Slony is one of the most widespread replication solutions in the field of PostgreSQL. It is not only one of the oldest replication implementations, it is also one that has the most extensive support by external tools, such as pgAdmin3. For many years, Slony was the only viable solution available for the replication of data in PostgreSQL. Fortunately, the situation has changed and a handful of new technologies have emerged.
In this chapter, we will take a deep look at Slony, and you will learn how to integrate Slony into your replication setup. You will also find out which problems you can solve using Slony. A wide variety of use cases and examples will be covered.
The following topics will be covered in this chapter:
Installing Slony
The Slony system architecture
Replicating tables
Deploying DDLs
Handling failovers
Common pitfalls