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

Connecting to PgBouncer

Once PgBouncer is installed, configured, and operational, we still need to utilize it. How do we connect to PgBouncer instead of PostgreSQL?

Getting ready

Make sure PgBouncer is configured and running. Take a look at the Configure PgBouncer safely recipe. Then, execute this at the command line to check for the service:

pgrep -lf pgbouncer

We should see a line similar to this:

21281 /usr/bin/pgbouncer -d /etc/pgbouncer/pgbouncer.ini

If this is not the case, we need help beyond the scope of this book. Feel free to check the PgBouncer mailing list for assistance. The community is willing to help too, so let them.

How to do it...

If our PostgreSQL server is on, we can connect to PgBouncer by using port 6432. With psql, we can connect to the postgres database through PgBouncer with this command:

psql -p 6432 -h postgres

With PgAdmin, we will just change the connection settings to resemble this:

How it works...

PgBouncer works like a simulated PostgreSQL...