PGCon2015 - final

PGCon 2015
The PostgreSQL Conference

Heikki Linnakangas
Day Talks - Day 4 - Friday - 2015-06-19
Room DMS 1160
Start time 10:00
Duration 00:45
ID 811
Event type Lecture
Track 9.5 Features
Language used for presentation English

Warm standby done right

With 9.5, it's finally possible

People has been setting up warm standby systems with streaming replication since version 9.0, and even longer with file-based log-shipping. However, there has been a few pitfalls that many people don't know about, while others have simply accepted the risks.

PostgreSQL 9.5 brings a bunch of new features and subtle changes that make warm standby setups more robust than ever. In 9.5, the interaction between a WAL archive and failover has been revised. pg_rewind makes it possible to resynchronize an old master server after failover - even an unplanned one. Replication slots, already introduced in 9.4, make the behaviour of a standby falling behind nicer.

This presentation explains the changes, and why they were needed. Finally, I'm going to walk through setting up a simple, robust, two server hot standby system, using only built-in tools and simple shell scripts, taking advantage of the new features.