US Patent 11379211 Fencing execution of external tools during software changes

Implementations of the present disclosure include methods, systems, and computer-readable storage mediums for upgrading applications. Actions include receiving an upgrading request for an original table of an application, generating an upgraded table including a structure matching the original table, setting a session variable to initiate an application upgrade, and adding a set of triggers to the original table to selectively control read operations and write operations for the original table and the upgraded table based on the session variable.