We migrated from AWS to GCP with minimal downtime

Description and use

The team migrated PostgreSQL from AWS to GCP with minimal downtime, using logical replication and a snapshot for final sync.

The team needed to move a production PostgreSQL database from AWS to GCP while keeping downtime to a minimum.

The migration completed with less than 2 minutes of downtime, maintaining the 5 % SLA and preserving all data and configurations.

1. Created a Cloud SQL PostgreSQL 12 instance with identical configuration to the AWS RDS instance.
2. Enabled logical replication on the AWS RDS instance and set up a replication slot.
3. Configured the Cloud SQL instance as a subscriber to the replication slot.
4. Monitored replication lag and ensured it stayed below 1 s.
5. Performed a final data sync by taking a snapshot of the AWS RDS instance and restoring it to Cloud SQL.
6. Updated DNS and load balancer to point to the GCP instance.
7. Decommissioned the AWS RDS instance after verifying application stability.

We migrated from AWS to GCP with minimal downtime

The database was hosted on Amazon RDS PostgreSQL 12.6, with a 1.5 TB data volume and a 30 GB WAL archive.

We performed a final data sync by taking a snapshot of the AWS RDS instance and restoring it to Cloud SQL.