An interface unit adapted for connecting at least one database to at least one of a plurality of high availability cluster servers (HA cluster servers), wherein each database is adapted to execute a set of database-specific commands and wherein each HA cluster server is adapted to output a set of HA cluster server-specific commands. The interface unit may comprise a first interface layer adapted for receiving each of the set of HA cluster server-specific commands outputted by the HA cluster servers; and a second interface layer adapted for sending each of the set of database-specific commands to the respective databases. The interface unit may be further adapted to map each of the HA cluster server-specific commands to at least one of the database-specific commands.