Book Image

The KCNA Book

By : Nigel Poulton
Book Image

The KCNA Book

By: Nigel Poulton

Overview of this book

There is a huge benefit in building small, specialized, single-purpose apps that can self-heal, auto scale, and update regularly without needing downtime. Kubernetes and cloud-native technologies come in handy in building such apps. Possessing the knowledge and skills to leverage Kubernetes can positively enhance possibilities in favor of architects who specialize in cloud-native microservices applications. ‘The KCNA Book’ is designed to help those working in technology with a passion to become certified in the Kubernetes and Cloud-Native Associate Exam. You will learn about containerization, microservices, and cloud-native architecture. You will learn about Kubernetes fundamentals and container orchestration. The book also sheds light on cloud-native application delivery and observability. It focuses on the KCNA exam domains and competencies, which can be applied to the sample test included in the book. Put your knowledge to the test and enhance your skills with the all-encompassing topic coverage. Upon completion, you will begin your journey to get the best roles, projects, and organizations with this exam-oriented book.
Table of Contents (12 chapters)
9
8: Sample test
Appendix B: Sample Test answers

Container storage

Containers are designed to be ephemeral and stateless. Ephemeral means they’re designed to be short-lived, and if they fail you replace them with new ones instead of fixing them. Stateless means they were never designed to store data. In fact, if a container fails, all data inside it is lost.

With this in mind, containers should store data in external systems. It’s a very simple model where application code runs in containers and application data is stored outside of them. A simple cloud example running on AWS might have business application code running inside containers that store the data they generate in AWS elastic block store (EBS) volumes. This way, if any of the application containers fail, the data still exists in the EBS volumes. A similar on-premises example might have application code running inside containers and the data they generate in volumes on a shared NetApp storage system. Other clouds and storage systems exist.

This model decouples...