Book Image

PostgreSQL Replication

By : Zoltan Böszörmenyi, Hans-Jürgen Schönig
Book Image

PostgreSQL Replication

By: Zoltan Böszörmenyi, Hans-Jürgen Schönig

Overview of this book

<p>PostgreSQL offers a comprehensive set of replication related features, which can be used to make your database servers more robust and way more scalable. Unleashing the power of PostgreSQL provides the user with countless opportunities and a competitive advantage over other database systems. To make things more powerful, PostgreSQL can be used in conjunction with a handful of sophisticated tools serving various different needs such as queuing, logical replication, or simplified transaction log handling.</p> <p>"PostgreSQL Replication" is a practical, hands-on guide to PostgreSQL replication. It will provide you with the theoretical background as well as simple examples showing you how to make replication work on your system. A broad toolchain will be presented along with mature PostgreSQL-core technology.</p> <p>"PostgreSQL Replication" starts with an introduction to replication concepts as well as the physical limitations of different replication solutions. You will be guided through various techniques such as Point-In-Time-Recovery, transaction-log-based replication and you will be introduced to a set of replication-related tools. In the final chapter you will learn to scale PostgreSQL to many different servers using PL/Proxy.</p> <p>You will learn how to reset PostgreSQL to a certain point in time and figure out how to replicate data in many ways. You will deal with both synchronous as well as asynchronous replication. In addition to that, the book covers important topics, such as Slony, and upgrades with virtually no downtime. We will also cover important performance-related topics to make sure your database setups will provide you with high speed AND high availability.</p> <p>"PostgreSQL Replication" contains all the information you need to design and operate replicated setups. You will learn everything you need to know for your daily work and a lot more.</p>
Table of Contents (20 chapters)
PostgreSQL Replication
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Taking base backups


In the previous section, you have seen that enabling archiving takes just a handful of lines and offers a great deal of flexibility. In this section, we will see how to create a so called base backup, which can be used to apply XLOG later on. A base backup is an initial copy of the data.

Tip

Keep in mind that the XLOG itself is more or less worthless. It is only useful in combination with the initial base backup.

host	replication  all     192.168.0.34/32      md5

In PostgreSQL, there are two main options to create an initial base backup:

  • Using pg_basebackup

  • Traditional copy/rsync based methods

The following two sections will explain in detail how a base backup can be created:

Using pg_basebackup

The first and most common method to create a backup of an existing server is to run a command called pg_basebackup, which was introduced in PostgreSQL 9.1.0. Basically pg_basebackup is able to fetch a database base backup directly over a database connection. When executed on the slave...