Pgactive
lastmod 2025-07-18created 2025-07-181 edits
Active-active replication extension for Postgres
About
- An active-active replication extension for PostgreSQL, built and released by AWS
- When data writes and updates are needed on multiple PostgreSQL instances, it lets you build a structure where multiple instances can accept changes and replicate them concurrently, instead of the traditional active-standby model in which a single instance alone accepts changes
- Suited to scenarios such as high-availability database setups across multiple regions, minimizing write latency, blue/green application updates, and bidirectional data migration
- Uses logical replication to support conflict detection, write conflict resolution, format conversion for the target database, and more
Active-active replication concepts
- Replication is a technology that synchronizes changes between databases
- In the traditional PostgreSQL active-standby structure, only one instance accepts changes and the rest are read-only, so one place acts as the single source of data
- pgactive provides an active-active replication topology, allowing data writes on multiple instances at the same time
- This approach suits environments that need multiple write points, such as multi-region deployments or bidirectional migrations
- The active-active model requires separate management of conflicts, latency, and some feature limitations
Core technology: logical replication
- Logical replication sends data in a format that external systems can interpret
- Logical replication makes it possible to implement various add-on features on the target database, such as conflict detection, write conflict resolution, and query conversion
- PostgreSQL introduced basic logical replication in version 10 in 2017, but active-active replication requires additional features
- Owing to PostgreSQL's design, such features can be developed and applied as extensions
- The PostgreSQL development community is also gradually adding these features to the core project