KubeBlocks
BlogsKubeBlocks Cloud

Getting Started

Introduction
Supported addons
Installation

Concepts and Features

Concepts

Backup and Restore

Introduction

Backup

Configure BackupRepo
Configure BackupPolicy
Scheduled backup
On-demand backup

Restore

Restore from backup set
Point-in-Time Recovery

In Place Update

Introduction
Enable in-place update

Instance Template

Introduction
Apply instance template

Trouble Shooting

FAQs

References

API Reference

Cluster
Operations
Parameters
Dataprotection
Add-On
Terminology
Install Addons
Install kbcli
Create a test Kubernetes cluster
Kubernetes and Operator 101

Upgrade KubeBlocks

Upgrade to v0.8
Upgrade to v0.9.0
Upgrade to v0.9.x

Release Notes

v1.0.0-cn
v1.0.0
v0.9.3
v0.9.2
v0.9.1
v0.9.0
  1. What is an instance template
  2. Why do we introduce the instance template

Introduction

What is an instance template

An instance serves as the fundamental unit in KubeBlocks, comprising a Pod along with several auxiliary objects. To simplify, you can initially think of it as a Pod, and henceforth, we'll consistently refer to it as an "Instance."

Starting from version 0.9, we're able to establish multiple instance templates for a particular component within a cluster. These instance templates include several fields such as Name, Replicas, Annotations, Labels, Env, Tolerations, NodeSelector, etc. These fields will ultimately override the corresponding ones in the default template (originating from ClusterDefinition and ComponentDefinition) to generate the final template for rendering the instance.

Why do we introduce the instance template

In KubeBlocks, a Cluster is composed of several Components, where each Component ultimately oversees multiple Pods and auxiliary objects.

Prior to version 0.9, these pods were rendered from a shared PodTemplate, as defined in either ClusterDefinition or ComponentDefinition. However, this design can’t meet the following demands:

  • For Clusters rendered from the same addon, setting separate scheduling configurations such as NodeName, NodeSelector, or Tolerations.
  • For Components rendered from the same addon, adding custom Annotations, Labels, or ENV to the Pods they manage.
  • For Pods managed by the same Component, configuring different CPU, Memory, and other Resource Requests and Limits.

With various similar requirements emerging, the Cluster API introduced the Instance Template feature from version 0.9 onwards to cater to these needs.

© 2025 ApeCloud PTE. Ltd.