Book Image

CentOS High Performance

By : Gabriel Cánepa
Book Image

CentOS High Performance

By: Gabriel Cánepa

Overview of this book

CentOS is the enterprise level Linux OS, which is 100% binary compatible to Red Hat Enterprise Linux (RHEL). It acts as a free alternative to RedHat's commercial Linux offering, with only a change in the branding. A high performance cluster consists in a group of computers that work together as one set parallel, hence minimizing or eliminating the downtime of critical services and enhancing the performance of the application. Starting with the basic principles of clustering, you will learn the necessary steps to install a cluster with two CentOS 7 servers. We will then set up and configure the basic required network infrastructure and clustering services. Further, you will learn how to take a proactive approach to the split-brain issue by configuring the failover and fencing of the cluster as a whole and the quorum of each node individually. Further, we will be setting up HAC and HPC clusters as a web server and a database server. You will also master the art of monitoring performance and availability, identifying bottlenecks, and exploring troubleshooting techniques. At the end of the book, you’ll review performance-tuning techniques for the recently installed cluster, test performance using a payload simulation, and learn the necessary skills to ensure that the systems, and the corresponding resources and services, are being utilized to their best capacity.
Table of Contents (13 chapters)
CentOS High Performance
About the Author
About the Reviewers

Adding DRBD as a PCS cluster resource

You will recall how in Chapter 2, Installing Cluster Services and Configuring Network Components, we added a virtual IP address to the cluster. Now, it's time to do the same with the DRBD resource that we have just created and configured.

Before doing that, however, we must point out that one of the most distinguishing features of the PCS command-line tool that we first introduced back in Chapter 2, Installing Cluster Services and Configuring Network Components, is its ability to save the current cluster configuration to a file, to which you can add further settings using command-line tools. Then, you can use the resulting file to update the running cluster configuration.

To retrieve the cluster configuration from the Cluster Information Base (CIB) and save it to a file named drbd0_conf in the current working directory, use the following command to make sure you started the cluster first:

pcs cluster start --all

Then save the cluster configuration to the...