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You're reading from Learn OpenShift Deploy, build, manage, and migrate applications with OpenShift Origin 3.9

Product type Paperback

Published in Jul 2018

Publisher Packt

ISBN-13 9781788992329

Length 504 pages

Edition 1st Edition

Languages

Tools

Openshift

Concepts

Containerization

Authors (3):

Denis Zuev

Artemii Kropachev

Aleksey Usov

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Table of Contents (28) Chapters

Title Page

Packt Upsell

Contributors

Preface

1. Containers and Docker Overview FREE CHAPTER

2. Kubernetes Overview

3. CRI-O Overview

4. OpenShift Overview

5. Building an OpenShift Lab

6. OpenShift Installation

7. Managing Persistent Storage

8. Core OpenShift Concepts

9. Advanced OpenShift Concepts

10. Security in OpenShift

11. Managing OpenShift Networking

12. Deploying Simple Applications in OpenShift

13. Deploying Multi-Tier Applications Using Templates

14. Building Application Images from Dockerfile

15. Building PHP Applications from Source Code

16. Building a Multi-Tier Application from Source Code

17. CI/CD Pipelines in OpenShift

18. OpenShift HA Architecture Overview

19. OpenShift HA Design for Single and Multiple DCs

20. Network Design for OpenShift HA

21. What is New in OpenShift 3.9?

1. Assessments

2. Other Books You May Enjoy

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Index

HA in OpenShift

In the previous chapters, we ran our applications on a single node, or sometimes, two nodes. Some might say that if there is more than one OpenShift node in the cluster, it is considered a redundant configuration, but that is far from true.

If we compare standard OpenShift architecture and OpenShift HA, you will see some differences between them:

OpenShift classic architecture

Here we have nodes, masters, storage, and a routing layer consisting of infra nodes. OpenShift HA architecture is quite similar but has one distinct difference—in the routing layer we have load balances that make the overall solution always accessible. All other components are redundant by nature:

OpenShift HA architecture

Virtual IPs

We can see that in OpenShift HA, we have what's called an enterprise load balancer, with two Virtual IPs (VIPs). We need one VIP for traffic to master nodes, and another VIP for traffic to actual OpenShift applications, running on OpenShift nodes within pods: