When Amazon starts and stops autoshifts
When you enable zonal autoshift for a resource, you authorize Amazon to shift away resource traffic for an application from an Availability Zone during events, on your behalf, to help reduce time to recovery.
To achieve this, zonal autoshift uses Amazon telemetry to detect, as early as possible, that there is an Availability Zone impairment that could potentially impact customers. When Amazon starts an autoshift, traffic to configured resources immediately starts shifting away from the impaired Availability Zone that could potentially impact customers.
Zonal autoshift is a capability designed for customers who have pre-scaled their application resources for all Availability Zones in an Amazon Web Services Region. You should not rely on scaling on demand when an autoshift or practice run starts.
Amazon ends an autoshift when it determines that the Availability Zone has recovered.