Realtime means a request in flight is retried if there's a failure. Said a different way, the load balancer already knows about a spare at all times. This is co

Realtime means a request in flight is retried if there's a failure. Said a different way, the load balancer already knows about a spare at all times. This is compared to a ~5 minute downtime if spawning a replacement EC2 instance is required. Nice idea on the hot spare instances however.