Database Tutorial #8: PostgreSQL Replication and High Availability
A single database server is a single point of failure. If it goes down, your application goes down. Replication gives you a copy of your data on another server — for failover, for read scaling, and for backups. How Streaming Replication Works PostgreSQL primary-replica replication works through the Write-Ahead Log (WAL). Every change to the primary is recorded in WAL files. The replica connects to the primary, streams those WAL records, and replays them to stay in sync. ...