Use Taints and Tolerations

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🌙 Lab

🗒 Tutorial

Details

The ability to influence the way Pods are scheduled to provide the best performance, reduce running costs, and make Kubernetes cluster management easier is an essential skill for an administrator to master. Taints and tolerations work with Node Affinity to attract Pods to a set of nodes. Taints and tolerations have the opposite effect by allowing nodes to repel Pods. Frequent use cases for taints and tolerations include:

• Identifying nodes with special hardware.
• The ability to dedicate nodes to specific application Pods.
• The ability to define custom conditions to evict a Pod from a node.

Taints allow the Kubernetes administrator to prevent unwanted Pods from executing on a predefined set of nodes. Tolerations allow any Pods to deploy onto a node with a matching taint. Together, these allow the administrator to fine-tune how Pods schedule to nodes.

Important: Taints and tolerations cannot ensure that a Pod schedules to a specific node. The Kubernetes scheduler can deploy a Pod onto any node without a taint that repels it. Instead, use node affinity when controlling where Pod scheduling is required.

Objectives

In this tutorial, you will learn:

• The difference between a taint and a toleration
• How to use taints and tolerations to influence application deployment on Oracle Cloud Native Environment

Prerequisites

• Installation of Oracle Cloud Native Environment
  • a single control node and two worker nodes