Technology Fundamentals
Failover
Definition
Failover is the process of automatically switching to a redundant or standby computer server, system, hardware component or network upon the failure or abnormal termination of the previously active application, server, system, hardware component, or network.
Why It Matters
Failover is a crucial part of building highly available systems. It ensures that service can continue uninterrupted even if a primary component fails, minimizing or eliminating downtime.
Contextual Example
A primary database server has a standby "hot spare" that is constantly kept in sync. If the primary server crashes, the system detects the failure and automatically promotes the standby server to become the new primary, with users experiencing little to no interruption.
Common Misunderstandings
- Failover is an automatic process. A manual switchover is called a "switchover".
- Failover systems are essential for mission-critical applications where downtime is unacceptable.