Jan Wieremjewicz wants to know if you really need it:
Active-active, also referred to as multi-primary, is a setup where multiple database nodes can accept writes at the same time and propagate those changes to the others. In comparison, regular streaming replication in PostgreSQL allows only one node (the primary) to accept writes. All other nodes (replicas) are read-only and follow changes.
In an active-active setup:
- There is no single point of write.
- Applications can write to any node.
- The database needs a way to sort out conflicts when two nodes try to concurrently change the same data.
Read on for some of the challenges around this, tooling that is available, and thoughts on when this can be important.