· Cloud Migration · 2 min read
Zero-Downtime Database Migration to Cloud SQL
Migrating your core database is risky. Learn how we use Database Migration Service (DMS) for a seamless switch-over with minimal impact on operations.
The database is the heart of most applications. Moving it is like performing open-heart surgery. A minute of downtime can mean thousands in lost revenue and broken trust with your customers. The old “Dump and Restore” method, which meant stopping the app for hours, just doesn’t cut it anymore.
The Strategy: Continuous Replication
We use Google’s Database Migration Service (DMS) to perform a secure, reliable migration. The process uses Change Data Capture (CDC) to keep the old and new databases in perfect sync until the final moment.
1. The Initial Load
First, DMS takes a snapshot of your existing database. While this massive data load is happening, your app keeps working as normal. DMS quietly makes a note of any changes that happen during this time. Once the snapshot is loaded, it replays those changes to “catch up.”
2. Staying in Sync
Now, the new Cloud SQL database acts like a Read Replica of your old master database. It stays in sync, lagging behind by only milliseconds. This phase can create run for weeks, letting you:
- Verify all the data arrived correctly.
- Point your analytics tools to the new database to check performance.
- Let the database “warm up.”
3. The Switch
When everyone is ready:
- Pause: We briefly pause writes to the application.
- Wait: We wait a few seconds for the cloud database to process the very last few updates.
- Promote: We tell the Cloud SQL database that it is now the Boss (Primary).
- Switch: We update the app to talk to the new database.
This shrinks the downtime window from hours to mere seconds.
Why Cloud SQL?
Moving to managed Cloud SQL (for PostgreSQL, MySQL, or SQL Server) means you can stop worrying about the boring maintenance work:
- Backups: They happen automatically.
- Availability: If one server fails, another takes over automatically.
- Security: Your data is encrypted at rest and in transit.
At Alps Agility, we treat your data with extreme caution, ensuring everything matches perfectly before we flip the switch.
Planning a critical migration? Don’t risk data loss (or your sleep). Consult our Database Migration experts for a risk-free strategy.
