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ClickHouse Vertical Scaling
This guide will give an overview on how KubeDB Ops-manager operator updates the resources(for example CPU and Memory etc.) of the ClickHouse
.
Before You Begin
- You should be familiar with the following
KubeDB
concepts:
How Vertical Scaling Process Works
The following diagram shows how KubeDB Ops-manager operator updates the resources of the ClickHouse
. Open the image in a new tab to see the enlarged version.
The vertical scaling process consists of the following steps:
At first, a user creates a
ClickHouse
Custom Resource (CR).KubeDB
Provisioner operator watches theClickHouse
CR.When the operator finds a
ClickHouse
CR, it creates required number ofPetSets
and related necessary stuff like secrets, services, etc.Then, in order to update the resources(for example
CPU
,Memory
etc.) of theClickHouse
cluster, the user creates aClickHouseOpsRequest
CR with desired information.KubeDB
Ops-manager operator watches theClickHouseOpsRequest
CR.When it finds a
ClickHouseOpsRequest
CR, it halts theClickHouse
object which is referred from theClickHouseOpsRequest
. So, theKubeDB
Provisioner operator doesn’t perform any operations on theClickHouse
object during the vertical scaling process.Then the
KubeDB
Ops-manager operator will update resources of the PetSet Pods to reach desired state.After the successful update of the resources of the PetSet’s replica, the
KubeDB
Ops-manager operator updates theClickHouse
object to reflect the updated state.After the successful update of the
ClickHouse
resources, theKubeDB
Ops-manager operator resumes theClickHouse
object so that theKubeDB
Provisioner operator resumes its usual operations.
In the next docs, we are going to show a step by step guide on updating resources of ClickHouse database using ClickHouseOpsRequest
CRD.