2 Articles tagged “HA”

High-Availability comes with some impact on your architecture choices, in particular when applied to RDBMS such as Postgres. One such impact is the idea of a failover. When implementing database HA, it is usually expected that both the service and the data are maintained available in the face of operational faults. The most common way to implement resilience includes automated (or manual) failover, where a new primary is elected among a list of standby nodes.

In other words, as soon as Postgres High-Availability is implemented, the roles of your Postgres nodes are dynamic. The fact that a given node is a primary or a standby at any given point in time ceases to be relevant to understanding your architecture. In fact, the only thing that’s now given about the role of a node is that it will change. Otherwise you don’t have failover capability, and then, you probably don’t have HA in the first place, right?

In this article we are going to try and understand what having dynamic roles for Postgres nodes in a HA system means.

We just released pg_auto_failover version 1.6.3 on GitHub, and the binary packages should be already available at the usual PGDG and CitusData places, both for debian based distributions and RPM based distributions too.

This article is an introduction to the pg_auto_failover project: we answer the Five W questions, starting with why does the project exist in the first place?

TL;DR pg_auto_failover is an awesome project. It fills the gap between “Postgres is awesome, makes developping my application so much easier, it solves so many problems for me!” and the next step “so, how do I run Postgres in Production?”. If you’re not sure how to bridge that gap yourself, how to deploy your first production system with automated failover, then pg_auto_failover is for you. It is simple to use, user friendly, and well documented. Star it on the pg_auto_failover GitHub repository and get started today. Consider contributing to the project, it is fully Open Source, and you are welcome to join us.

Buckle up, our guide tour is starting now!

Dimitri Fontaine

PostgreSQL Major Contributor

Open Source Software Engineer