Many databases provide advanced database replication technologies such as Oracle Real Application Clusters (RAC) and Microsoft Cluster Server (MSCS). The failover functionality provided by the drivers does not require any of these technologies, but can work with them to provide comprehensive failover protection. Use the following guidelines for primary and alternate servers to ensure that failover works correctly in your environment:
Alternate servers should mirror data on the primary server or be part of a configuration where multiple database nodes share the same physical data.
If using failover with an Oracle RAC, the primary server must be a primary node and any alternate server must be a secondary node.
If using failover with MSCS, which determines the alternate server for failover instead of the driver, any alternate server specified must be the same as the primary server. For example:
Alternate servers should mirror data on the primary server or be part of a configuration where multiple database nodes share the same physical data.