What Is Failover?

By Author: Ted Starsky
Total Articles: 11
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Computer systems play the key role in today’s business. That is why the services they offer should be protected from any disruption. For example, by means of a failover.


Failover is a system backup mode in which the functions of primary components, such as computer processor, storage server, system or network are taken over by their corresponding secondary system components when the primary components are unable to function for some reason. The reasons can vary from unexpected failures to scheduled downtime. Failover can refer to any aspect of a system from a personal computer to the whole network. System designers can provide their systems with the failover capability of any of its components. It is an indispensable part of a system which strives to achieve high availability - it is an integral part of disaster recovery. In business continuity planning high availability, ...
... constant accessibility and reliability of systems is the target - this is exactly what failover was made for. A characteristic of failover is that it generally happens unassisted and without any warning. The user is not even aware of the system component failure since he can still use it normally, without any interruption. It automatically and transparently to the user redirects requests from the failed or down system to the backup system. There are basically two types of failovers – automatic and manual. In the first However, some system using automatic failovers may require human approval to operate a failover. It usually consists of a procedure in which a message is sent to the authorized technician who approves of it, and then it operates automatically. Manual failover requires far more support – here the technicians restore the database manually. The reverse of failover is failback. It is a process in which the system or its components that underwent a failover are restored back to their normal activity.