Google says Cloud SQL's MySQL upgrade preview keeps database connections unchanged

Google has introduced managed blue-green deployments in preview for Cloud SQL for MySQL, allowing teams to test an upgraded database copy before switching production traffic without changing application connections. The service continuously replicates data into the upgraded copy. At switchover, it briefly makes the original read-only, completes synchronization and transfers the existing IP address, instance name and backups to the new primary. The preview supports standalone MySQL primary instances, including High Availability configurations. Teams can initiate upgrades through the console or CLI scripts; PostgreSQL support is forthcoming.