Overview of Blue/Green Deployment

When you create a blue/green deployment from an existing standalone blue (source) DB system, the deployment creates a green (target) DB system and prepares it with the selected MySQL version, shape, configuration, and storage settings. The deployment also creates a replication channel to keep the target synchronized with the source until you are ready to switch over.

The deployment tracks the relationship between the source DB system, target DB system, active DB system, and replication channel. While the target DB system is prepared, the source DB system continues to serve client connections. You can monitor the deployment lifecycle state, lifecycle details, and switchover status. After the create operation completes, validate the green target DB system. When you request switchover, the service reevaluates readiness before proceeding. The switchover workflow blocks writes on the source, waits for the target to apply the required transactions, and moves the primary endpoint to the target DB system.

Switchover may impose a short downtime and interrupt client connections while the service blocks writes on the source DB system and moves the primary endpoint to the target DB system.

Updating, moving, or deleting the deployment does not affect the associated resources including the source and target DB system, replication channel, backups, storage, data, or network setup. A deployment cannot be updated, moved, or deleted if it is in UPDATING state and has an operation, such as a switchover, in progress. If you delete the deployment before the switchover starts, you cannot switch over to the target DB system and the DB system upgrade does not complete.

After the switchover is complete, the source DB system is retained. If you no longer need the source DB system, manually delete that DB system to avoid being billed. See Deleting a DB System.