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Hazelcast Vertical Autoscaling

This guide will give an overview on how KubeDB Autoscaler operator autoscales the database storage using hazelcastautoscaler crd.

Before You Begin

• You should be familiar with the following KubeDB concepts:
  • Hazelcast
  • HazelcastAutoscaler
  • HazelcastOpsRequest

How Storage Autoscaling Works

The following diagram shows how KubeDB Autoscaler operator autoscales the resources of Hazelcast cluster components. Open the image in a new tab to see the enlarged version.

  

The Auto Scaling process consists of the following steps:

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

2. KubeDB Provisioner operator watches the Hazelcast CR.

3. When the operator finds a Hazelcast CR, it creates required number of Statefulsets and related necessary stuff like secrets, services, etc.

• Each Statefulset creates a Persistent Volume according to the Volume Claim Template provided in the Statefulset configuration.

4. Then, in order to set up storage autoscaling of the various components (ie. Combined, Node) of the Hazelcast cluster, the user creates a HazelcastAutoscaler CRO with desired configuration.

5. KubeDB Autoscaler operator watches the HazelcastAutoscaler CRO.

6. KubeDB Autoscaler operator continuously watches persistent volumes of the clusters to check if it exceeds the specified usage threshold.

• If the usage exceeds the specified usage threshold, then KubeDB Autoscaler operator creates a HazelcastOpsRequest to expand the storage of the database.

7. KubeDB Ops-manager operator watches the HazelcastOpsRequest CRO.

8. Then the KubeDB Ops-manager operator will expand the storage of the cluster component as specified on the HazelcastOpsRequest CRO.

In the next docs, we are going to show a step by step guide on Autoscaling storage of various Hazelcast cluster components using HazelcastAutoscaler CRD.