installing KubeBlocks,enable it first.

    kubectl get addons.extensions.kubeblocks.io apecloud-mysql
    >
    NAME             TYPE   VERSION   PROVIDER   STATUS    AGE
    apecloud-mysql   Helm                        Enabled   61m

  • View all the database types and versions available for creating a cluster.

    Make sure the apecloud-mysql cluster definition is installed.

    kubectl get clusterdefinition apecloud-mysql
    >
    NAME             TOPOLOGIES   SERVICEREFS   STATUS      AGE
    apecloud-mysql                              Available   85m

    View all available versions for creating a cluster.

    kubectl get clusterversions -l clusterdefinition.kubeblocks.io/name=apecloud-mysql
    >
    NAME                CLUSTER-DEFINITION   STATUS      AGE
    ac-mysql-8.0.30     apecloud-mysql       Available   85m

  • To keep things isolated, create a separate namespace called demo throughout this tutorial.

    kubectl create namespace demo

Create a cluster​

KubeBlocks supports creating two types of ApeCloud MySQL clusters: Standalone and RaftGroup Cluster. Standalone only supports one replica and can be used in scenarios with lower requirements for availability. For scenarios with high availability requirements, it is recommended to create a RaftGroup Cluster, which creates a cluster with three replicas. To ensure high availability, all replicas are distributed on different nodes by default.

  1. Create an ApeCloud MySQL cluster.

    KubeBlocks implements a Cluster CRD to define a cluster. Here is an example of creating a RaftGroup Cluster.

    If you only have one node for deploying a RaftGroup Cluster, set spec.affinity.topologyKeys as null. But for a production environment, it is not recommended to deploy all replicas on one node, which may decrease the cluster availability.

    cat <<EOF | kubectl apply -f -
    apiVersion: apps.kubeblocks.io/v1alpha1
    kind: Cluster
    metadata:
      name: mycluster
      namespace: demo
    spec:
      terminationPolicy: Delete
      componentSpecs:
      - name: mysql
        componentDef: apecloud-mysql
        affinity:
          podAntiAffinity: Preferred
          topologyKeys:
          - kubernetes.io/hostname
          tenancy: SharedNode
        tolerations:
        - key: kb-data
          operator: Equal
          value: 'true'
          effect: NoSchedule
        enabledLogs:
        - error
        - general
        - slow
        disableExporter: true
        replicas: 2
        resources:
          limits:
            cpu: '0.5'
            memory: 0.5Gi
          requests:
            cpu: '0.5'
            memory: 0.5Gi
        volumeClaimTemplates:
        - name: data
          spec:
            accessModes:
            - ReadWriteOnce
            resources:
              requests:
                storage: 20Gi
    EOF
    FieldDefinition
    spec.terminationPolicyIt is the policy of cluster termination. The default value is Delete. Valid values are DoNotTerminate, Delete, WipeOut. For the detailed definition, you can refer to Termination Policy.
    spec.affinityIt defines a set of node affinity scheduling rules for the cluster's Pods. This field helps control the placement of Pods on nodes within the cluster.
    spec.affinity.podAntiAffinityIt specifies the anti-affinity level of Pods within a component. It determines how pods should spread across nodes to improve availability and performance.
    spec.affinity.topologyKeysIt represents the key of node labels used to define the topology domain for Pod anti-affinity and Pod spread constraints.
    spec.tolerationsIt is an array that specifies tolerations attached to the cluster's Pods, allowing them to be scheduled onto nodes with matching taints.
    spec.componentSpecsIt is the list of components that define the cluster components. This field allows customized configuration of each component within a cluster.
    spec.componentSpecs.componentDefRefIt is the name of the component definition that is defined in the cluster definition and you can get the component definition names with kubectl get clusterdefinition apecloud-mysql -o json | jq '.spec.componentDefs[].name'.
    spec.componentSpecs.nameIt specifies the name of the component.
    spec.componentSpecs.disableExporterIt defines whether the monitoring function is enabled.
    spec.componentSpecs.replicasIt specifies the number of replicas of the component.
    spec.componentSpecs.resourcesIt specifies the resource requirements of the component.

    KubeBlocks operator watches for the Cluster CRD and creates the cluster and all dependent resources. You can get all the resources created by the cluster by running the command below.

    kubectl get all,secret,rolebinding,serviceaccount -l app.kubernetes.io/instance=mycluster -n demo

    Run the following command to view the details of the created ApeCloud MySQL cluster:

    kubectl get cluster mycluster -n demo -o yaml

  2. Verify whether this cluster is created successfully.

    kubectl get cluster mycluster -n demo
    >
    NAME        CLUSTER-DEFINITION   VERSION           TERMINATION-POLICY   STATUS    AGE
    mycluster   apecloud-mysql       ac-mysql-8.0.30   Delete               Running   12m

Connect to an ApeCloud MySQL Cluster​

You can use kubectl exec to exec into a Pod and connect to a database.

KubeBlocks operator creates a new Secret called mycluster-conn-credential to store the connection credential of the ApeCloud MySQL cluster. This secret contains the following keys:

  • username: the root username of the MySQL cluster.
  • password: the password of the root user.
  • port: the port of the MySQL cluster.
  • host: the host of the MySQL cluster.
  • endpoint: the endpoint of the MySQL cluster and it is the same as host:port.

  1. Run the command below to get the username and password for the kubectl exec command.

    kubectl get secrets -n demo mycluster-conn-credential -o jsonpath='{.data.username}' | base64 -d
    >
    root

    kubectl get secrets -n demo mycluster-conn-credential -o jsonpath='{.data.password}' | base64 -d
    >
    2gvztbvz

  2. Exec into the Pod mycluster-mysql-0 and connect to the database using username and password.

    kubectl exec -ti -n demo mycluster-mysql-0 -- bash

    mysql -uroot -p2gvztbvz

For the detailed database connection guide, refer to Connect database.