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PostgreSQL Volume Expansion
This guide will give an overview on how KubeDB Ops-manager operator expand the volume of Postgres
components such as Standalone, HA cluster etc.
Before You Begin
- You should be familiar with the following
KubeDB
concepts:
Volume Expansion Working Procedure
The following diagram shows how KubeDB Ops-manager operator expand the volumes of Postgres
database components. Open the image in a new tab to see the enlarged version.
The Volume Expansion process consists of the following steps:
At first, a user creates a
Postgres
Custom Resource (CR).KubeDB
community operator watches thePostgres
CR.When the operator finds a
Postgres
CR, it creates aPetSet
and related necessary stuffs like pods, pvc, secret, service etc.Each PetSet creates a Persistent Volume according to the Volume Claim Template provided in the Petset configuration. This Persistent Volume will be expanded by the
KubeDB
Ops-manager operator.Then, in order to expand the volume of the various components (Standalone, HA cluster etc.) of the
Postgres
database, the user creates aPostgresOpsRequest
CR with desired information.KubeDB
Ops-manager operator watches thePostgresOpsRequest
CR.When it finds a
PostgresOpsRequest
CR, it halts thePostgres
object which is referred from thePostgresOpsRequest
. So, theKubeDB
Provisioner operator doesn’t perform any operations on thePostgres
object during the volume expansion process.Then the
KubeDB
Ops-manager operator will expand the persistent volume to reach the expected size defined in thePostgresOpsRequest
CR.After the successful expansion of the volume of the related PetSet Pods the
KubeDB
Ops-manager operator updates the new volume size in thePostgres
object to reflect the updated state.After the successful Volume Expansion of the
Postgres
components, theKubeDB
Ops-manager operator resumes thePostgres
object so that theKubeDB
Provisioner operator resumes its usual operations.
In the next docs, we are going to show you a step-by-step guide on Volume Expansion of various Postgres database components using PostgresOpsRequest
CRD.