Do you know this very special feeling when there is something on your mind that just has to be done? I guess when you are in this very special state you should simply sit down, work on your concept and turn it into reality. I guess this is the kind of mood I am in at the moment. After I had stopped working on publications around 10 years ago I did not have the desire to go back to writing for a long time until one day somebody approached me with the idea of writing one more book—this time on PostgreSQL replication. Somehow my first reaction regarding this idea was a plain and straight "Let's do it!". PostgreSQL replication has always fascinated me and it is an essential thing in my everyday life as a professional PostgreSQL consultant, trainer, and business owner.
During the past couple of years I have literally met hundreds of people who are interested in replication and I really hope that this publication can be beneficial to all those people out there who want to use PostgreSQL for work, for education or simply for fun. I, Hans-Jürgen Schönig, and my long-term project partner, true friend, and co-author Zoltan Böszörmenyi have tried to make this book as comprehensive as possible so that as many people as possible can gain knowledge from our work and turn their projects into a full blown success.
Maybe your expectations as a reader are as high as our expectations as authors. So, what better place is there to start working on a book then at 35.000 feet above sea level? Just like 13 years ago when I started to work on my first book—for some reason the first lines of my book are written on an aircraft. This time high above the oil fields of Mosul, northern Iraq, on my way to Dubai.
This book will guide you through a variety of topics related to PostgreSQL replication. We will present all important facts in 13 practical and easy-to-read chapters:
Chapter 1, Understanding Replication Concepts, guides you through fundamental replication concepts such as synchronous as well as asynchronous replication. You will learn about physical limitations of replication and about which options you have and what kind of distinctions there are.
Chapter 2, Understanding the PostgreSQL Transaction Log, introduces you to the PostgreSQL internal transaction log machinery and present concepts essential to many replication techniques.
Chapter 3, Understanding Point-In-Time-Recovery, is the next logical step and outlines how the PostgreSQL transaction log will help you to utilize Point-In-Time-Recovery to move your database instance back to a desired point in time.
Chapter 4, Setting up Asynchronous Replication, describes how to configure asynchronous master-slave replication.
Chapter 5, Setting up Synchronous Replication, is one step beyond asynchronous replication and offers a way to guarantee zero data loss if a node fails. You will learn about all aspects of synchronous replication.
Chapter 6, Monitoring Your Setup, covers PostgreSQL monitoring.
Chapter 7, Understanding Linux High Availability, presents a basic introduction to Linux high availability and presents a set of ideas for making your systems more available and more secure.
Chapter 8, Working with pgbouncer, deals with pgbouncer, very often used along with PostgreSQL replication. You will learn how to configure pgbouncer and boost performance for your PostgreSQL infrastructure.
Chapter 9, Working with pgpool, covers one more tool capable of handling replication and PostgreSQL connection pooling.
Chapter 10, Configuring Slony, contains a practical guide to using Slony and shows, how you can use this tool fast and efficiently to replicate sets of tables.
Chapter 11, Using Skytools, offers you an alternative to Slony and outlines how you can introduce generic queues to PostgreSQL and utilize londiste replication to dispatch data in a large infrastructure.
Chapter 12, Working with Postgres-XC, offers an introduction to a synchronous multimaster replication solution capable of partitioning a query across many nodes inside your cluster while still providing you with a consistent view of the data.
Chapter 13, Scaling with PL/Proxy, describes how you can break the chains and scale out infinitely across a large server farm.