Introduction

Some of the most important components for any production database are there to achieve fault tolerance, availability 24 x 7, and redundancy. It is for this purpose we have different high availability and replication solutions available for PostgreSQL.

From a business perspective, it is important to ensure data availability 24 x 7 in the event of a disaster situation or in the event of a database crash due to disk or hardware failure. In such situations, it becomes critical to ensure that a duplicate copy of data is available on a different server or a different database so that the seamless failover could be achieved even when the primary server/database is unavailable.

In this chapter, we will talk about various high availability and replication solutions including some popular third-party replication tools such as Slony, Londiste, and Bucardo. We will also discuss block level replication using DRBD, and finally we will set up a PostgreSQL Highly Extensible Cluster, that is,...