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

Monitoring the resources

As we have explained in the previous chapters, a cluster resource is a highly available service that is made available through at least one of the nodes. Among the resources that we configured up until this point, we can mention the virtual IP, the replicated storage device, the web server, and the database server. You can refer to Chapter 4, Real-world Implementations of Clustering, where we added constraints that indicated how (in what order) and where (in which node) the cluster resources should be started.

Either pcs status or pcs resource show, the preferred alternative, will list the names and status of all currently configured resources.


If you specify a resource using its ID (that is, pcs resource show virtual_ip), you will see the options for the configured resource. On the other hand, if --full is specified (pcs resource show --full), all configured resource options will be displayed instead.

If a resource is started on the wrong node (for example, if...