How to Achieve Low Downtime Updates on RDS with Blue/Green Deployments

AWS RDS supports blue/green deployments to facilitate database maintenance with minimal downtime, allowing changes to be made on a staging (green) instance before promoting it to production (blue). This method is particularly beneficial for critical databases, minimizing service interruptions during updates like engine version changes. During an update, Pulumi sets up a temporary blue/green deployment, performs requested changes on the green instance, and then switches over, deleting the old instance. Although this strategy extends the update duration, it ensures continuous availability. Important considerations include the lack of support for custom checks and clusters, potential manual cleanup if the update fails, and the possibility of resource ID changes, although connection details remain consistent. The method is ideal for updates requiring a maintenance window, such as engine version, parameter group, or storage changes.