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

Configuring PgBouncer safely

Once PgBouncer is installed, we need to configure it to honor our ideal pool size calculations. The settings included with the supplied configuration file are for demonstration purposes only and are unlikely to match our requirements. This situation is easy to rectify, but it requires a bit of research on our part.

Getting ready

The PgBouncer settings are explained in detail in the example configuration file. However, we suggest making full use of the service documentation while following this recipe. We will endeavor to explain important parameters, but there's more available than we cover here.

When we installed PgBouncer, we ensured the configuration directory was writable by the postgres system user, which is the same user that owns the PostgreSQL service. For the sake of simplicity, we suggest using either this user or a root-capable user that can modify files on its behalf.

We also need the calculated pool size from the Determining connection costs and limits...