Google Cloud Platform for Developers

Horizontal scaling

While vertical scaling on Cloud SQL is relatively straightforward and painless, a single instance can only scale to a certain point. Teams looking to scale beyond this may wish to investigate horizontal scaling options on Cloud SQL. As we've discussed, Cloud SQL supports read-only replicas for use in high availability configurations. Read-only replicas may also be used to lighten the load of read-heavy databases.

Other methods for horizontal scaling include master-slave configurations and sharding. Cloud SQL does not support these configurations natively, though they may be implemented externally using industry tools such as ProxySQL. Note, however, that these are not use cases that Cloud SQL has been designed for. Teams ...