CompTIA DataSys+ (DS0-001)Database DeploymentHard
A database administrator is performing a pre-deployment validation for a new critical financial application's database. The application demands extremely high availability and zero data loss in the event of a primary database failure. Which replication strategy should the administrator verify is configured and functioning correctly?
- ASynchronous replication
- BDelayed replication
- CSemi-synchronous replication
- DAsynchronous replication
Show answer & explanationAnswer & explanation
Correct answer: A. Synchronous replication
Synchronous replication ensures that a transaction is committed on both the primary and at least one replica before returning success to the client. This guarantees zero data loss (RPO=0) in the event of a primary failure, which is critical for financial applications demanding such stringent data integrity.
Why the other options are wrong
- B. Delayed replication introduces an intentional time lag, making it unsuitable for applications requiring high availability and zero data loss.
- C. Semi-synchronous replication provides a compromise, ensuring that at least one replica has received the transaction before the primary commits, but does not guarantee it has been applied, still potentially allowing for minimal data loss.
- D. Asynchronous replication allows for data loss (RPO > 0) because transactions are committed on the primary before being replicated, which does not meet the 'zero data loss' requirement.
Database Replication Types
Different methods of copying and synchronizing data between database instances to ensure high availability, fault tolerance, and read scalability.
- Asynchronous: Primary commits first, then replicates. Fastest, potential data loss.
- Synchronous: Primary commits only after replica confirms receipt/commit. Zero data loss, higher latency.
- Semi-synchronous: Primary commits after replica acknowledges receipt. Balances performance and data safety.
Memory trick: Synchronize for safety, async for speed, semi for a blend.