Since the first edition of PostgreSQL Replication many new technologies have emerged or improved. In the PostgreSQL community, countless people around the globe have been working on important techniques and technologies to make PostgreSQL even more useful and more powerful.
To make sure that readers can enjoy all those new features and powerful tools, I have decided to write a second, improved edition of PostgreSQL Replication. Due to the success of the first edition, the hope is to make this one even more useful to administrators and developers alike around the globe.
All the important new developments have been covered and most chapters have been reworked to make them easier to understand, more complete and absolutely up to date.
I hope that all of you can enjoy this book and benefit from it.
This book will guide you through a variety of topics related to PostgreSQL replication. We will present all the important facts in 15 practical and easy-to-read chapters:
Chapter 1, Understanding the Concepts of Replication, guides you through fundamental replication concepts such as synchronous, as well as asynchronous, replication. You will learn about the physical limitations of replication, 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 presents 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 the aspects of synchronous replication.
Chapter 6, Monitoring Your Setup, covers PostgreSQL monitoring.
Chapter 7, Understanding Linux High Availability, presents a basic introduction to Linux-HA and presents a set of ideas for making your systems more available and more secure. Since the first edition, this chapter has been completely rewritten and made a lot more practical.
Chapter 8, Working with PgBouncer, deals with PgBouncer, which is very often used along with PostgreSQL replication. You will learn how to configure PgBouncer and boost the performance of 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.
Chapter 14, Scaling with BDR, describes the basic concepts and workings of the BDR replication system. It shows how BDR can be configured and how it operates as the basis for a modern PostgreSQL cluster.
Chapter 15, Working with Walbouncer, shows how transaction log can be replicated partially using the walbouncer tool. It dissects the PostgreSQL XLOG and makes sure that the transaction log stream can be distributed to many nodes in the cluster.
This guide is a must for everybody interested in PostgreSQL replication. It is a comprehensive book explaining replication in a comprehensive and detailed way. We offer a theoretical background as well as a practical introduction to replication designed to make your daily life a lot easier and definitely more productive.
This book has been written primary for system administrators and system architects. However, we have also included aspects that can be highly interesting for software developers as well—especially when it comes to highly critical system designs.
In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.
Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "We can include other contexts through the use of the include directive."
A block of code is set as follows:
checkpoint_segments = 3 checkpoint_timeout = 5min checkpoint_completion_target = 0.5 checkpoint_warning = 30s
When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
checkpoint_segments = 3
checkpoint_timeout = 5min
checkpoint_completion_target = 0.5
checkpoint_warning = 30sAny command-line input or output is written as follows:
test=# CREATE TABLE t_test (id int4); CREATE TABLE
New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Clicking the Next button moves you to the next screen."
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