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Redis Volume Expansion

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

Before You Begin

• You should be familiar with the following KubeDB concepts:
  • Redis
  • RedisOpsRequest

How Volume Expansion Process Works

The following diagram shows how KubeDB Enterprise operator expand the volumes of Redis 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 Redis Custom Resource (CR).

2. KubeDB Community operator watches the Redis CR.

3. When the operator finds a Redis 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 Redis database the user creates a RedisOpsRequest CR with desired information.

6. KubeDB Enterprise operator watches the RedisOpsRequest CR.

7. When it finds a RedisOpsRequest CR, it pauses the Redis object which is referred from the RedisOpsRequest. So, the KubeDB Community operator doesn’t perform any operations on the Redis 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 RedisOpsRequest CR.

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

10. After the successful Volume Expansion of the Redis, the KubeDB Enterprise operator resumes the Redis 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 Redis database using RedisOpsRequest CRD.