**Is your feature request related to a problem?** Changing the instance size does in-place replacement which causes downtime if we apply the change across multiple DBInstances at the same time with in a cluster. **Describe the solution you'd like** If we can have life-cycle annotation for create-before-destroy that will help reduce the downtime. **Describe alternatives you've considered** We are changing the DBInstance size on one DBInstance at a time, and that is time consuming.