CLF-C02 Cloud Technology and Services Practice Question
A company runs a customer relationship management (CRM) application on a single Amazon RDS for PostgreSQL instance. The application experiences heavy read traffic during business hours, often causing the primary database to become overloaded with SELECT queries. The company needs a solution that offloads read queries to a separate database endpoint and provides automatic failover to a standby database in a different Availability Zone if the primary fails. Which combination of Amazon RDS features should the company use to meet these requirements?
⚠ Common exam trap
Many candidates assume Multi-AZ alone can handle read offloading because the standby is available, but AWS explicitly prevents reads from the Multi-AZ standby to maintain consistency, making Read Replicas necessary for read scaling.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Multi-AZ deployment with one or more Read Replicas
It combines Multi-AZ deployment for automatic failover to a standby in a different Availability Zone with Read Replicas to offload SELECT queries to a separate database endpoint. Multi-AZ ensures high availability by synchronously replicating data to a standby instance, while Read Replicas asynchronously replicate data to handle read-heavy traffic without burdening the primary.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Multi-AZ deployment only
Why it's wrong here
Multi-AZ deployment provides automatic failover to a hot standby in another Availability Zone by maintaining a synchronous copy, so the CRM remains available if the primary fails. However, the standby is inactive for reads and cannot serve SELECT queries until a failover occurs; it exists only to take over on failure. Thus the solution protects availability but does not reduce the primary's read load, so it does not fully address the stated problem.
When this WOULD be correct
A company needs high availability and automatic failover for a production database with no need to offload read traffic. The question would specify that read performance is not a concern, only fault tolerance across AZs.
- ✗
Read Replicas only
Why it's wrong here
Read Replicas only offload read traffic through separate endpoints, but they use asynchronous replication and do not take over automatically if the primary instance fails. In a CRM outage, you would have to manually promote a replica and repoint the application, causing significant downtime and possibly losing recent writes that had not yet been replicated. This addresses read performance but leaves the core availability requirement unmet, making it an incomplete solution.
When this WOULD be correct
A company needs to offload read queries from a primary database to improve read performance, but does not require automatic failover or high availability. For example, a reporting application that can tolerate brief downtime during manual promotion.
- ✓
Multi-AZ deployment with one or more Read Replicas
Why this is correct
A Multi-AZ RDS deployment creates a synchronously replicated standby in a different Availability Zone; if the primary fails, Amazon RDS automatically flips to the standby with minimal downtime. Adding one or more Read Replicas gives you dedicated read-only endpoints that use asynchronous replication and can absorb analytical or reporting traffic, reducing load on the primary. Together, the configuration provides both high availability for write operations and elastic read scaling, which directly meets the requirement to reduce load while keeping the CRM available.
- ✗
Cross-Region Read Replicas only
Why it's wrong here
Cross-Region Read Replicas provide read scaling and disaster recovery across AWS Regions, but they do not provide automatic failover in the primary region. If the primary database fails, you would still need to manually promote a replica, and the solution does not address high availability within a single region.
When this WOULD be correct
A company needs to offload read queries from a primary database and also requires disaster recovery across AWS regions, with the ability to promote a read replica to a standalone database in another region if the primary fails. The question would specify that the standby must be in a different AWS region, not just a different Availability Zone.
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 CLF-C02 exam frequently reuses these exact scenarios with slightly different constraints.
✓Multi-AZ deployment with one or more Read ReplicasCorrect answer▾
Why this is correct
A Multi-AZ RDS deployment creates a synchronously replicated standby in a different Availability Zone; if the primary fails, Amazon RDS automatically flips to the standby with minimal downtime. Adding one or more Read Replicas gives you dedicated read-only endpoints that use asynchronous replication and can absorb analytical or reporting traffic, reducing load on the primary. Together, the configuration provides both high availability for write operations and elastic read scaling, which directly meets the requirement to reduce load while keeping the CRM available.
✗Multi-AZ deployment onlyWrong answer — click to see why▾
Why this is wrong here
Multi-AZ deployment provides automatic failover to a standby in a different AZ but does not offload read traffic; the standby is not used for reads. The requirement to offload SELECT queries requires Read Replicas.
★ When this WOULD be the correct answer
A company needs high availability and automatic failover for a production database with no need to offload read traffic. The question would specify that read performance is not a concern, only fault tolerance across AZs.
Why candidates choose this
Candidates may think Multi-AZ includes read scaling because the standby is available, but AWS RDS Multi-AZ standby is not accessible for reads; it only serves as a failover target.
✗Read Replicas onlyWrong answer — click to see why▾
Why this is wrong here
Read Replicas only offload read traffic but do not provide automatic failover to a standby in a different Availability Zone; they require manual promotion for failover, which does not meet the automatic failover requirement.
★ When this WOULD be the correct answer
A company needs to offload read queries from a primary database to improve read performance, but does not require automatic failover or high availability. For example, a reporting application that can tolerate brief downtime during manual promotion.
Why candidates choose this
Candidates may think that Read Replicas alone can handle both read offloading and failover, overlooking that automatic failover is a distinct feature of Multi-AZ deployments.
✗Cross-Region Read Replicas onlyWrong answer — click to see why▾
Why this is wrong here
Cross-Region Read Replicas are designed for disaster recovery and reducing latency for geographically distant users, not for offloading read traffic within the same region or providing automatic failover to a standby in a different Availability Zone within the same region.
★ When this WOULD be the correct answer
A company needs to offload read queries from a primary database and also requires disaster recovery across AWS regions, with the ability to promote a read replica to a standalone database in another region if the primary fails. The question would specify that the standby must be in a different AWS region, not just a different Availability Zone.
Why candidates choose this
Candidates may confuse 'different Availability Zone' with 'different region' or think that cross-region replicas inherently provide failover, not realizing that Multi-AZ is needed for automatic failover within a region.
Analysis generated from the official CLF-C02blueprint 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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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CLF-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CLF-C02 exam.