While iControl Application Server failures are not common, it is prudent to plan for such an eventuality. Fortunately, recovery from a hardware failure can be ensured by the use of one or more standby Application Server(s). A standby server takes over all the system monitoring and control processes that were running on a main Application Server prior to a failure.

Additionally, unexpected power disruptions, such as might occur during a power failure, can damage the file system on an iControl Application Server. It is strongly recommended that all Application Servers be connected to a standby power source, such as a UPS (Uninterruptible Power Supply), as a preventive measure.

Before putting your Application Server into operation, you should consider implementing a redundancy plan. A redundancy plan defines the use of standby Application Servers in case of hardware failure. This ensures that all the processes that run on the main server(s) will continue to operate uninterrupted.

Redundancy (or recovery) planning is best done at the same time as the system set-up. Full redundancy requires one standby server for each running Application Server. More typically, an iControl system includes one standby server for every five primary Application Servers, since it is unlikely that more than one will fail at the same time.