Using pgactive to support active-active replication - Amazon Relational Database Service
Limitations

Using pgactive to support active-active replication

The pgactive extension uses active-active replication to support and coordinate write operations on multiple RDS for PostgreSQL databases. Amazon RDS for PostgreSQL supports the pgactive extension on the following versions:

  • RDS for PostgreSQL 17.0 and all higher versions

  • RDS for PostgreSQL 16.1 and higher 16 versions

  • RDS for PostgreSQL 15.4-R2 and higher 15 versions

  • RDS for PostgreSQL 14.10 and higher 14 versions

  • RDS for PostgreSQL 13.13 and higher 13 versions

  • RDS for PostgreSQL 12.17 and higher 12 versions

  • RDS for PostgreSQL 11.22

Note

When there are write operations on more than one database in a replication configuration, conflicts are possible. For more information, see Handling conflicts in active-active replication

Topics

Limitations for the pgactive extension

  • All tables require a Primary Key, otherwise Update's and Delete's aren't allowed. The values in the Primary Key column shouldn't be updated.

  • Sequences may have gaps and sometimes might not follow an order. Sequences are not replicated. For more information, see Handling sequences in active-active replication.

  • DDL and large objects are not replicated.

  • Secondary unique indexes can cause data divergence.

  • Collation needs to be identical on all node in the group.

  • Load balancing across nodes is an anti-pattern.

  • Large transactions can cause replication lag.