deploy_radondb-mysql_operator_on_k8s.md

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Contents

• Install a RadonDB MySQL cluster on Kubernetes
  • Overview
  • Prerequisites
  • Procedure
    • Step 1: Add a Helm repository
    • Step 2: Install Operator
    • Step 3: Deploy a RadonDB MySQL cluster
  • Verification
    • Verify RadonDB MySQL Operator
    • Verify the RadonDB MySQL cluster
  • Access RadonDB MySQL
  • Uninstallation
    • Uninstall Operator
    • Uninstall RadonDB MySQL
    • Uninstall the custom resources

Install a RadonDB MySQL cluster on Kubernetes

Overview

RadonDB MySQL is an open-source, high-availability, and cloud-native database cluster solution based on MySQL. It supports the high-availability architecture of one leader node and multiple replicas, with a set of management functions for security, automatic backup, monitoring and alarming, automatic scaling, and so on. RadonDB MySQL has been widely used in production by banks, insurance enterprises, and other traditional large enterprises.

RadonDB MySQL can be deployed and managed on Kubernetes to automate tasks relevant to RadonDB MySQL clusters.

This tutorial demonstrates how to deploy a RadonDB MySQL cluster (Operator) on Kubernetes.

Prerequisites

• You need to prepare a Kubernetes cluster.

Procedure

Step 1: Add a Helm repository.

helm repo add radondb https://radondb.github.io/radondb-mysql-kubernetes/

Check that a chart named radondb/mysql-operator exists in the repository.

$ helm search repo
NAME                            CHART VERSION   APP VERSION                     DESCRIPTION                 
radondb/mysql-operator          0.1.0           v2.1.0                          Open Source，High Availability Cluster，based on MySQL                     

Step 2: Install Operator

The following sets the release name to demo and creates a Deployment named demo-mysql-operator.

helm install demo radondb/mysql-operator

Note

This step also creates the CRD required by the cluster.

Step 3: Deploy a RadonDB MySQL cluster

Create an instance of the mysqlclusters.mysql.radondb.com CRD and thereby create a RadonDB MySQL cluster with default parameters as follows. To set cluster parameters, see Configuration Parameters.

kubectl apply -f https://github.com/radondb/radondb-mysql-kubernetes/releases/latest/download/mysql_v1alpha1_mysqlcluster.yaml

Verification

Verify RadonDB MySQL Operator

Check the demo Deployment and its monitoring service. The deployment is successful if the following information is displayed.

$ kubectl get deployment,svc
NAME                  READY   UP-TO-DATE   AVAILABLE   AGE
demo-mysql-operator   1/1     1            1           7h50m


NAME                             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
service/mysql-operator-metrics   ClusterIP   10.96.142.22    <none>        8443/TCP   8h

Verify the RadonDB MySQL cluster

Run the following command to check the CRDs:

$ kubectl get crd | grep mysql.radondb.com
backups.mysql.radondb.com                             2021-11-02T07:00:01Z
mysqlclusters.mysql.radondb.com                       2021-11-02T07:00:01Z
mysqlusers.mysql.radondb.com                          2021-11-02T07:00:01Z

Run the following command to check the cluster. If a statefulset of three replicas (RadonDB MySQL nodes) and services used to access the nodes are displayed, the installation is successful.

$ kubectl get statefulset,svc
NAME           READY   AGE
sample-mysql   3/3     7h33m

NAME                             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
service/sample-follower          ClusterIP   10.96.131.84    <none>        3306/TCP   7h37m
service/sample-leader            ClusterIP   10.96.111.214   <none>        3306/TCP   7h37m
service/sample-mysql             ClusterIP   None            <none>        3306/TCP   7h37m

Access RadonDB MySQL

Note

You need to prepare a client used to connect to MySQL.

• If the client is installed in a different Kubernetes cluster, see Access Applications in a Cluster to configure port forwarding and load balancing.

• You can use service_name or clusterIP to access RadonDB MySQL in the Kubernetes cluster.

  Note

  RadonDB MySQL provides a leader service and a follower service, which are used to access the leader node and follower nodes respectively. The leader service always points to the leader node that supports read and write, and the follower service always points to the follower nodes that are read-only.

The following demonstrates how to access RadonDB MySQL by using a client in the same Kubernetes cluster as the database.

Use ClusterIP

The HA read/write IP address of RadonDB MySQL points to the clusterIP of the leader service, and the HA read-only IP address points to the clusterIP of the follower services.

mysql -h <clusterIP> -P <mysql_Port> -u <user_name> -p

For example, run the following command to access a leader service. The username is radondb_usr, and the clusterIP of the leader service is 10.10.128.136.

mysql -h 10.10.128.136 -P 3306 -u radondb_usr -p

Use service_name

Pods in the Kubernetes cluster can access RadonDB MySQL by using service_name.

Note

service_name cannot be used to access database pods from the host machines in the Kubernetes cluster.

• Access the leader service (RadonDB MySQL leader node)

  mysql -h <leader_service_name>.<namespace> -u <user_name> -p

  For example, run the following command to access the leader service. The username is radondb_usr, the release name is sample, and the namespace of RadonDB MySQL is default.

  mysql -h sample-leader.default -u radondb_usr -p

• Access the follower service (RadonDB MySQL replicas)

  mysql -h <follower_service_name>.<namespace> -u <user_name> -p

  For example, run the following command to access the follower service. The username is radondb_usr, the release name is sample, and the namespace of RadonDB MySQL is default.

  mysql -h sample-follower.default -u radondb_usr -p  

Uninstallation

Uninstall Operator

Uninstall RadonDB MySQL Operator with the release name demo in the current namespace.

helm delete demo

Uninstall RadonDB MySQL

Uninstall the RadonDB MySQL cluster with the release name sample.

kubectl delete mysqlclusters.mysql.radondb.com sample

Uninstall the custom resources

kubectl delete customresourcedefinitions.apiextensions.k8s.io mysqlclusters.mysql.radondb.com
kubectl delete customresourcedefinitions.apiextensions.k8s.io mysqlusers.mysql.radondb.com
kubectl delete customresourcedefinitions.apiextensions.k8s.io backups.mysql.radondb.com