1. A method for upgrading a database that is still being accessed in an online service, comprising: starting an upgrade process of a database used in the online service; wherein the database being upgraded continues to receive and process requests from web servers for database operations throughout the upgrade process; upgrading a schema of the database currently being utilized to an upgraded schema; wherein the upgraded schema is backwards compatible with the schema; after upgrading the current schema, upgrading web servers of the online service to use the upgraded schema; and the upgraded web servers accessing the database using the upgraded schema.