Read replicas and failover

What a reader instance does

A reader follows the primary through PostgreSQL streaming replication and serves read-only workloads through a separate endpoint. It can reduce reporting pressure on the primary and provide failover capacity.

Cost model

A reader needs its own compute, memory, storage, backups, monitoring, and network capacity. It therefore adds infrastructure cost. Renviq will show size and price before creation when self-service readers are enabled.

Operational safety

• Send only read traffic to the reader endpoint.
• Monitor lag before using it for freshness-sensitive reads.
• Treat promotion as an incident or planned failover with fencing.
• Test application behavior when the reader is unavailable.
• Do not assume a reader replaces backups.