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MySQL Volume Expansion

This guide will give an overview on how KubeDB Enterprise operator expand the volume of MySQL.

Before You Begin

• You should be familiar with the following KubeDB concepts:
  • MySQL
  • MySQLOpsRequest

How Volume Expansion Process Works

The following diagram shows how KubeDB Enterprise operator expand the volumes of MySQL database components. Open the image in a new tab to see the enlarged version.

  

The Volume Expansion process consists of the following steps:

1. At first, a user creates a MySQL Custom Resource (CR).

2. KubeDB Community operator watches the MySQL CR.

3. When the operator finds a MySQL CR, it creates required StatefulSet and related necessary stuff like secrets, services, etc.

4. The statefulSet creates Persistent Volumes according to the Volume Claim Template provided in the statefulset configuration. This Persistent Volume will be expanded by the KubeDB Enterprise operator.

5. Then, in order to expand the volume of the MySQL database the user creates a MySQLOpsRequest CR with desired information.

6. KubeDB Enterprise operator watches the MySQLOpsRequest CR.

7. When it finds a MySQLOpsRequest CR, it pauses the MySQL object which is referred from the MySQLOpsRequest. So, the KubeDB Community operator doesn’t perform any operations on the MySQL object during the volume expansion process.

8. Then the KubeDB Enterprise operator will expand the persistent volume to reach the expected size defined in the MySQLOpsRequest CR.

9. After the successfully expansion of the volume of the related StatefulSet Pods, the KubeDB Enterprise operator updates the new volume size in the MySQL object to reflect the updated state.

10. After the successful Volume Expansion of the MySQL, the KubeDB Enterprise operator resumes the MySQL object so that the KubeDB Community operator resumes its usual operations.

In the next docs, we are going to show a step by step guide on Volume Expansion of various MySQL database using MySQLOpsRequest CRD.