Manual Takeovers have an n+1 redundancy scheme. That is, iControl doesn’t limit the number of Main Application Servers. iControl limits the number of Application Servers acting in a Backup capacity to one within a single Redundancy Group. If more than one Backup server is required, they should be put into separate N+1 Redundancy Groups.

For example, consider two Main (online) Application Servers plus one Backup Application Server. The Backup is in a standby state and doesn’t run any processes used in normal operation. To address the GSM as a single point-of-failure problem or GSM load balancing, we may want to run two GSMs. GSM duties are thus load-balanced between the two Mains. When an operator initiates a Manual Takeover from one of the Mains to the Backup, that portion of the GSM duties being handled by the taken-over Main is switched to the Backup along with all other services of this Application Server and its identity.

A Backup Application Server replicates the configuration data and identities of the n Application Servers. From the iControl—Redundancy configuration page, a list of replication profiles can be specified. The default replication frequency is 24 hours. This means that in the case of an Application Server failure, any changes performed to the Application Server profile in the previous 24 hours could be lost.