11. Streaming Replication

Synchronous streaming replication was implemented in version 9.1. It is a single-master-multi-slaves type of replication, where the terms “master” and “slaves” are usually referred to as primary and standbys respectively.

This native replication feature is based on log shipping, a general replication technique in which the primary server continuously sends WAL data to the standby servers, which then replay the received data immediately.

This chapter focuses on how streaming replication works and covers the following topics:

• How streaming replication starts up.
• How data is transferred between the primary and standby servers.
• How the primary server manages multiple standby servers.
• What is Replication Slots introduced in version 9.4.