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 and configuring etcd

In order for Patroni to reliably determine or define the identity of the primary PostgreSQL instance, we need a distributed key-value layer. In this recipe, we'll be installing etcd to fulfil that role.

The etcd maintainers appear to have designed it to operate primarily in nameless virtual containers. This means we just need to download it and place some binaries in appropriate locations. It's not an ideal installation with reliable configuration files and other expected components, but that's easily rectified if we decide to rely on etcd long-term.

Let's get started.

Getting ready

The etcd service doesn't seem to be a commonly provided package in many Linux distributions. The project itself moves rapidly as well; the version changed four times while this book was being written. As such, we recommend obtaining the latest stable release provided at this URL:

While we use 3.0.14 as the version number in our instructions, don...