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

Getting acquainted with PCS

We are getting closer to actually setting up the cluster. Before diving into that task, we need to become familiar with PCS—the core component of our cluster—so to speak, which will be used to control and configure pacemaker and corosync. To begin doing that, we can just run PCS without arguments, as follows:


This returns the output shown in the following screenshot, which provides a short explanation of each option and command available in PCS:

We are interested in the Commands section, where the actual categories of clustering that can be managed through this tool are listed, along with a brief description of their usage. Each of them supports several capabilities, which can be shown by appending the word help to pcs [category]. For example, let's' see the functionality that is provided by the cluster command (which by the way, we will use shortly):

pcs cluster help
Usage: pcs cluster [commands]...
Configure cluster for use with pacemaker