Book Image

Becoming KCNA Certified

By : Dmitry Galkin
Book Image

Becoming KCNA Certified

By: Dmitry Galkin

Overview of this book

The job market related to the cloud and cloud-native technologies is both growing and becoming increasingly competitive, making certifications like KCNA a great way to stand out from the crowd and learn about the latest advancements in cloud technologies. Becoming KCNA Certified doesn't just give you the practical skills needed to deploy and connect applications in Kubernetes, but it also prepares you to pass the Kubernetes and Cloud Native Associate (KCNA) exam on your first attempt. The book starts by introducing you to cloud-native computing, containers, and Kubernetes through practical examples, allowing you to test the theory out for yourself. You'll learn how to configure and provide storage for your Kubernetes-managed applications and explore the principles of modern cloud-native architecture and application delivery, giving you a well-rounded view of the subject. Once you've been through the theoretical and practical aspects of the book, you'll get the chance to test what you’ve learnt with two mock exams, with explanations of the answers, so you'll be well-prepared to appear for the KCNA exam. By the end of this Kubernetes book, you'll have everything you need to pass the KCNA exam and forge a career in Kubernetes and cloud-native computing.
Table of Contents (22 chapters)
1
Part 1: The Cloud Era
4
Part 2: Performing Container Orchestration
7
Part 3: Learning Kubernetes Fundamentals
12
Part 4: Exploring Cloud Native
16
Part 5: KCNA Exam and Next Steps

Resource requests and limits

As we were exploring the features of the K8s scheduler previously, have you wondered how Kubernetes knows what is the best node in the cluster for a particular pod? If we create a Deployment with no affinity settings, topology constraints, or node selectors, how can Kubernetes decide what is the best location in the cluster for the application we want to run?

By default, K8s is not aware of how many resources (CPU, memory, and other) each container in a scheduled pod requires to run. Therefore, for Kubernetes to make the best scheduling decisions, we need to make K8s aware of what each container requires for normal operation.

Resource requests

A resource request is an optional specification of how many resources each container in a pod needs. Containers can use more resources than requested if the node where the Pod runs has available resources. The specified request amounts will be reserved on the node where the pod is scheduled.

Kubernetes...