PGConf.Russia 2018

WAL-G is simple and effective disaster recovery tool for PostgreSQL using cloud storages. In its core functionality, WAL-G is the successor of WAL-E rewritten in Go. But there is one new neat feature - delate-backups. WAL-G delta-backups, whenever possible, stores only pages, changed since the previous backup. In this talk, I'm going to describe development process of this feature.

Surprisingly, most important and complicated question was the design of the interface: WAL-e is simple and comprehensive, keeping these properties was goal #1. Technical details of implementation were covering some underwater stones too. Besides these, I want to discuss the perspective of technological development and future coordination of recovery tools developers.

Azure Database for PostgreSQL is a managed database service built for developers using the community PostgreSQL database technology you love. Learn how you can leverage the managed service and the key capabilities that the service offers which enables you as a developer to focus on developing apps. Using customer stories and experiences including live demos, we will walk through best practices and demonstrate how this service integrates with the other Azure services.

Patroni is a Python application to create high-availability PostgreSQL clusters based on the streaming replication. It is used by Red Hat, IBM Compose, Zalando and many other companies. This tutorial will highlight Patroni architecture, provide attendees with hands-on experience of configuring high-availability PostgreSQL clusters with Patroni, describe how to take advantage of numerous additional features and give an opportunity to learn more about common mistakes related to running Patroni and its troubleshooting.

In order to take most out of the Patroni tutorial one needs a laptop with git, vagrant and virtual box installed.

Vagrant can be obtained from https://www.vagrantup.com Virtualbox is at https://www.vagrantup.com

Alternatively, one can install your Linux distribution packages (or use homebrew on Mac).

Once Vagrant and Virtualbox are installed one can run the Patroni VM by issuing the following commands:

$ git clone https://github.com/alexeyklyukin/patroni-training
$ cd patroni-training
$ vagrant up

When the setup concludes Patroni box can be accessed via ssh using vagrant ssh command.

It's not a secret for anyone that statistics can not be transferred with a major upgrade. For small and not heavily loaded databases this is not a problem, you can quickly collect new statistics. But we have databases with a volume of about 5TB and a load of about 100k rps, for which it became a big problem: taking off without statistics, the replicas could not even replay WAL. In my report I'll tell you what tricks we went to upgrade these databases with requirements of 100% read only availability, about what mistakes were made, and about how these errors were painfully corrected. The result of these errors was the extension called "pg_dirty_hands", in which we will collect various hacks, which can be last resort to repair data corruption.