SAA-C03 Design Resilient 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.

• ✗

  Create a read replica in a different Availability Zone and configure the application to fail over manually.

  Why it's wrong here

  A read replica uses asynchronous replication and cannot be promoted to a standalone primary without a failover process that incurs replication lag, potential data loss, and manual steps. Configuring the application for manual failover requires updating connection strings and does not offer automatic detection of the primary's failure, so it fails to meet the need for rapid, unattended recovery. Also, reading from a replica would serve stale data until it catches up, which is not acceptable for a database that must remain consistent and available.

  When this WOULD be correct

  A question where the application can tolerate some downtime but needs to offload read traffic, and the exam asks for a cost-effective way to improve read scalability without automatic failover.

• ✓

  Enable Multi-AZ for the RDS DB instance so AWS manages a standby in another Availability Zone with automatic failover.

  Why this is correct

  RDS Multi-AZ creates a synchronous standby replica in a separate Availability Zone and automatically flips the DNS endpoint to the standby within seconds if the primary instance fails, a network partition occurs, or an AZ becomes unavailable. This is the only option that provides true high availability with no manual intervention, making it the correct answer because it directly addresses resilience to an entire Availability Zone failure.

• ✗

  Switch the database to use EBS snapshots more frequently and restore in case of failure.

  Why it's wrong here

  EBS snapshots are a backup mechanism, not a high-availability feature; restoring from a snapshot creates a brand-new DB instance, which takes time to provision and does not preserve the original endpoint. The restore process also loses any transactions committed after the last snapshot, resulting in a potentially high RPO, and the RTO is measured in minutes or more. This approach is appropriate for disaster recovery, not for meeting an aggressive RTO with automatic failover.

  When this WOULD be correct

  A question where the goal is to minimize data loss (low RPO) for a non-critical application that can tolerate downtime for recovery, and the requirement is to implement a cost-effective backup strategy without needing automatic failover.

• ✗

  Pin the DB to a specific instance type with higher CPU credits to prevent CPU-related disconnects.

  Why it's wrong here

  Burstable instance classes (t2/t3/t4g) earn CPU credits, but pinning the DB to a specific instance type with higher CPU credits only addresses potential CPU throttling during sustained load. It does nothing to protect against an Availability Zone outage, which is the underlying failure scenario. Higher CPU credits cannot provide redundancy, failover capability, or automatic re-routing of traffic, so this option would leave the database still vulnerable to AZ-level loss.

  When this WOULD be correct

  For a question where the application experiences intermittent performance degradation due to CPU credit exhaustion on a burstable instance (e.g., t3/t4g), and the goal is to eliminate CPU-related throttling without changing architecture.

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?”

Go deeper

Related to this question