ELI5: What is Failback?
When your main bike gets a flat tire, you ride your backup bike. Failback is when the flat tire is fixed and you switch back to riding your main bike again.
Definition
Failback is the process of returning operations back to the primary system after it has been restored to normal functioning following a failure event that caused a failover to the secondary/standby system. Failback must be carefully planned and executed to minimize disruption, as moving traffic back to the primary involves another transition period and potential brief service interruption.
Key Details
- Failback is the reverse of failover — it returns services to the original primary infrastructure
- Must be carefully planned: verify primary is fully functional before initiating failback
- May involve data synchronization from secondary back to primary (especially after extended failover)
- Should be scheduled during low-traffic periods to minimize user impact
- Some organizations choose to keep operating on secondary infrastructure until a maintenance window
Connections
- Parent: resilience-and-redundancy — failback is the complement to failover in resilient system design
- See also: failover