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

Listing PgBouncer client connections

In addition to PostgreSQL server connection status, PgBouncer's administration console can provide details regarding clients within its queue. Maintaining a healthy and active PgBouncer queue is the key to high throughput over limited resources. In this case, we artificially limited the amount of server connections available to clients, which means that there is potential for stubborn or broken clients to prevent connection turnover.

This, of course, will effectively remove the connections from the pool, creating a bottleneck that could lead to choking transaction throughput. Let's explore the PgBouncer console a bit more to learn what it knows about the database clients attempting to communicate with PostgreSQL.

Getting ready

In this section, we will continue our previous exploration into the PgBouncer console. Check the Listing PgBouncer client connections recipe for a refresher. Remember to use the pgbouncer database name to enter the administration console...