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

Preparing systems for the stack

Patroni, etcd, and HAProxy have a few dependencies necessary for them to function. Most of these are easily obtained, so the amount of work in this recipe should be relatively minimal.

Let's get this part done so we can proceed to the really interesting stuff!

Getting ready

This recipe depends on few potentially supplementary packages that are missing from many Linux distributions. Red-Hat-based systems need to install the EPEL package for the appropriate Red Hat platform from the following URL:

Users of Debian-based distributions should be able to follow this recipe as written.

How to do it...

For this recipe, we will need at least three PostgreSQL servers. For demonstration purposes, we'll assume they are named pg1, pg2, and pg3. Follow these steps on all three servers:

  1. Debian-based systems should use this apt-get command to install as many distribution-provided packages as possible:
sudo apt-get install python-psycopg2 python...