SAA-C03 Design Secure Architectures Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  The database remains unavailable until an administrator manually creates a new instance.

  Why it's wrong here

  Multi-AZ RDS does not require manual intervention after a primary instance failure. The service automatically detects the loss of the primary, promotes the standby instance in the same Region, and updates the DNS endpoint to point to the new primary. Because the failover is automated, an administrator does not need to create a new instance manually, which would extend recovery time significantly and contradict the purpose of Multi-AZ deployment.

  When this WOULD be correct

  This would be correct if the question described a Single-AZ RDS deployment without Multi-AZ or automated failover, where an administrator must manually restore from a snapshot or create a new instance.

• ✓

  RDS automatically fails over to the standby instance in the same Region and keeps the same endpoint.

  Why this is correct

  Multi-AZ RDS is built for high availability. If the primary instance becomes unavailable, AWS automatically promotes the standby in the same Region and updates the DNS behind the database endpoint. Applications keep using the same connection string, so failover is largely transparent. This reduces downtime without requiring manual intervention or application changes.

• ✗

  Traffic is routed to a read replica in another Region for immediate continuity.

  Why it's wrong here

  A read replica in another Region is primarily used for read scaling and disaster recovery, not for automatic failover during a Multi-AZ outage. Unlike a Multi-AZ standby, which is a synchronous copy in the same Region, a cross-region read replica uses asynchronous replication and would require manual promotion plus a change to the application connection string. RDS does not automatically route traffic to a read replica; doing so would serve stale data and not provide the immediate continuity promised by Multi-AZ.

  When this WOULD be correct

  If the question were about disaster recovery using Amazon RDS cross-Region read replicas and asked how to promote a read replica to a primary for continuity after a regional failure, then traffic could be routed to the promoted read replica.

• ✗

  The failed primary continues serving traffic while the standby synchronizes in the background.

  Why it's wrong here

  A failed primary instance cannot continue serving traffic because the failure condition means it is no longer operational or reachable. When the primary fails, RDS promotes the standby instance to be the new primary, and the old primary is either replaced or removed. Synchronization between the primary and standby occurs continuously before failure; it does not happen in the background while the primary is down, so the standby cannot serve while syncing because failover has already occurred.

  When this WOULD be correct

  This option would be correct if the question described a scenario where RDS is configured with a Multi-Region read replica and the primary fails, but the application is designed to use the read replica for reads only, not for failover. However, for write continuity, a manual promotion would be needed.

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The SAA-C03 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official SAA-C03blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”

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