Question 1
A financial institution is implementing a disaster recovery solution using Dell RecoverPoint for a critical online transaction processing (OLTP) database. The primary and secondary sites are separated by 500 km. The compliance department mandates a Recovery Point Objective (RPO) of zero, but initial tests with synchronous replication show an unacceptable 30% degradation in application performance due to latency. Which replication mode offers the best compromise between the strict RPO requirement and application performance?
Answer and explanation
Correct answer: D
While true synchronous replication over 500 km causes performance issues, semi-synchronous mode (or features like write-folding in some platforms) provides a compromise. It acknowledges the host write immediately after it's cached locally, while the replication to the remote site happens in the background. This greatly reduces application latency while still aiming for a near-zero RPO, which is a much better balance for this scenario than pure asynchronous (which can't guarantee zero data loss) or forcing synchronous replication that cripples the application.