Book Image

Mastering Kubernetes - Fourth Edition

By : Gigi Sayfan
3.3 (3)
Book Image

Mastering Kubernetes - Fourth Edition

3.3 (3)
By: Gigi Sayfan

Overview of this book

The fourth edition of the bestseller Mastering Kubernetes includes the most recent tools and code to enable you to learn the latest features of Kubernetes 1.25. This book contains a thorough exploration of complex concepts and best practices to help you master the skills of designing and deploying large-scale distributed systems on Kubernetes clusters. You’ll learn how to run complex stateless and stateful microservices on Kubernetes, including advanced features such as horizontal pod autoscaling, rolling updates, resource quotas, and persistent storage backends. In addition, you’ll understand how to utilize serverless computing and service meshes. Further, two new chapters have been added. “Governing Kubernetes” covers the problem of policy management, how admission control addresses it, and how policy engines provide a powerful governance solution. “Running Kubernetes in Production” shows you what it takes to run Kubernetes at scale across multiple cloud providers, multiple geographical regions, and multiple clusters, and it also explains how to handle topics such as upgrades, capacity planning, dealing with cloud provider limits/quotas, and cost management. By the end of this Kubernetes book, you’ll have a strong understanding of, and hands-on experience with, a wide range of Kubernetes capabilities.
Table of Contents (21 chapters)
19
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Index

Advanced scheduling

One of the strongest suits of Kubernetes is its powerful yet flexible scheduler. The job of the scheduler, put simply, is to choose nodes to run newly created pods. In theory the scheduler could even move existing pods around between nodes, but in practice it doesn’t do that at the moment and instead leaves this functionality for other components.

By default, the scheduler follows several guiding principles, including:

  • Split pods from the same replica set or stateful set across nodes
  • Schedule pods to nodes that have enough resources to satisfy the pod requests
  • Balance out the overall resource utilization of nodes

This is pretty good default behavior, but sometimes you may want better control over specific pod placement. Kubernetes 1.6 introduced several advanced scheduling options that give you fine-grained control over which pods are scheduled or not scheduled on which nodes as well as which pods are to be scheduled together or separately.

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