Book Image

PostgreSQL High Availability Cookbook - Second Edition

By : Shaun Thomas
Book Image

PostgreSQL High Availability Cookbook - Second Edition

By: Shaun Thomas

Overview of this book

Databases are nothing without the data they store. In the event of a failure - catastrophic or otherwise - immediate recovery is essential. By carefully combining multiple servers, it’s even possible to hide the fact a failure occurred at all. From hardware selection to software stacks and horizontal scalability, this book will help you build a versatile PostgreSQL cluster that will survive crashes, resist data corruption, and grow smoothly with customer demand. It all begins with hardware selection for the skeleton of an efficient PostgreSQL database cluster. Then it’s on to preventing downtime as well as troubleshooting some real life problems that administrators commonly face. Next, we add database monitoring to the stack, using collectd, Nagios, and Graphite. And no stack is complete without replication using multiple internal and external tools, including the newly released pglogical extension. Pacemaker or Raft consensus tools are the final piece to grant the cluster the ability to heal itself. We even round off by tackling the complex problem of data scalability. This book exploits many new features introduced in PostgreSQL 9.6 to make the database more efficient and adaptive, and most importantly, keep it running.
Table of Contents (18 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback

Installing the necessary components

The two main components of the software we use in this chapter are Corosync and Pacemaker. Each of these comprises, or depends on, several other elements and prerequisites. For now, we'll simply refer to the entire suite as Pacemaker, as it comprises the bulk of how we will control the failover system.

This recipe should be relatively short, as we will only discuss the installation of Corosync and Pacemaker, not their configuration.

Getting ready

Red-Hat-based systems such as Fedora, CentOS, and Scientific Linux will already have Pacemaker in their repositories. Debian and its derivatives such as Ubuntu also include Pacemaker as an optional install from standard repositories. Red Hat Enterprise Linux (RHEL) itself, however, only offers the software as a paid add-on, available at this URL:

Whatever choice you make, it shouldn't be necessary to compile Pacemaker from source on most Linux distributions.

How to do it.....