Book Image

PostgreSQL 12 High Availability Cookbook - Third Edition

By : Shaun Thomas
Book Image

PostgreSQL 12 High Availability Cookbook - Third Edition

By: Shaun Thomas

Overview of this book

Databases are nothing without the data they store. In the event of an outage or technical catastrophe, immediate recovery is essential. This updated edition ensures that you will learn the important concepts related to node architecture design, as well as techniques such as using repmgr for failover automation. From cluster layout and hardware selection to software stacks and horizontal scalability, this PostgreSQL cookbook will help you build a PostgreSQL cluster that will survive crashes, resist data corruption, and grow smoothly with customer demand. You’ll start by understanding how to plan a PostgreSQL database architecture that is resistant to outages and scalable, as it is the scaffolding on which everything rests. With the bedrock established, you'll cover the topics that PostgreSQL database administrators need to know to manage a highly available cluster. This includes configuration, troubleshooting, monitoring and alerting, backups through proxies, failover automation, and other considerations that are essential for a healthy PostgreSQL cluster. Later, you’ll learn to use multi-master replication to maximize server availability. Later chapters will guide you through managing major version upgrades without downtime. By the end of this book, you’ll have learned how to build an efficient and adaptive PostgreSQL 12 database cluster.
Table of Contents (17 chapters)

Installing and configuring Patroni

Patroni is the primary coordinating component of our stack. As we can see from diagram in The stack subsection, it is involved in every element of the stack to some degree. Although it ties all of the stack elements together, we're installing it next specifically because of how tightly it integrates with the key-value layer and PostgreSQL.

If a PostgreSQL server is already running, Patroni will adopt it. If not, Patroni will create a new instance based on how it's configured. We've already established that the key-value store distributes the same information across the entire cluster, so the first established server also becomes the primary node for the cluster. Any subsequent Patroni instance will start as, or transform itself into, a replica.

This means that it's critically important to get this part right. So, pay special...