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 WAL-E

WAL-E is a tool designed specifically for interacting with various cloud services and PostgreSQL. Cloud services are often designed to require complex API calls before accepting read or write commands. This makes it somewhat difficult to send them arbitrary files such as PostgreSQL transaction logs we wish to save in a secure location.

The principal benefit of keeping WAL files in a remote cloud location is the same as maintaining offline backups. By moving transaction logs to an external server, we can use them in emergencies or complete datacenter disasters. It's a different form of high availability where we trade the expense and latency of involving distant servers for a major increase in geographical diversity.

WAL-E supports transmitting and retrieving files to several cloud vendors and APIs: