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

Resiliency

Resilient applications and infrastructure can self-heal when things break. In fact, sometimes we call resiliency “self-healing”.

A simple infrastructure example is a node pool. Most cloud platforms let you create a pool of virtual servers called a node pool. If you configure one with 10 virtual servers, and one of them fails, the system can self-heal by spinning up a new node and automatically adding it to the pool.

Kubernetes offers self-healing capabilities for applications and infrastructure. For example, if Kubernetes knows you need 5 containers for a web front-end microservice, and one of them fails, it spins up a new one so you still have 5.

Although these are simple examples, combining resilient applications with resilient infrastructure is extremely powerful.

Loose coupling and building for failure

A key principle when designing resilient systems is to expect things to fail. This forces you to build stuff that can handle failures. A popular and...