If a network is equipped with redundant resources, such as mirrored servers or tandem load balancers, the secondary device can assume the duties of the primary should the primary fail. This can be done manually or automatically depending on the setup.
The means of failure recognition and recovery used by Real Application Clusters.
The process of transferring processes from a failed server to a functional server automatically.
The process of nondisruptively routing data to an alternate data path or device in the event of device or connection failure.
A backup operation that automatically switches to a standby system (database, server or network), if the primary system fails or is temporarily shut down. Failover is an important fault tolerance function of PACS.
Failover is a feature of RAID in which a pair of RAID controllers that are in communication with one another simultaneously process the same input/output commands to an array of disks. If one of the controllers fails, the surviving controller detects the failure and automatically assumes the function of the failed controller. For more information, see Failover and Failback in the Storage Management Concepts chapter.
an irreversible transition of a standby database to the primary role
When an application Web server fails, Oracle Web Cache automatically distributes the load over the remaining application Web servers and polls the failed application Web server for its current up/down status until it is back online.
The process by which a unit monitors the site router WAN links, using SNMP, and adjusts its link rate accordingly if the router switches to a lower-bandwidth backup WAN link. Failover should not be confused with hot standby, in which two units act as a redundant pair.
When there is a failure or changeover, failover allows you to manually or automatically switch processing and/or applications to another device, with no data loss or corruption. (8/97)
Backup operational mode in which the functions of a system component (such as a processor, server, network, or database) are assumed by secondary system components when the primary component becomes unavailable through either failure or scheduled down time.
When an origin server fails, OracleAS Web Cache automatically distributes the load over the remaining origin servers and polls the failed origin server for its current up/down status until it is back online. In a cache cluster environment, OracleAS Web Cache transfers ownership of the content of the failing member to the remaining cluster members.
Network Registrar feature (as described in RFC 2131) that provides for multiple, redundant DHCP servers, whereby one server can take over in case of a failure. DHCP clients can continue to keep and renew their leases without needing to know or care which server is responding to their requests.
Failover is a backup operational mode in which the function of a system component is assumed by secondary system components when the primary component becomes unavailable through either failure or scheduled down time.
Procedure whereby operations of applications are shifted over from production server to backup server in a prior-planned manner eliminating planned downtime of an entity.
The process of automatically resuming operation of a system on a back up system when the primary system fails.
This is when one device stops working, and another device automatically takes its place. Basically, the work done by the device figuratively fails over onto the other device.
Data is immediately and nondisruptively routed to an alternate data path or device in the event of an event of an adapter, cable, channel controller or other device.
The automatic replacement of a failed system component with a properly functioning one. Most often used in the context of redundant external array controllers. If one of the controllers fails, failover enables the second controller to take over the failed controller's I/O load.
(n.) The automatic relocation of a resource group or a device group from a current primary node to a new primary node after a failure has occurred.
Also called fallover, the sequence of events when a primary or server machine fails and a secondary or backup machine assumes the primary workload. This is a disruptive failure with a short recovery time.
In a server cluster, the means of providing high availability. Upon failure, either of a resource in a group or of the node where the group is online, the Cluster service takes the group offline on that node, and then brings it online on another node. See also node; resource.
The automatic substitution of a functionally equivalent system component for a failed one. The term failover is most often applied to intelligent controllers connected to the same storage devices and host computers. If one of the controllers fails, failover occurs, and the survivor takes over its I/O load. (Provided by SNIA)
Failover is the capability to switch over to a redundant or standby computer system, network or connection upon the failure of the previously active system, network or connection. Failover is usually automatic and generally happens without human intervention.
Switching to a redundant or standby server, system, or network on failure or unplanned termination of the active server, system, or network. Failover happens automatically, and is often built-in to continuously available systems.
The process of detecting a system failure and migrating functionality to a backup system
When one device stops working and another device automatically takes its place; typically after a set amount of time has lapsed since the first device stopped responding. Basically, the work done by the failed device falls over onto the other device.
The process of failure recognition and recovery. In a cold failover cluster configuration, an application running on one cluster node is transparently migrated to another cluster node. During this migration, clients accessing the service on the cluster see a momentary outage and may need to reconnect once the failover is complete.
During failover, Adaptive Server migrates to another machine which takes over the responsibility of managing the failed over Adaptive Server. Failover can occur because of either a scheduled maintenance or a failure of Adaptive Server or the machine running Adaptive Server.
A procedure that switches user and client access from a primary database to a standby database, particularly in the event of a failure that interrupts operations at the primary database, or access to the primary database. Failover is an important fault-tolerance feature for systems that require high availability. See also failback.
The transfer of operation from a failed component (e.g., controller, disk drive) to a similar, redundant component to ensure uninterrupted data flow and operability.
An operational mode where the function of a system component is assumed by a standby component when the primary system component becomes unavailable because of failure or scheduled down time.
Ability to reconfigure a computing system to utilize an alternate active component when a similar component fails.
The process of allocating a resource group to another node to another, according to a failover policy. A failover may be triggered by the failure of a resource, a change in the node membership (such as when a node fails or starts), or a manual request by the administrator.
Capability to re-route signaling traffic as required between related ASPs in the event of failure or if the currently used ASP is unavailable (from primary MGC to backup MGC, for example). Failover also applies to the return to service of a previously unavailable process.
In the event of a physical disruption to a network component, data is immediately rerouted to an alternate path so that services remain uninterrupted. Failover applies both to clustering and to multiple paths to storage. In the case of clustering, one or more services (such as Exchange) is moved over to a standby server in the event of a failure. In the case of multiple paths to storage, a path failure results in data being rerouted to a different physical connection to the storage.
The process of taking resource groups offline on one node and bringing them back online on another node. When a resource group goes offline, all resources belonging to that group go offline. The offline and online transitions occur in a predefined order, with resources that are dependent on other resources taken offline before and brought online after the resources upon which they depend. See also: failover policy; failover time; IIS Server Instance resource; offline; possible owners; resource
Process by which a standby or secondary system component automatically takes over the functions of an active or primary component when the primary component fails or is temporarily shut down or removed for servicing. During failover, the system continues to perform normal operations with little or no interruption in service.
Failover is the capability to switch over automatically to a redundant or standby computer server, system, or network upon the failure or abnormal termination of the previously active server, system, or network. Failover happens without human intervention and generally without warning, unlike switchover.