A standalone SAP application server on EC2 occasionally loses its underlying host. The team wants automatic recovery that keeps the instance ID, private IP and attached volumes. Which mechanism fits?
Show answer and explanation
Answer: C
The recover action restarts an instance on new hardware within the same Availability Zone while keeping its instance ID, private and public IP addresses, Elastic IP associations, EBS volumes and metadata, which is what a stateful SAP application server needs when its host fails. It is triggered by an alarm on the system status check, which reports problems with the physical host rather than the guest. A scheduled reboot does not respond to failure, Config only records state, and S3 events are unrelated.
Why the other options are wrong
- A. A nightly reboot is scheduled maintenance, not a response to host failure, and it causes downtime without recovering from the event.
- B. Config evaluates and records compliance; marking an instance non-compliant does not move it to healthy hardware.
- D. An S3 event is triggered by object activity and has no relationship to EC2 host health.
Exam tip. StatusCheckFailed_System plus the recover action preserves instance identity.