Certified Kubernetes Application Developer (CKAD) Practice Test

A rolling update in Kubernetes is a powerful mechanism that facilitates updating applications with minimal or no downtime. This is achieved by incrementally replacing the old version of the application with the new version without taking the entire application offline. During a rolling update, Kubernetes ensures that a specified number of pods are kept available and healthy while others are gradually being updated to the new version. This method allows users to maintain continuous service availability, as some instances of the old version remain operational while others are being replaced.

Kubernetes orchestrates this process by creating new pods with the updated version and gradually shutting down the old ones, which prevents service interruption. This is particularly important in production environments where downtime can significantly impact user experience and operational efficiency. The key is that rolling updates provide a controlled and automated way to manage deployment changes, ensuring that users can always access the application throughout the update process.