A standby system is a second computer system that is available in the background to protect a primary system and takes over its tasks in the event of a fault in the primary system. A standby system increases the availability of the IT system concerned. In order to automate the takeover of these services, cluster manager software is often used which detects the failure of the primary system without the intervention of an administrator and automatically carries out the process of service takeover, known as failover .
Some manufacturers of application and database software such as Oracle and Sybase offer their own solutions for standby systems without cluster software . Oracle enables the creation and administration of a standby database on a standby system with Oracle Dataguard , while Sybase offers a solution based on replication . In addition to the manufacturer-specific solutions, there are also independent solutions that can also manage heterogeneous database landscapes and entire systems (including application servers, file systems, etc. incl. IP switching).