CompTIA DataSys+ (DS0-001)Database DeploymentHard
A database administrator is planning to deploy a new highly available database system for an e-commerce platform. The requirement is that in case of a primary database failure, a standby replica must automatically take over with minimal downtime and no data loss. Which replication strategy BEST meets these requirements?
- AAsynchronous Replication
- BLogical Replication
- CSynchronous Replication
- DSemi-synchronous Replication
Show answer & explanationAnswer & explanation
Correct answer: C. Synchronous Replication
Synchronous replication ensures that a transaction is committed on both the primary and at least one replica before it's considered complete. This guarantees no data loss in case of a primary failure and enables automatic failover with minimal downtime.
Why the other options are wrong
- A. Asynchronous replication allows for potential data loss on failover because transactions are committed on the primary before being confirmed on the replica.
- B. Logical replication replicates data changes based on logical data representation, not physical blocks, and does not inherently guarantee zero data loss or automatic failover for high availability in the same way as synchronous physical replication.
- D. Semi-synchronous replication waits for replica acknowledgment but might not guarantee zero data loss if the replica crashes after acknowledging but before fully writing.
Synchronous Replication
A database replication method where a transaction is not considered committed until it has been successfully written to both the primary and at least one replica.
- Guarantees zero data loss in the event of a primary failure.
- Introduces higher write latency compared to asynchronous replication.
- Essential for high-availability systems where data integrity is paramount.
Memory trick: Sync for Safety, Async for Speed.