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

Applying bonus kernel tweaks

Most operating system kernels are optimized for generalized use. While this does not preclude operation as a server, we have to change a few settings to fully utilize our available hardware. This isn't simply a series of configuration modifications meant to increase performance, but critical kernel-related tweaks meant to prevent outages.

Though, while we're on the subject, there's no reason to not include purely performance-enhancing changes. Getting the most out of our hardware prevents unnecessary operating strain on existing resources. A server running too close to its limits cannot be considered highly-available; an unexpected increase in demand can render a server unusable under the right circumstances.

Getting ready

While the following settings are based on Linux servers, some of the concepts are universal. We'll try to provide enough information to illustrate this. However, keep that in mind for this recipe. Otherwise, look for a directory named /etc/sysctl...