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

Identifying horizontal candidates

Before we can really decide how to spread our data across several database servers, we need to find appropriate candidates. To do this, we should start at the database level for databases that are extremely active. What qualifies as extremely active? Databases that fit any of these criteria are a good start:

  • The database experiences more than 10 million transactions per day
  • The database handles more than 100 million queries per day
  • The database writes more than 100 million tuples per day

Once we've chosen a database for horizontal scalability, we need to look at its tables and decide which should be distributed. Tables that make good choices are those that fit one or more of the following criteria:

  • Tables that contain more than 10 million rows
  • Tables that experience more than 1 million writes per day
  • Tables that are larger than 10 GB

This recipe will discuss easy ways to find prospective tables for further study.

Getting ready

This recipe uses an existing database...