Amazon Relational Database Service
User Guide (API Version 2014-10-31)

DB Instance and DB Cluster Maintenance and Upgrades

Changes to a DB instance or DB cluster can occur when you manually modify a DB instance or DB cluster, such as when you upgrade the engine version, or when Amazon RDS performs maintenance on a DB instance or DB cluster. Following, you can find information on how to upgrade an engine version and also information on how Amazon RDS performs required maintenance.