Each Microsoft 365 gateway application requires a SQL Server database to store configuration information. Before deploying the application, you must install SQL Server and prepare the required number of databases. SQL Server can be installed on the Microsoft 365 Application Endpoint Host or on separate hosts if database high availability is required.
If database high availability is not required, the following SQL Server versions and editions can be used:
- SQL Server 2012 Express/Web/Standard/Enterprise (x64)
- SQL Server 2014 Express LocalDB/Express/Web/Standard/Enterprise (x64)
- SQL Server 2016 Express LocalDB/Express/Web/Standard/Enterprise (x64)
- SQL Server 2017 Express LocalDB/Express/Web/Standard/Enterprise (x64)
- SQL Server 2019 Express LocalDB/Express/Web/Standard/Enterprise (x64)
Important: If a SQL Server Express LocalDB database is in use by a running Microsoft 365 gateway application, it is impossible to connect to the database with SQL Server Management Studio or sqlcmd.exe. To connect to the database with SQL Server Management Studio or sqlcmd.exe, you must perform the following actions: stop the corresponding Microsoft 365 gateway site, stop the corresponding Microsoft 365 gateway application, and wait for the database to be released.
If database high availability is required, the following SQL Server versions and editions must be used:
- SQL Server 2012 Standard/Enterprise (x64)
- SQL Server 2014 Standard/Enterprise (x64)
- SQL Server 2016 Standard/Enterprise (x64)
- SQL Server 2017 Standard/Enterprise (x64)
- SQL Server 2019 Standard/Enterprise (x64)
See SQL Server Express LocalDB (x64) if you are going to use SQL Server Express LocalDB (x64). See SQL Server Express/Web/Standard/Enterprise (x64) if you are going to use SQL Server Express/Web/Standard/Enterprise (x64).